Farm to abattoir conditions and their subsequent effects on behavioural and physiological changes and the quality of beef from extensively-reared Nguni and non-descript steers
- Authors: Njisane, Yonela Zifikile
- Date: 2016
- Subjects: Nguni cattle Beef cattle breeds Beef -- Quality -- South Africa , Slaughtering and slaughter-houses -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/3143 , vital:28324
- Description: The main objective of the study was to determine the effect of farm to abattoir environmental conditions and their subsequent effects on behavioural and physiological responses, as well as the quality of meat from Nguni (NG) and non-descript (ND) beef steers reared extensively on natural pastures. The forty 16 – 19 months old steers (20 ND and 20 NG) used in the current study were grouped together, medically treated, allowed three weeks acclimatizing period and were used in this trial over a four-month period. The weather and periodical variations influence on time budgets and body weights of these steers were determined. Furthermore, the effects of on-farm successive handling on behavioural scores and physiological responses of the same steers were determined. Later in the trial, some pre-slaughter effects on response-behaviour, bleed-out times and selected blood physiological responses were determined. Finally, the effect of genotype, muscle type, lairage duration, slaughter order and stress responsiveness on pH24, temperature, colour (L*, a*, b*, C, HA), thawing (TL) and cooking (CL) losses and Warner Bratzler Shear Force (WBSF) of the meat harvested from the same steers were determined. The daily time budgets of steers in natural pastures changed with temperature, humidity, observation week and time of the day. The grazing behaviour was observed throughout the observation days (> 37 percent); though it was reduced (26.9±2.64 percent) on days with higher temperatures and low humidity. Higher proportions of drinking (1.5±1.04 percent) and standing (20.8±4.63 percent) behaviours prolonged in such weather conditions, which were mostly during midday. The avoidance-related behaviour of the steers during handling varies, with the steers showing more avoidance and aggression in other weeks than some. These variations could however be traced back to the events of that particular day/time of handling. Only Weighing Box (WBS) and stepping (SS) scores differed (P<0.05) with genotype; with more calm NG steers (> 40 percent) and not kicking than the ND steers that were more vocal (20–60 percent) and kicking (> 5 percent). In addition, the weekly behavioural responses were reflected (P<0.05) in the measured cortisol, glucose and lactate. However, regardless of the prominent negative behaviour seen over time, the levels of the measured blood constituents continued to drop. Furthermore, steers of different genotypes displayed similar (P>0.05) response to the identical pre-slaughter conditions they were exposed to. However, steers that were Transport Group 1 (TG1) showed more avoidance (63.2 percent) pre-slaughter than those in TG2 (23.9 percent). Furthermore, all the steers that were in slaughter Group 2 (SG2) showed less avoidance behaviour than those in other groups. Vocalization was observed only for ND steers (5 percent), in TG1 and SG2. Some connections between the observed pre-slaughter activities and some behavioural and physiological changes of these steers were established; with TG1 and SG1 steers showing higher cortisol (140±14.50 and 175.9±17.24 nmol/L, respectively) and lactate (12.4±0.83 and 13.5±1.12 mmolL) levels than the other groups. Lastly, the muscle type, genotype, lairage duration, slaughter order and stress responsiveness have an effect on some meat quality characteristics of the two genotypes; with the L. dorsi muscle having highest WBSF (38.0±1.35N) than the Superficial pectoral muscle (Brisket muscle) (30.7±1.35N). Additionally, steers lairaged for a shorter time produced a L. dorsi with higher WBSF (41.6±2.34N) and a Brisket with lower TL (2.7±0.24 percent). It can therefore be concluded that the conditions and activities at the farm, during transportation, lairaging and slaughter at the abattoir have an influence on some behavioural and physiological changes and the quality of beef harvested from the Nguni and non-descript steers that were extensively-reared in natural pastures. However, the relationship patterns between these different conditions are not clear.
- Full Text:
- Authors: Njisane, Yonela Zifikile
- Date: 2016
- Subjects: Nguni cattle Beef cattle breeds Beef -- Quality -- South Africa , Slaughtering and slaughter-houses -- South Africa
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/3143 , vital:28324
- Description: The main objective of the study was to determine the effect of farm to abattoir environmental conditions and their subsequent effects on behavioural and physiological responses, as well as the quality of meat from Nguni (NG) and non-descript (ND) beef steers reared extensively on natural pastures. The forty 16 – 19 months old steers (20 ND and 20 NG) used in the current study were grouped together, medically treated, allowed three weeks acclimatizing period and were used in this trial over a four-month period. The weather and periodical variations influence on time budgets and body weights of these steers were determined. Furthermore, the effects of on-farm successive handling on behavioural scores and physiological responses of the same steers were determined. Later in the trial, some pre-slaughter effects on response-behaviour, bleed-out times and selected blood physiological responses were determined. Finally, the effect of genotype, muscle type, lairage duration, slaughter order and stress responsiveness on pH24, temperature, colour (L*, a*, b*, C, HA), thawing (TL) and cooking (CL) losses and Warner Bratzler Shear Force (WBSF) of the meat harvested from the same steers were determined. The daily time budgets of steers in natural pastures changed with temperature, humidity, observation week and time of the day. The grazing behaviour was observed throughout the observation days (> 37 percent); though it was reduced (26.9±2.64 percent) on days with higher temperatures and low humidity. Higher proportions of drinking (1.5±1.04 percent) and standing (20.8±4.63 percent) behaviours prolonged in such weather conditions, which were mostly during midday. The avoidance-related behaviour of the steers during handling varies, with the steers showing more avoidance and aggression in other weeks than some. These variations could however be traced back to the events of that particular day/time of handling. Only Weighing Box (WBS) and stepping (SS) scores differed (P<0.05) with genotype; with more calm NG steers (> 40 percent) and not kicking than the ND steers that were more vocal (20–60 percent) and kicking (> 5 percent). In addition, the weekly behavioural responses were reflected (P<0.05) in the measured cortisol, glucose and lactate. However, regardless of the prominent negative behaviour seen over time, the levels of the measured blood constituents continued to drop. Furthermore, steers of different genotypes displayed similar (P>0.05) response to the identical pre-slaughter conditions they were exposed to. However, steers that were Transport Group 1 (TG1) showed more avoidance (63.2 percent) pre-slaughter than those in TG2 (23.9 percent). Furthermore, all the steers that were in slaughter Group 2 (SG2) showed less avoidance behaviour than those in other groups. Vocalization was observed only for ND steers (5 percent), in TG1 and SG2. Some connections between the observed pre-slaughter activities and some behavioural and physiological changes of these steers were established; with TG1 and SG1 steers showing higher cortisol (140±14.50 and 175.9±17.24 nmol/L, respectively) and lactate (12.4±0.83 and 13.5±1.12 mmolL) levels than the other groups. Lastly, the muscle type, genotype, lairage duration, slaughter order and stress responsiveness have an effect on some meat quality characteristics of the two genotypes; with the L. dorsi muscle having highest WBSF (38.0±1.35N) than the Superficial pectoral muscle (Brisket muscle) (30.7±1.35N). Additionally, steers lairaged for a shorter time produced a L. dorsi with higher WBSF (41.6±2.34N) and a Brisket with lower TL (2.7±0.24 percent). It can therefore be concluded that the conditions and activities at the farm, during transportation, lairaging and slaughter at the abattoir have an influence on some behavioural and physiological changes and the quality of beef harvested from the Nguni and non-descript steers that were extensively-reared in natural pastures. However, the relationship patterns between these different conditions are not clear.
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Fatty acid composition, colour stability and lipid oxidation of mince produced from fresh and frozen/thawed fallow deer meat
- Authors: Chido, Chakanya
- Date: 2016
- Subjects: Lipids -- Oxidation Meat -- Preservation Mincemeat
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/2479 , vital:27874
- Description: The aim of the study was to determine the fatty acid composition, colour stability and lipid oxidation of fresh mince produced from fallow deer and to evaluate the effect of frozen storage duration on the retail display shelf life of the mince. A total of 31 fallow deer carcasses were used in the study. After cooling for 24hrs, the carcasses were deboned, external fat from the fore and hindquarter muscles removed and individually vacuum packed. For the first trial, seven fallow deer carcasses were used. Meat from the hind and fore-quarters of each carcass was divided into two equal batches per animal. One batch was minced (through a 5 mm die) and packed into oxygen permeable overwraps and refrigerated at 4°C for a period of eight days under retail display conditions. The second batch was vacuum packed and frozen at -20°C for 2 months at the end of which mince was also produced and monitored over an eight-day period under the same conditions that were used for the fresh mince. Colour, pH, lipid and myoglobin stability was determined. Proximate and fatty acid composition was also determined. No differences (P>0.05) were noted between proximate composition of fresh and frozen/thawed minced meat. The lipid content of fallow deer was 2.4 percent (±0.04). Total n3 fatty acids differed (P<0.05) between treatments and decreased with increased storage and display day. There were significant (P<0.05) treatment and time interactions on all measured colour parameters, TBARS and myoglobin forms. Fresh mince was lighter and had higher redness (a*) and yellowness (b*) values than mince from two months frozen stored meat. Hue angle for fresh mince remained stable throughout display whereas it increased for frozen/thawed mince. Fresh mince had lower TBARS values than frozen/thawed mince. Minced meat produced from frozen/thawed deer meat had higher surface met-myoglobin and total met-myoglobin percentages. Surface and total oxy-myoglobin percentage was higher in fresh mince. The first trial clearly showed colour and lipid stability differences between fresh mince and mince from frozen/thawed meat. It also showed that fresh mince has a longer retail display life than mince produced from frozen/thawed meat (six days and four days, respectively). In the second trial, the effects of frozen storage duration on colour and lipid stability were investigated. Twenty-four fallow deer were used. Twelve were harvested in June (6male 6female) and the other twelve in August (6 male 6female) of the same year.Twenty four hours after harvesting, the fore and hindquarter muscles of the carcasses were deboned, vacuum packed and kept at -20°C until October (i.e. 2months and 4months frozen storage period). Upon thawing, the meat was processed into mince following the same procedure used for the first trialand displayed for a fiveday period under retail display conditions. Frozen duration and gender had no effect (P>0.05) on the proximate composition of fallow deer meat. The total amount of saturated fatty acids (SFA) increased and total amount of poly unsaturated fatty acids (PUFA) decreased as frozen duration and display day increased (P<0.05). Frozen duration affected (P<0.01) lipid oxidation and percentage oxy-myoglobin. Mince pH and all colour parameters (L*, a*, b*,hue and chroma) differed (P<0.05) between treatments on day zero and three. Display day was a significant factor (P<0.05) on all measured parameters. By day three all parameters except pH showed signs of extended oxidation and discolouration as evidenced by reduced redness, decreased colour intensity and high TBARS values. This study showed that prolonged frozen storage negatively affects the colour and lipid stability of meat and increases oxidation of PUFAs during frozen storage. However, the study also suggests that although frozen/thawed meat has a shorter retail display shelf life; the proximate composition of the meat remains unchanged.
- Full Text:
- Authors: Chido, Chakanya
- Date: 2016
- Subjects: Lipids -- Oxidation Meat -- Preservation Mincemeat
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/2479 , vital:27874
- Description: The aim of the study was to determine the fatty acid composition, colour stability and lipid oxidation of fresh mince produced from fallow deer and to evaluate the effect of frozen storage duration on the retail display shelf life of the mince. A total of 31 fallow deer carcasses were used in the study. After cooling for 24hrs, the carcasses were deboned, external fat from the fore and hindquarter muscles removed and individually vacuum packed. For the first trial, seven fallow deer carcasses were used. Meat from the hind and fore-quarters of each carcass was divided into two equal batches per animal. One batch was minced (through a 5 mm die) and packed into oxygen permeable overwraps and refrigerated at 4°C for a period of eight days under retail display conditions. The second batch was vacuum packed and frozen at -20°C for 2 months at the end of which mince was also produced and monitored over an eight-day period under the same conditions that were used for the fresh mince. Colour, pH, lipid and myoglobin stability was determined. Proximate and fatty acid composition was also determined. No differences (P>0.05) were noted between proximate composition of fresh and frozen/thawed minced meat. The lipid content of fallow deer was 2.4 percent (±0.04). Total n3 fatty acids differed (P<0.05) between treatments and decreased with increased storage and display day. There were significant (P<0.05) treatment and time interactions on all measured colour parameters, TBARS and myoglobin forms. Fresh mince was lighter and had higher redness (a*) and yellowness (b*) values than mince from two months frozen stored meat. Hue angle for fresh mince remained stable throughout display whereas it increased for frozen/thawed mince. Fresh mince had lower TBARS values than frozen/thawed mince. Minced meat produced from frozen/thawed deer meat had higher surface met-myoglobin and total met-myoglobin percentages. Surface and total oxy-myoglobin percentage was higher in fresh mince. The first trial clearly showed colour and lipid stability differences between fresh mince and mince from frozen/thawed meat. It also showed that fresh mince has a longer retail display life than mince produced from frozen/thawed meat (six days and four days, respectively). In the second trial, the effects of frozen storage duration on colour and lipid stability were investigated. Twenty-four fallow deer were used. Twelve were harvested in June (6male 6female) and the other twelve in August (6 male 6female) of the same year.Twenty four hours after harvesting, the fore and hindquarter muscles of the carcasses were deboned, vacuum packed and kept at -20°C until October (i.e. 2months and 4months frozen storage period). Upon thawing, the meat was processed into mince following the same procedure used for the first trialand displayed for a fiveday period under retail display conditions. Frozen duration and gender had no effect (P>0.05) on the proximate composition of fallow deer meat. The total amount of saturated fatty acids (SFA) increased and total amount of poly unsaturated fatty acids (PUFA) decreased as frozen duration and display day increased (P<0.05). Frozen duration affected (P<0.01) lipid oxidation and percentage oxy-myoglobin. Mince pH and all colour parameters (L*, a*, b*,hue and chroma) differed (P<0.05) between treatments on day zero and three. Display day was a significant factor (P<0.05) on all measured parameters. By day three all parameters except pH showed signs of extended oxidation and discolouration as evidenced by reduced redness, decreased colour intensity and high TBARS values. This study showed that prolonged frozen storage negatively affects the colour and lipid stability of meat and increases oxidation of PUFAs during frozen storage. However, the study also suggests that although frozen/thawed meat has a shorter retail display shelf life; the proximate composition of the meat remains unchanged.
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Management factors influencing lamb survival from birth to weaning in two ecologically different resource-limited communal farming systems
- Authors: Lungu, Nobuhle
- Date: 2016
- Subjects: Lambs Communal rangelands Lambs--Feeding and feeds
- Language: English
- Type: Thesis , Masters , Animal Science
- Identifier: http://hdl.handle.net/10353/11806 , vital:39108
- Description: The objective of the study was to determine the management factors influencing lamb survival from birth to weaning in two ecologically different resource-limited communal farming systems. An annual flock monitoring study in the sourveld and sweetveld regions was preceded by a household check-all-that-apply (CATA). Lamb management practices and constraints faced in raising lambs in the two regions were determined using the check-all-that-apply technique. The results showed that the majority of the households were male headed (75.70percent) and consisted of the elderly (˃50 years, 79.44percent) who were not employed (82.24percent) and had attended primary school (67.29percent). Wool production was ranked the most important reason for keeping sheep in the two regions. The CATA revealed that the management systems between the two regions differed significantly (p˂0.05) in terms of assisting sheep at lambing, attending to twin births and dipping of mature lambs. Farmers‘ age was associated with the type of management performed (p ˂0.05). None of the farmers in the two regions performed navel dipping. Some of the reported constraints in the sweetveld were theft, diarrhoea and drought while predators and cold weather were the major constraints in the sourveld. The CATA identified vaccination and dipping as the major missing practices in both regions. The study showed differences in the use and choice of CATA terms which suggests that a ―one-size-fits-all‖ approach to solving poor management and sheep production constraints is not applicable. In the monitoring study, the results showed that veld type had no significant effect on the birth weights (2.0±0.09 kg) of the lambs. Type of birth had a significant effect (p<0.05) on the birth weights of the lambs. Single born lambs were 0.41kg heavier (p<0.05) than twin lambs. Single born lambs, however, showed an improvement in weights at 90 and 120 days where they had slightly higher weights than single born lambs. Male lambs were significantly (p<0.05) heavier (2.3±0.12 kg) than the female lambs (1.7±0.06 kg) at birth. The lamb birth were highest (P<0.05) in the hot-dry season. Lambs born in the cold-dry season were the lightest (1.63±0.13 kg). Lambs born in the post- rainy and hot-wet season were not significantly different (P<0.05). Weaning weights were not affected by veld type, birth type and sex, but were affected by season of birth. The lambs born in the hot-dry season had the highest weaning weights. The sourveld had a total pre-weaning mortality of 10.6percent while the sweetveld had a total pre-weaning mortality of 14.2percent. Animal housing from both veld types was poorly designed in terms of security against stock theft, drainage, hygiene, overhead shelter from the rain as well as access to feed and water. It was concluded that lamb management practices in the two regions were not the same. Performance of lambs before weaning differed according to veld type which played a role in feed availability during different seasons.
- Full Text:
- Authors: Lungu, Nobuhle
- Date: 2016
- Subjects: Lambs Communal rangelands Lambs--Feeding and feeds
- Language: English
- Type: Thesis , Masters , Animal Science
- Identifier: http://hdl.handle.net/10353/11806 , vital:39108
- Description: The objective of the study was to determine the management factors influencing lamb survival from birth to weaning in two ecologically different resource-limited communal farming systems. An annual flock monitoring study in the sourveld and sweetveld regions was preceded by a household check-all-that-apply (CATA). Lamb management practices and constraints faced in raising lambs in the two regions were determined using the check-all-that-apply technique. The results showed that the majority of the households were male headed (75.70percent) and consisted of the elderly (˃50 years, 79.44percent) who were not employed (82.24percent) and had attended primary school (67.29percent). Wool production was ranked the most important reason for keeping sheep in the two regions. The CATA revealed that the management systems between the two regions differed significantly (p˂0.05) in terms of assisting sheep at lambing, attending to twin births and dipping of mature lambs. Farmers‘ age was associated with the type of management performed (p ˂0.05). None of the farmers in the two regions performed navel dipping. Some of the reported constraints in the sweetveld were theft, diarrhoea and drought while predators and cold weather were the major constraints in the sourveld. The CATA identified vaccination and dipping as the major missing practices in both regions. The study showed differences in the use and choice of CATA terms which suggests that a ―one-size-fits-all‖ approach to solving poor management and sheep production constraints is not applicable. In the monitoring study, the results showed that veld type had no significant effect on the birth weights (2.0±0.09 kg) of the lambs. Type of birth had a significant effect (p<0.05) on the birth weights of the lambs. Single born lambs were 0.41kg heavier (p<0.05) than twin lambs. Single born lambs, however, showed an improvement in weights at 90 and 120 days where they had slightly higher weights than single born lambs. Male lambs were significantly (p<0.05) heavier (2.3±0.12 kg) than the female lambs (1.7±0.06 kg) at birth. The lamb birth were highest (P<0.05) in the hot-dry season. Lambs born in the cold-dry season were the lightest (1.63±0.13 kg). Lambs born in the post- rainy and hot-wet season were not significantly different (P<0.05). Weaning weights were not affected by veld type, birth type and sex, but were affected by season of birth. The lambs born in the hot-dry season had the highest weaning weights. The sourveld had a total pre-weaning mortality of 10.6percent while the sweetveld had a total pre-weaning mortality of 14.2percent. Animal housing from both veld types was poorly designed in terms of security against stock theft, drainage, hygiene, overhead shelter from the rain as well as access to feed and water. It was concluded that lamb management practices in the two regions were not the same. Performance of lambs before weaning differed according to veld type which played a role in feed availability during different seasons.
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Management practices, milk quality, haemato-chemical biomarkers of free ranging pregnant goats from three genotypes and linear body measurements of their respective kids
- Idamokoro, Emrobowansan Monday
- Authors: Idamokoro, Emrobowansan Monday
- Date: 2016
- Subjects: Milk--Quality Biochemical markers Goat milk
- Language: English
- Type: Thesis , Doctoral , Animal Science
- Identifier: http://hdl.handle.net/10353/11548 , vital:39082
- Description: The broad objective of this study was to assess farmers’ perceptions on the welfare and management practices of pregnant goats and to determine the effect of genotypes and physiological status on doe’s performance (blood metabolites and milk quality) and their respective kid’s linear body measurements of goats reared in an extensive system of production. A survey was conducted among 153 goat farmers to assess their perception on goat mortality and management practices during and after gestation period. The results from the survey showed that 98.7percent of the farmers depended on pastures to feed their pregnant and lactating does. Majority of the farmers (59.9percent) did not vaccinate their dams against diseases before using them for breeding purposes. An aggregate of 77.8percent respondents allowed their does to mate freely on the veld. Most of the respondents (75.2percent) kept their pregnant goats together with other flocks in mud floor pen (kraals) fenced with tree branches. Farmers indicated that, poor diet (32percent), disease (24 percent) and predators (15percent) were some factors that cause mortality in pregnant does. About 66.7percent respondents perceived that, quality diet is a factor that can boost the reproductive performance of pregnant goats. The haemato-biochemical parameters of Nguni, Boer and Non-descript goats at late and early lactation revealed that, Nguni goat had higher (P ˂ 0.05) values of red cell counts (13.37 x1011/L), haemoglobin (9.07 g/dL) and creatine kinase (269.54 U/L) compared to Boer (9.96 x 1011/L, 7.94 g/ dL and 132.16 U/L) and Non-descript goats (12.98 x 1011 /L, 7.85 g/ dL and 143.50 U/L), respectively. The Nguni goats also had higher (P ˂ 0.05) mean values of glucose (3.38 mmol/L), sodium (141.66 mmol/L) and urea content (5.51 mmol/L) compared to Boer (2.96 mmol/L, 135.70 mmol/L and 4.45 mmol/L) and Non-descript goats (2.50 mmol/L, 141.31 mmol/L and 3.90 mmol/L), respectively. The results of blood metabolites also revealed that, there was significant difference (P < 0.05) in the physiological status of goats. The late stage of pregnancy had higher mean values of red cell counts (14.44 x 1011 /L), haemoglobin (8.57 g/dL), haematocrit (0.67 L/L), glucose (3.12 mmol/L), sodium (141.74 mmol/L) and calcium content (2.37 mmol/L) compared to the early stage of lactation (9.77 x 1011/ L, 8.00 g /dL, 0.55 L/L, 2.77 mmol/L, 137.37 mmol/L and 2.23 mmol/L), respectively. Furthermore, it was revealed that, Nguni goats produced (1.2±0.09, 1.3±0.11 and 1.2±0.07 litres per day) more milk (P ˂ 0.05) at early, mid and late stages of lactation than Boer (0.6±0.10, 1.0±0.17 and 0.6±0.09 litres per day) and Non-descript (0.3±0.10, 0.3±0.12 and 0.3±0.09 litres per day) goats. There was significant difference (P ˂ 0.05) of genotypes on milk fat, milk magnesium and sodium contents among Nguni, Boer and Non-descript goats. Lactation stages had a significant effect (P ˂ 0.05) on some milk compositions (fat, protein, lactose and solid non-fat) and mineral profiles (Ca, Mg, Na, K, and Fe) of Nguni goats. Lactation stages had a significant effect (P ˂ 0.05) on fat, protein, lactose and solid non-fat content and mineral profiles (Ca, Mg, Na, K, and Fe) of Nguni goats. Milk protein content of Nguni goat was positively correlated to milk fat but, not in Boer and Non-descript goats. Milk quality parameters from the three goat genotypes possessed relatively moderate milk compositions and mineral profiles which is comparable to some exotic goat breeds. Nguni kids had higher mean weights (7.36 kg, 11.85 kg and 13.72 kg) than the Boer kids (5.20 kg, 7.18 kg and 10.20 kg) and the Non-descript goat kids (5.23 kg, 6.19 kg and 8.01 kg) at weeks 4, 6 and 8 after parturition, respectively. In terms of height at withers, the Nguni kids had higher mean values in heights (41.92 cm, 44.71 cm, 49.38 cm and 55.75 cm) than the Boer kids (35.67 cm, 37.14 cm, 42.40 and 44.20 cm) and the Non-descript kids (36.38 cm, 40.20 cm, 41.14 cm and 43.50 cm) at week 2, 4, 6 and 8 after parturition, respectively. Conversely, there was a positive correlation (P ˂ 0.05) between body lengths and live weights of Nguni goats and not in Boer and Non-descript goats. It was concluded from this study that, the indigenous Nguni, Boer and Non-descript pregnant goats were managed in poor conditions by communal farmers and the perceived causes of mortality of pregnant goats among others include poor feed, diseases and predators. In addition, the Nguni goats had higher mean values in some haematological parameters (red cell counts and haemoglobin) and serum biochemical profiles (glucose, sodium, urea and creatine kinase) than Boer and Non-descript goats during the periods of investigation. Nguni goats also produced more milk at the early and late stages of lactation compared to the Boer and Non-descript goats. The Non-descript goats had a higher mean value of milk fat compared to Nguni and Boer goats. Likewise, the Boer goats were observed to have higher mean value of milk magnesium and sodium content compared to Nguni and Non-descript goats. In terms of body weights and linear body measurments, the Nguni goat kids were superior compared to Boer and Non-descript goats.
- Full Text: false
- Authors: Idamokoro, Emrobowansan Monday
- Date: 2016
- Subjects: Milk--Quality Biochemical markers Goat milk
- Language: English
- Type: Thesis , Doctoral , Animal Science
- Identifier: http://hdl.handle.net/10353/11548 , vital:39082
- Description: The broad objective of this study was to assess farmers’ perceptions on the welfare and management practices of pregnant goats and to determine the effect of genotypes and physiological status on doe’s performance (blood metabolites and milk quality) and their respective kid’s linear body measurements of goats reared in an extensive system of production. A survey was conducted among 153 goat farmers to assess their perception on goat mortality and management practices during and after gestation period. The results from the survey showed that 98.7percent of the farmers depended on pastures to feed their pregnant and lactating does. Majority of the farmers (59.9percent) did not vaccinate their dams against diseases before using them for breeding purposes. An aggregate of 77.8percent respondents allowed their does to mate freely on the veld. Most of the respondents (75.2percent) kept their pregnant goats together with other flocks in mud floor pen (kraals) fenced with tree branches. Farmers indicated that, poor diet (32percent), disease (24 percent) and predators (15percent) were some factors that cause mortality in pregnant does. About 66.7percent respondents perceived that, quality diet is a factor that can boost the reproductive performance of pregnant goats. The haemato-biochemical parameters of Nguni, Boer and Non-descript goats at late and early lactation revealed that, Nguni goat had higher (P ˂ 0.05) values of red cell counts (13.37 x1011/L), haemoglobin (9.07 g/dL) and creatine kinase (269.54 U/L) compared to Boer (9.96 x 1011/L, 7.94 g/ dL and 132.16 U/L) and Non-descript goats (12.98 x 1011 /L, 7.85 g/ dL and 143.50 U/L), respectively. The Nguni goats also had higher (P ˂ 0.05) mean values of glucose (3.38 mmol/L), sodium (141.66 mmol/L) and urea content (5.51 mmol/L) compared to Boer (2.96 mmol/L, 135.70 mmol/L and 4.45 mmol/L) and Non-descript goats (2.50 mmol/L, 141.31 mmol/L and 3.90 mmol/L), respectively. The results of blood metabolites also revealed that, there was significant difference (P < 0.05) in the physiological status of goats. The late stage of pregnancy had higher mean values of red cell counts (14.44 x 1011 /L), haemoglobin (8.57 g/dL), haematocrit (0.67 L/L), glucose (3.12 mmol/L), sodium (141.74 mmol/L) and calcium content (2.37 mmol/L) compared to the early stage of lactation (9.77 x 1011/ L, 8.00 g /dL, 0.55 L/L, 2.77 mmol/L, 137.37 mmol/L and 2.23 mmol/L), respectively. Furthermore, it was revealed that, Nguni goats produced (1.2±0.09, 1.3±0.11 and 1.2±0.07 litres per day) more milk (P ˂ 0.05) at early, mid and late stages of lactation than Boer (0.6±0.10, 1.0±0.17 and 0.6±0.09 litres per day) and Non-descript (0.3±0.10, 0.3±0.12 and 0.3±0.09 litres per day) goats. There was significant difference (P ˂ 0.05) of genotypes on milk fat, milk magnesium and sodium contents among Nguni, Boer and Non-descript goats. Lactation stages had a significant effect (P ˂ 0.05) on some milk compositions (fat, protein, lactose and solid non-fat) and mineral profiles (Ca, Mg, Na, K, and Fe) of Nguni goats. Lactation stages had a significant effect (P ˂ 0.05) on fat, protein, lactose and solid non-fat content and mineral profiles (Ca, Mg, Na, K, and Fe) of Nguni goats. Milk protein content of Nguni goat was positively correlated to milk fat but, not in Boer and Non-descript goats. Milk quality parameters from the three goat genotypes possessed relatively moderate milk compositions and mineral profiles which is comparable to some exotic goat breeds. Nguni kids had higher mean weights (7.36 kg, 11.85 kg and 13.72 kg) than the Boer kids (5.20 kg, 7.18 kg and 10.20 kg) and the Non-descript goat kids (5.23 kg, 6.19 kg and 8.01 kg) at weeks 4, 6 and 8 after parturition, respectively. In terms of height at withers, the Nguni kids had higher mean values in heights (41.92 cm, 44.71 cm, 49.38 cm and 55.75 cm) than the Boer kids (35.67 cm, 37.14 cm, 42.40 and 44.20 cm) and the Non-descript kids (36.38 cm, 40.20 cm, 41.14 cm and 43.50 cm) at week 2, 4, 6 and 8 after parturition, respectively. Conversely, there was a positive correlation (P ˂ 0.05) between body lengths and live weights of Nguni goats and not in Boer and Non-descript goats. It was concluded from this study that, the indigenous Nguni, Boer and Non-descript pregnant goats were managed in poor conditions by communal farmers and the perceived causes of mortality of pregnant goats among others include poor feed, diseases and predators. In addition, the Nguni goats had higher mean values in some haematological parameters (red cell counts and haemoglobin) and serum biochemical profiles (glucose, sodium, urea and creatine kinase) than Boer and Non-descript goats during the periods of investigation. Nguni goats also produced more milk at the early and late stages of lactation compared to the Boer and Non-descript goats. The Non-descript goats had a higher mean value of milk fat compared to Nguni and Boer goats. Likewise, the Boer goats were observed to have higher mean value of milk magnesium and sodium content compared to Nguni and Non-descript goats. In terms of body weights and linear body measurments, the Nguni goat kids were superior compared to Boer and Non-descript goats.
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Moringa oleifera leaf powder as a functional antioxidant additive in pork droewors
- Authors: Mukumbo, Felicitas Esnart
- Date: 2016
- Subjects: Antioxidants , Moringa oleifera , Pork -- Quality
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/15354 , vital:40400
- Description: The study investigated the effect of Moringa oleifera leaf powder (MLP) on physico-chemical characteristics, antioxidant activity, antioxidant compound content and lipid oxidation in pork droëwors. Firstly, the physico-chemical properties (proximate composition, salt content, water activity (aw), pH) of commercially produced droëwors from different types of meat (beef, game, ostrich) were determined. In the second experiment beef and pork droëwors with similar fat content were produced. Physico-chemical properties and lipid oxidation (thiobarbituric reactive substances (TBARS)) during processing and 26 days of storage at 25 °C and 50percent relative humidity (RH) were measured. In the third experiment, antioxidant compounds (Total Phenolic Compounds (TPC), α-tocopherol, β-carotene) in MLP were quantified. Thereafter, 4 treatments of pork droëwors were produced, with MLP included at 0, 0.5, 1 and 2 g/ 100 g. Physico-chemical properties and TBARS were measured at intervals during drying (0, 1.5, 5.75, 27.25, 72 h) and after 7 days of storage under ambient conditions. Antioxidant activity (ferric reducing antioxidant power (FRAP)), TBARS, α- and γ-tocopherol, and β-carotene contents were measured. In the fourth experiment, three batches of droëwors were produced (C: no antioxidant, M0.75: 0.75 g/ 100 g MLP, VE: 15 mg/ kg α-tocopherol oil) and stored at 25 °C and 50percent relative humidity for 112 days. Drying kinetics and α-tocopherol contents of pork droëwors after drying were measured and the physico-chemical properties and TBARS were followed during storage. Results showed no differences (P > 0.05) in the physico-chemical characteristics of beef, game meat and ostrich droëwors; containing on average 25.8 ± 1.25 g/100 g moisture, 42.0 ± 0.10 g/100 g protein, 32.0 ± 1.68 g/100 g fat, 6.2 ± 0.13 g/100 g ash and 4.2 ± 0.10 g/100 g salt; with aw and pH of 0.79 ± 0.015 and 5.3 ± 0.05, respectively. During processing and storage, TBARS were higher (P < 0.05) in pork droëwors (maximum 3.83 mg MDA/kg DM) than in beef (maximum 0.99 mg MDA/kg DM). Moringa oleifera leaf powder contained high levels of TPC (7.5 ± 0.2 mg gallic acid eq/g) and substantial levels of α-tocopherol (76.7 ± 1.9 mg/100 g) and β-carotene (23.2 ± 2.8 mg/100 g). The FRAP, α-tocopherol and β-carotene content of pork droëwors increased (P < 0.05) proportionally with increasing levels of MLP inclusion. Lipid oxidation occurred more rapidly (P < 0.05) when MLP was not added and was similar (P > 0.05) for all MLP treatments. There was no significant effect of the inclusion of 0.75 g/100 g MLP on the drying curves and physico-chemical characteristics of the droëwors. The α-tocopherol content was higher (P < 0.05) and TBARS during storage were lower (P > 0.05) with MLP addition. The results of the current study give an overview of the composition of commercial droëwors and showed higher susceptibility to lipid oxidation in pork droëwors. Moringa oleifera leaf powder exhibited antioxidant activity in pork droëwors, inhibited lipid oxidation and increased the content of α-tocopherol in the product. It can be concluded that MLP could be used as a functional antioxidant additive in pork droëwors.
- Full Text:
- Authors: Mukumbo, Felicitas Esnart
- Date: 2016
- Subjects: Antioxidants , Moringa oleifera , Pork -- Quality
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: http://hdl.handle.net/10353/15354 , vital:40400
- Description: The study investigated the effect of Moringa oleifera leaf powder (MLP) on physico-chemical characteristics, antioxidant activity, antioxidant compound content and lipid oxidation in pork droëwors. Firstly, the physico-chemical properties (proximate composition, salt content, water activity (aw), pH) of commercially produced droëwors from different types of meat (beef, game, ostrich) were determined. In the second experiment beef and pork droëwors with similar fat content were produced. Physico-chemical properties and lipid oxidation (thiobarbituric reactive substances (TBARS)) during processing and 26 days of storage at 25 °C and 50percent relative humidity (RH) were measured. In the third experiment, antioxidant compounds (Total Phenolic Compounds (TPC), α-tocopherol, β-carotene) in MLP were quantified. Thereafter, 4 treatments of pork droëwors were produced, with MLP included at 0, 0.5, 1 and 2 g/ 100 g. Physico-chemical properties and TBARS were measured at intervals during drying (0, 1.5, 5.75, 27.25, 72 h) and after 7 days of storage under ambient conditions. Antioxidant activity (ferric reducing antioxidant power (FRAP)), TBARS, α- and γ-tocopherol, and β-carotene contents were measured. In the fourth experiment, three batches of droëwors were produced (C: no antioxidant, M0.75: 0.75 g/ 100 g MLP, VE: 15 mg/ kg α-tocopherol oil) and stored at 25 °C and 50percent relative humidity for 112 days. Drying kinetics and α-tocopherol contents of pork droëwors after drying were measured and the physico-chemical properties and TBARS were followed during storage. Results showed no differences (P > 0.05) in the physico-chemical characteristics of beef, game meat and ostrich droëwors; containing on average 25.8 ± 1.25 g/100 g moisture, 42.0 ± 0.10 g/100 g protein, 32.0 ± 1.68 g/100 g fat, 6.2 ± 0.13 g/100 g ash and 4.2 ± 0.10 g/100 g salt; with aw and pH of 0.79 ± 0.015 and 5.3 ± 0.05, respectively. During processing and storage, TBARS were higher (P < 0.05) in pork droëwors (maximum 3.83 mg MDA/kg DM) than in beef (maximum 0.99 mg MDA/kg DM). Moringa oleifera leaf powder contained high levels of TPC (7.5 ± 0.2 mg gallic acid eq/g) and substantial levels of α-tocopherol (76.7 ± 1.9 mg/100 g) and β-carotene (23.2 ± 2.8 mg/100 g). The FRAP, α-tocopherol and β-carotene content of pork droëwors increased (P < 0.05) proportionally with increasing levels of MLP inclusion. Lipid oxidation occurred more rapidly (P < 0.05) when MLP was not added and was similar (P > 0.05) for all MLP treatments. There was no significant effect of the inclusion of 0.75 g/100 g MLP on the drying curves and physico-chemical characteristics of the droëwors. The α-tocopherol content was higher (P < 0.05) and TBARS during storage were lower (P > 0.05) with MLP addition. The results of the current study give an overview of the composition of commercial droëwors and showed higher susceptibility to lipid oxidation in pork droëwors. Moringa oleifera leaf powder exhibited antioxidant activity in pork droëwors, inhibited lipid oxidation and increased the content of α-tocopherol in the product. It can be concluded that MLP could be used as a functional antioxidant additive in pork droëwors.
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Determination and validation of medicinal plants used by farmers to control internal and external parasites in goats in the Eastern Cape Province, South Africa
- Authors: Sanhokwe, Marcia
- Date: 2015
- Subjects: Medicinal plants -- South Africa -- Eastern Cape Goats -- Parasites -- Control
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/2249 , vital:27718
- Description: The broad objective of the study was to determine and validate medicinal plants used by resource-limited farmers to control internal and external parasites in goats in the Eastern Cape Province, South Africa. A survey was conducted among 50 farmers and three herbalists to determine medicinal plants used to control parasites in goats. The survey revealed nine plant species belonging to eight families that were used. Among the identified plant species, Aloe ferox, Acokanthera oppositifolia and Elephantorrhiza elephantina were the plants having the highest Fidelity Level for their use, each scored 100.00 percent, followed by Albuca setosa (83.33 percent). These plants were then selected for validation studies. Gas-Chromatography-Mass-Spectrometry (GC-MS) revealed 7, 33, 26 and 32 bioactive phytochemicals in A. ferox, E. elephantina, A. oppositifolia and A. setosa, respectively. Terpenes and fatty acids were present, oxygenated terpenes being the most abundant hydrocarbons present in all the four plant species. The effect of acetone, methanol and ethanol extracts of leaves of Aloe ferox and Acokanthera oppositifolia on tick repellency and acaricidal activity were investigated on blood engorged Ambylomma hebraeum and Rhipicephalus decoloratus ticks at concentration 15, 30 and 50 percent. The 30 and 50 percent acetone extract of A. ferox and Dazzel dip had the highest acaricidal properties of 100 percent. The 50 percent methanol extract of A. oppositifolia and 50 percent acetone extract of A. ferox had the highest repellency activity of 89 percent and 85.33 percent, respectively. Results from this study revealed that the efficacy of medicinal plants used by farmers to control ticks vary with the type of solvent used for extracting the bioactive compounds. Furthermore, it revealed that Aloe ferox and A. opppositifolia plant extracts possess repellent and acaricidal activities. In a study to investigate the anthelminthic effect of crude extracts of Elephantorrhiza elephantina and Albuca setosa plants, significant anthelminthic effect on nematodes was observed in both plants. In this study, all E. elephantina and A. setosa extracts caused paralysis and mortality. Methanol was the most effective solvent in extracting bioactive compounds and methanol extract showed the best anthelminthic effects among the crude extracts investigated in both plants. The least time taken for the worms to be paralysed was 8.33 mins and 14.33mins in 100mg/ml methanol extracts of E. elephantina and A. setosa, resepectively. Methanol extract of E. elephantina and A. setosa (100mg/ml) had the highest anthelminthic activity and mortality was recorded after 18mins and 20mins, respectively. Results from this study revealed that these two plants possess anthelminthic activities. The study revealed that resource-limited farmers use medicinal plants to control internal and external parasites in goats. Gas-Chromatography-Mass-Spectrometry analysis showed that these plants contain bioactive compounds that have a potential in controlling parasites. Validation studies showed that A. ferox and A. oppositifolia possess repellent and acaricidal activities whereas A. setosa and E. elephantina possess anthelminthic activities.
- Full Text:
- Authors: Sanhokwe, Marcia
- Date: 2015
- Subjects: Medicinal plants -- South Africa -- Eastern Cape Goats -- Parasites -- Control
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/2249 , vital:27718
- Description: The broad objective of the study was to determine and validate medicinal plants used by resource-limited farmers to control internal and external parasites in goats in the Eastern Cape Province, South Africa. A survey was conducted among 50 farmers and three herbalists to determine medicinal plants used to control parasites in goats. The survey revealed nine plant species belonging to eight families that were used. Among the identified plant species, Aloe ferox, Acokanthera oppositifolia and Elephantorrhiza elephantina were the plants having the highest Fidelity Level for their use, each scored 100.00 percent, followed by Albuca setosa (83.33 percent). These plants were then selected for validation studies. Gas-Chromatography-Mass-Spectrometry (GC-MS) revealed 7, 33, 26 and 32 bioactive phytochemicals in A. ferox, E. elephantina, A. oppositifolia and A. setosa, respectively. Terpenes and fatty acids were present, oxygenated terpenes being the most abundant hydrocarbons present in all the four plant species. The effect of acetone, methanol and ethanol extracts of leaves of Aloe ferox and Acokanthera oppositifolia on tick repellency and acaricidal activity were investigated on blood engorged Ambylomma hebraeum and Rhipicephalus decoloratus ticks at concentration 15, 30 and 50 percent. The 30 and 50 percent acetone extract of A. ferox and Dazzel dip had the highest acaricidal properties of 100 percent. The 50 percent methanol extract of A. oppositifolia and 50 percent acetone extract of A. ferox had the highest repellency activity of 89 percent and 85.33 percent, respectively. Results from this study revealed that the efficacy of medicinal plants used by farmers to control ticks vary with the type of solvent used for extracting the bioactive compounds. Furthermore, it revealed that Aloe ferox and A. opppositifolia plant extracts possess repellent and acaricidal activities. In a study to investigate the anthelminthic effect of crude extracts of Elephantorrhiza elephantina and Albuca setosa plants, significant anthelminthic effect on nematodes was observed in both plants. In this study, all E. elephantina and A. setosa extracts caused paralysis and mortality. Methanol was the most effective solvent in extracting bioactive compounds and methanol extract showed the best anthelminthic effects among the crude extracts investigated in both plants. The least time taken for the worms to be paralysed was 8.33 mins and 14.33mins in 100mg/ml methanol extracts of E. elephantina and A. setosa, resepectively. Methanol extract of E. elephantina and A. setosa (100mg/ml) had the highest anthelminthic activity and mortality was recorded after 18mins and 20mins, respectively. Results from this study revealed that these two plants possess anthelminthic activities. The study revealed that resource-limited farmers use medicinal plants to control internal and external parasites in goats. Gas-Chromatography-Mass-Spectrometry analysis showed that these plants contain bioactive compounds that have a potential in controlling parasites. Validation studies showed that A. ferox and A. oppositifolia possess repellent and acaricidal activities whereas A. setosa and E. elephantina possess anthelminthic activities.
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Effect of Tenebrio molitor larvae as a protein source on growth performance, carcass yield and meat quality of broiler chickens
- Authors: Mngqi, Sinethemba Census
- Date: 2015
- Subjects: Broilers (Chickens) Chickens -- Feeding and feeds Meat -- Quality
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/2622 , vital:27944
- Description: This study was conducted to assess the effect of including Tenebrio molitor larvae (T. molitor L) as a protein source in different diets on broiler performance, carcass characteristics and meat quality. A total of 144 day-old Cobb-500 chicks were randomly allocated into three treatment groups, each was allocated 16 birds and reared in 9 identical pens. Experimental diets used were as follows: T1 Control (no T. molitor L inclusion); T2 and T3 contained levels of T. molitor L at 5 percent and 10 percent of dry matter (DM) intake, respectively. Body weights (BW), average daily gain (ADG), feed intake (FI), and Feed conversion ratio (FCR) were measured for the 1st experimental chapter. For the second experimental chapter; live weights (LW) of broilers were recorded before slaughter and thereafter carcass weights (CW), meat yield (weights of breast, thigh, drumstick and wing) were recorded. The dressing percentage (DP percent) was also calculated. Breast muscles were sampled for meat pH and colour measurements. The LW of birds from T1 (0 percent T. molitor L) were significantly different (P<0.05) from both T2 (5 percent T. molitor L) and T3 (10 percent T. molitor L) which were similar to each other, with T2 exhibiting the highest live weights (2166g) and the control treatment exhibiting the lowest live weights (2018.3g). In CW, T1 was significantly different (P<0.05) from T2 while it was similar (P>0.05) to T3. The dressing percent of T1 was significantly different (P<0.05) from T2 and T3 which were similar to each other, with T2 having the highest dressing percentage (78, 2 percent) and T1 having the lowest DP percent (66 percent). The breasts in T2 were significantly higher and different (P<0.05) from both T1 and T3 which were similar to each other. The drumsticks in T3 were significantly different (P<0.05) from T1 while they were similar to T2 with values with T2 having highest values. After 45 minutes of slaughter, a significant difference (P<0.05) was observed in L⃰ among all treatments. In redness (a⃰), T3 was significantly different from T1 but was similar to T2 and all treatments in this study exhibited a darker red meat, with T3 muscles exhibiting darker red colour than the other treatments. Similar results were observed in yellowness (b⃰), where the breast muscles from T3 were more yellow than the other treatments. After 24 hours of slaughter, T2 L⃰ values were significantly different (P<0.05) from both T1 and T3 which were similar to each other. It was also found that the broiler chickens given diet with no T. molitor L inclusion (T1) had lower values of BW, FI, ADG and FCR throughout the experiment than those that were in T2 and T3 with 5 percent and 10 percent T. molitor L inclusion levels, respectively. However, it was also found that although broilers with 5 percent T. molitor L inclusion (T2) in their diet had high ABW and ADG than the broilers with 10 percent T. molitor L inclusion (T3), the T3 birds compared favourably to T2 birds as they required low feed intake to reach the same slaughter weight due to high FCR. It was, therefore, concluded that T. molitor L meal can be incorporated into the diets of broilers to produce heavy birds either at 5 or 10 percent. However, although 5 percent T. molitor L inclusion yields heavier carcasses, the 10 percent T. molitor L inclusion compared favourably to 5 percent inclusion since it required low feed intake to reach the same slaughter weights and there were slight differences on meat quality attributes between the two treatments.Thus T. molitor L at 10 percent inclusion levels was the best inclusion level to enhance broiler growth performance, carcass yield, meat yield and meat quality.
- Full Text:
- Authors: Mngqi, Sinethemba Census
- Date: 2015
- Subjects: Broilers (Chickens) Chickens -- Feeding and feeds Meat -- Quality
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/2622 , vital:27944
- Description: This study was conducted to assess the effect of including Tenebrio molitor larvae (T. molitor L) as a protein source in different diets on broiler performance, carcass characteristics and meat quality. A total of 144 day-old Cobb-500 chicks were randomly allocated into three treatment groups, each was allocated 16 birds and reared in 9 identical pens. Experimental diets used were as follows: T1 Control (no T. molitor L inclusion); T2 and T3 contained levels of T. molitor L at 5 percent and 10 percent of dry matter (DM) intake, respectively. Body weights (BW), average daily gain (ADG), feed intake (FI), and Feed conversion ratio (FCR) were measured for the 1st experimental chapter. For the second experimental chapter; live weights (LW) of broilers were recorded before slaughter and thereafter carcass weights (CW), meat yield (weights of breast, thigh, drumstick and wing) were recorded. The dressing percentage (DP percent) was also calculated. Breast muscles were sampled for meat pH and colour measurements. The LW of birds from T1 (0 percent T. molitor L) were significantly different (P<0.05) from both T2 (5 percent T. molitor L) and T3 (10 percent T. molitor L) which were similar to each other, with T2 exhibiting the highest live weights (2166g) and the control treatment exhibiting the lowest live weights (2018.3g). In CW, T1 was significantly different (P<0.05) from T2 while it was similar (P>0.05) to T3. The dressing percent of T1 was significantly different (P<0.05) from T2 and T3 which were similar to each other, with T2 having the highest dressing percentage (78, 2 percent) and T1 having the lowest DP percent (66 percent). The breasts in T2 were significantly higher and different (P<0.05) from both T1 and T3 which were similar to each other. The drumsticks in T3 were significantly different (P<0.05) from T1 while they were similar to T2 with values with T2 having highest values. After 45 minutes of slaughter, a significant difference (P<0.05) was observed in L⃰ among all treatments. In redness (a⃰), T3 was significantly different from T1 but was similar to T2 and all treatments in this study exhibited a darker red meat, with T3 muscles exhibiting darker red colour than the other treatments. Similar results were observed in yellowness (b⃰), where the breast muscles from T3 were more yellow than the other treatments. After 24 hours of slaughter, T2 L⃰ values were significantly different (P<0.05) from both T1 and T3 which were similar to each other. It was also found that the broiler chickens given diet with no T. molitor L inclusion (T1) had lower values of BW, FI, ADG and FCR throughout the experiment than those that were in T2 and T3 with 5 percent and 10 percent T. molitor L inclusion levels, respectively. However, it was also found that although broilers with 5 percent T. molitor L inclusion (T2) in their diet had high ABW and ADG than the broilers with 10 percent T. molitor L inclusion (T3), the T3 birds compared favourably to T2 birds as they required low feed intake to reach the same slaughter weight due to high FCR. It was, therefore, concluded that T. molitor L meal can be incorporated into the diets of broilers to produce heavy birds either at 5 or 10 percent. However, although 5 percent T. molitor L inclusion yields heavier carcasses, the 10 percent T. molitor L inclusion compared favourably to 5 percent inclusion since it required low feed intake to reach the same slaughter weights and there were slight differences on meat quality attributes between the two treatments.Thus T. molitor L at 10 percent inclusion levels was the best inclusion level to enhance broiler growth performance, carcass yield, meat yield and meat quality.
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Effects of natural antioxidants and thermal treatment on quality of meat from Bonsmara and non-descripts cattle
- Authors: Falowo, Andrew Bamidele
- Date: 2015
- Subjects: Meat -- Preservation Antioxidants Meat -- Microbiology
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/2589 , vital:27906
- Description: The broad objective of this study was to determine the effects of natural antioxidants and thermal treatment on quality of meat from Bonsmara and non-descript cattle. A survey was conducted among 222 consumers in Alice (Fort Hare University community), Eastern Cape Province to determine the level of their awareness on application of antioxidants as preservatives in meat and meat products during storage. Representative samples of Muscularis longissimuss thoracis et lumborum and liver were collected from each carcass of Bonsmara (n=40) and non-descript (n=40) cattle reared on natural pasture to determine the effect of natural antioxidants and thermal treatment on their quality. The results from the survey revealed that 51.35 percent of the respondents had not heard about the use of antioxidant as preservatives in meat products. However, among the remaining respondents (48.65 percent) that were aware of antioxidant and its use as preservative, about 19 percent knew of natural antioxidants, 35 percent synthetic antioxidants while 46 percent had knowledge of both. The results further revealed that the majority of the respondents (82 percent) that had knowledge of natural antioxidants were concerned about the use of synthetic antioxidants in meat and meat products due to their health consequences. The in vitro antioxidant and antibacterial analyses of Bidens pilosa and Moringa oleifera leaf extracts revealed that they contain rich bioactive compounds. Furthermore, the addition of leaf extracts from Moringa oleifera (ML, 0.05 and 0.1 percent w/w) and Biden pilosa (BP, 0.05 and 0.1 percent w/w) to ground raw beef as a natural antioxidant were found to improve the physicochemical, oxidative stability and microbiological qualities of meat compared to the control (meat without extract) and BHT treatment (0.02 percent w/w) during 6 days storage at 40 C. Cattle breed did not have much effect on colour parameters. However, the overall pH of ground beef treated with extracts showed lower values than control and BHT treated beef. Also, ground beef samples containing extracts exhibited (P < 0.05) better colour stability, especially higher redness (a* values), than the control. The formation of TBARS in beef samples treated with extracts was significantly (P < 0.05) lower than the control and BHT treatment. The antibacterial assay of the extracts revealed an appreciable broad spectrum activity against the tested bacteria and microbial counts in ground beef samples compared to control and BHT group. Ground beef treated with plant extracts exhibited lower microbial and lactic acid bacterial counts (P < 0.05) at day 0 and 3 than control samples. Moreover, it was observed that application of sous vides thermal method did not significantly affect the fatty acids and mineral loss in beef and liver across the treatments. However, the total concentration of MUFA was lower in raw liver (20.11±2.38 - 21.08±1.23 percent) than in beef (40.22±1.90 - 42.53±1.29 percent), while total PUFA content were higher in liver (30.73±2.60 - 31.11±1.19 percent) than in beef samples (10.13±3.36 - 11.02±2.74 percent) (p < 0.05). The results also revealed that liver samples from Bonsmara and non-descript cattle had a higher percentage of intramuscular fat content of 4.67 ± 0.53 percent and 4.44 ± 0.53 percent respectively, and fat free dry matter of 27.51 ± 1.05 percent and 25.73 ± 1.05 percent, respectively, than the beef samples (p < 0.05). The concentrations of Mg (52.80±0.22 - 53.70±0.02mg/100g) and Zn (8.90±0.15 - 19.60±0.15mg/100g) were higher in beef than liver samples. The level of Ca (17.00±0.17 - 17.50 ± 0.17mg/100g) in liver was higher than that of beef samples. It was concluded that most consumers preferred the use of natural antioxidants in meat products than synthetic antioxidants due to their health risk. The effectiveness of M. oleifera and B. pilosa leaf extracts on meat quality also revealed that these plants are promising candidates as natural preservatives and their application should be considered in the meat industry. Lastly, findings from this study showed that application of the sous vide technique could protect meat products from nutritional loss during thermal treatment.
- Full Text:
- Authors: Falowo, Andrew Bamidele
- Date: 2015
- Subjects: Meat -- Preservation Antioxidants Meat -- Microbiology
- Language: English
- Type: Thesis , Doctoral , DPhil
- Identifier: http://hdl.handle.net/10353/2589 , vital:27906
- Description: The broad objective of this study was to determine the effects of natural antioxidants and thermal treatment on quality of meat from Bonsmara and non-descript cattle. A survey was conducted among 222 consumers in Alice (Fort Hare University community), Eastern Cape Province to determine the level of their awareness on application of antioxidants as preservatives in meat and meat products during storage. Representative samples of Muscularis longissimuss thoracis et lumborum and liver were collected from each carcass of Bonsmara (n=40) and non-descript (n=40) cattle reared on natural pasture to determine the effect of natural antioxidants and thermal treatment on their quality. The results from the survey revealed that 51.35 percent of the respondents had not heard about the use of antioxidant as preservatives in meat products. However, among the remaining respondents (48.65 percent) that were aware of antioxidant and its use as preservative, about 19 percent knew of natural antioxidants, 35 percent synthetic antioxidants while 46 percent had knowledge of both. The results further revealed that the majority of the respondents (82 percent) that had knowledge of natural antioxidants were concerned about the use of synthetic antioxidants in meat and meat products due to their health consequences. The in vitro antioxidant and antibacterial analyses of Bidens pilosa and Moringa oleifera leaf extracts revealed that they contain rich bioactive compounds. Furthermore, the addition of leaf extracts from Moringa oleifera (ML, 0.05 and 0.1 percent w/w) and Biden pilosa (BP, 0.05 and 0.1 percent w/w) to ground raw beef as a natural antioxidant were found to improve the physicochemical, oxidative stability and microbiological qualities of meat compared to the control (meat without extract) and BHT treatment (0.02 percent w/w) during 6 days storage at 40 C. Cattle breed did not have much effect on colour parameters. However, the overall pH of ground beef treated with extracts showed lower values than control and BHT treated beef. Also, ground beef samples containing extracts exhibited (P < 0.05) better colour stability, especially higher redness (a* values), than the control. The formation of TBARS in beef samples treated with extracts was significantly (P < 0.05) lower than the control and BHT treatment. The antibacterial assay of the extracts revealed an appreciable broad spectrum activity against the tested bacteria and microbial counts in ground beef samples compared to control and BHT group. Ground beef treated with plant extracts exhibited lower microbial and lactic acid bacterial counts (P < 0.05) at day 0 and 3 than control samples. Moreover, it was observed that application of sous vides thermal method did not significantly affect the fatty acids and mineral loss in beef and liver across the treatments. However, the total concentration of MUFA was lower in raw liver (20.11±2.38 - 21.08±1.23 percent) than in beef (40.22±1.90 - 42.53±1.29 percent), while total PUFA content were higher in liver (30.73±2.60 - 31.11±1.19 percent) than in beef samples (10.13±3.36 - 11.02±2.74 percent) (p < 0.05). The results also revealed that liver samples from Bonsmara and non-descript cattle had a higher percentage of intramuscular fat content of 4.67 ± 0.53 percent and 4.44 ± 0.53 percent respectively, and fat free dry matter of 27.51 ± 1.05 percent and 25.73 ± 1.05 percent, respectively, than the beef samples (p < 0.05). The concentrations of Mg (52.80±0.22 - 53.70±0.02mg/100g) and Zn (8.90±0.15 - 19.60±0.15mg/100g) were higher in beef than liver samples. The level of Ca (17.00±0.17 - 17.50 ± 0.17mg/100g) in liver was higher than that of beef samples. It was concluded that most consumers preferred the use of natural antioxidants in meat products than synthetic antioxidants due to their health risk. The effectiveness of M. oleifera and B. pilosa leaf extracts on meat quality also revealed that these plants are promising candidates as natural preservatives and their application should be considered in the meat industry. Lastly, findings from this study showed that application of the sous vide technique could protect meat products from nutritional loss during thermal treatment.
- Full Text:
Glycolytic potential and meat quality from dorper and merino sheep slaughtered at a commercial abattoir
- Authors: Stempa, Thuthuzelwa
- Date: 2015
- Subjects: Slaughtering and slaughter-houses Meat -- Quality
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/15310 , vital:40361
- Description: The objective of the study was to determine glycolytic potential and meat quality from Dorper and Merino sheep of both sexes slaughtered at a commercial abattoir. Dorper (n=52) and Merino (n= 48) breeds aged eight years, consisting of 50 intact rams and 50 non-pregnant ewes were used in the study. The sheep used in the study were reared, transported and lairised under identical conditions. Blood samples were collected at exsanguination for the measurement of glucose, lactate and cortisol levels. Samples were also collected from the Muscularis longmissius thoracis et lumborum (LTL) for the measurement glycogen, lactate levels, pH decline and colour. Correlations amongst blood stress indicators, muscle metabolites and meat quality attributes were also determined. Sex and breed had no effect on muscle glycolytic potential, glycogen and lactate levels from Dorper and Merino sheep of both sexes at the abattoir. Although sex and breed had an effect on pre-slaughter stress indicators (lactate and cortisol) collected at exsanguination. Ewes had higher levels of blood lactate (7.4 3 ± 0.49 mmol/L) and cortisol (293.92 ± 14.32 nmol/L) than the rams which had (5.19 ± 0.49 mmol/L) and (179.50 ± 14.32 nmol/L) lactate and cortisol levels, respectively. Furthermore, higher levels of lactate were observed in Dorper (7.54 ± 0.42 mmol/L) compared to the Merino sheep (4.97 ± 0.49 mmol/L). Meat pH decline and colour were also significantly affected by sex and breed. Ewes had higher levels of at pH45 minutes post slaughter (7.05 ± 0.04), pH3 hours (6.45 ± 0.04) , pH24 hours (6.00 ± 0.03), a* (14.31 ± 0.33) , b* (8.84 ± 0.29), H* (31.47 ± 0.73) and C* (16.75 ± 0.24) compared to the rams which had pH45 minutes (6.44 ± 0.04), pH3 hours (6.12 ± 0.04), pH24 hours (5.88 ± 0.03), a* (12.25 ± 0.33), b* (7.00 ± 0.29), H* (29.36 ± 0.73) and C* (14.15 ± 0.42) values. Moreover, Merino sheep had higher levels of L* (38.17 ± 0.48) and H* (31.59 ± 0.74) compared to the Dorper which had (36.39 ± 0.46) and (29.33 ± 0.71) L* and H* values, respectively. Blood cortisol was also positively correlated (P < 0.05) to glucose (r = 0.27), lactate (r = 0.37) but was negatively correlated (P < 0.001) to meat lightness (r = -0.44). Furthermore, blood cortisol was positively correlated (P < 0.001) to pH45 (r = 0.34), pH24 (r =0.22), meat yellowness (r = 0.24) and chroma (r = 0.37), but was negatively correlated to meat lightness (r = -0.47). Glycolytic potential was positively correlated (P < 0.001) to muscle glycogen levels (r = 0.66) and muscle lactate (r = 0.71).
- Full Text:
- Authors: Stempa, Thuthuzelwa
- Date: 2015
- Subjects: Slaughtering and slaughter-houses Meat -- Quality
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/15310 , vital:40361
- Description: The objective of the study was to determine glycolytic potential and meat quality from Dorper and Merino sheep of both sexes slaughtered at a commercial abattoir. Dorper (n=52) and Merino (n= 48) breeds aged eight years, consisting of 50 intact rams and 50 non-pregnant ewes were used in the study. The sheep used in the study were reared, transported and lairised under identical conditions. Blood samples were collected at exsanguination for the measurement of glucose, lactate and cortisol levels. Samples were also collected from the Muscularis longmissius thoracis et lumborum (LTL) for the measurement glycogen, lactate levels, pH decline and colour. Correlations amongst blood stress indicators, muscle metabolites and meat quality attributes were also determined. Sex and breed had no effect on muscle glycolytic potential, glycogen and lactate levels from Dorper and Merino sheep of both sexes at the abattoir. Although sex and breed had an effect on pre-slaughter stress indicators (lactate and cortisol) collected at exsanguination. Ewes had higher levels of blood lactate (7.4 3 ± 0.49 mmol/L) and cortisol (293.92 ± 14.32 nmol/L) than the rams which had (5.19 ± 0.49 mmol/L) and (179.50 ± 14.32 nmol/L) lactate and cortisol levels, respectively. Furthermore, higher levels of lactate were observed in Dorper (7.54 ± 0.42 mmol/L) compared to the Merino sheep (4.97 ± 0.49 mmol/L). Meat pH decline and colour were also significantly affected by sex and breed. Ewes had higher levels of at pH45 minutes post slaughter (7.05 ± 0.04), pH3 hours (6.45 ± 0.04) , pH24 hours (6.00 ± 0.03), a* (14.31 ± 0.33) , b* (8.84 ± 0.29), H* (31.47 ± 0.73) and C* (16.75 ± 0.24) compared to the rams which had pH45 minutes (6.44 ± 0.04), pH3 hours (6.12 ± 0.04), pH24 hours (5.88 ± 0.03), a* (12.25 ± 0.33), b* (7.00 ± 0.29), H* (29.36 ± 0.73) and C* (14.15 ± 0.42) values. Moreover, Merino sheep had higher levels of L* (38.17 ± 0.48) and H* (31.59 ± 0.74) compared to the Dorper which had (36.39 ± 0.46) and (29.33 ± 0.71) L* and H* values, respectively. Blood cortisol was also positively correlated (P < 0.05) to glucose (r = 0.27), lactate (r = 0.37) but was negatively correlated (P < 0.001) to meat lightness (r = -0.44). Furthermore, blood cortisol was positively correlated (P < 0.001) to pH45 (r = 0.34), pH24 (r =0.22), meat yellowness (r = 0.24) and chroma (r = 0.37), but was negatively correlated to meat lightness (r = -0.47). Glycolytic potential was positively correlated (P < 0.001) to muscle glycogen levels (r = 0.66) and muscle lactate (r = 0.71).
- Full Text:
Microbiological analyses of beef slaughtering process and meat safety knowledge of handlers at selected high and low thoughput abattoirs
- Authors: Nyamakwere, Faith
- Date: 2015
- Subjects: Slaughtering and slaughter-houses -- South Africa -- Eastern Cape Meat industry and trade -- Quality control Beef -- Quality -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/2238 , vital:27712
- Description: The objective of the study was to evaluate meat hygiene practices among meat handlers and microbiological analysis of beef carcasses, slaughtermen hands, equipment and water from low throughput (LTA) and high throughput (HTA) abattoirs in the Eastern Cape Province of South Africa. In stage one of the study, the level of knowledge, practices and attitudes towards meat safety and personal hygiene of slaughtermen were assessed. Forty workers directly involve in beef cattle slaughtering process were surveyed. Data were collected using a structured questionnaire, it contained questions on some of the most important meat safety cues such as knowledge, attitudes, personal hygiene and handling practices. Cross tabulation and Chi-square Test of Association were performed to examine the relationships between the demographic information and the knowledge regarding meat safety using the Statistical Package for Social Sciences (SPSS) version 22. Overall, a significant adherence to basic hygiene practices and a satisfactory level of knowledge were observed. Workers from a HTA yielded comparatively better statistically significant scores. Moreover, knowledge and practices of respondents were significantly associated (P<0.05) due to educational level and professional training. The second stage of the study involved evaluating the level to which cattle carcass, equipment, slaughtermen hands and water were contaminated with Enterobacteriaceae, Salmonella, Escherichia coli and aerobic colony counts (ACC) at different stages during the slaughter process (skinning, evisceration, carcass slitting, inspection, washing and packing). Cattle carcasses were sampled at four sites (rump, neck, flank and brisket) from a LTA (n= 240) and HTA (n= 384) abattoirs. Using conventional biochemical tests, HTA yielded significantly (P<0.05) higher ACC (5.2 log CFU/cm2), E. coli (2.6 log CFU/cm2) and Enterobacteriaceae (2.9 log CFU/cm2) carcass mean scores than LTA after skinning and evisceration. Specific abattoir hygiene differences were noted from washed and chilled carcasses. Salmonella was not detected across all sampled slaughter process stages. In addition, the equipment had bacterial load ranging from 10 to 4 CFU/cm2 for LTA, whereas in HTA this was found to be 7 to 3 CFU/cm2. The bacterial counts for slaughtermen hands were estimated to be 15 to 8 CFU/cm2 in HTA and 10 to 5 CFU/cm2 in LTA. Overall, slaughtermen hands and equipment in the dirty area (skinning and evisceration) yielded more bacterial counts compared to those in the clean area (slitting, inspection, washing and packing) from both abattoirs. For all the sampled carcasses, equipment and slaughtermen hands, HTA yielded comparatively higher (P<0.05) bacterial counts than the LTA. Although the results showed a significant adherence to basic hygiene practices, some aspects such as routine medical examination, health certificates and professional training of slaughtermen still need to be improved. Therefore, these findings show that slaughtermen, equipment and water can be sources of contamination during the slaughter process.
- Full Text:
- Authors: Nyamakwere, Faith
- Date: 2015
- Subjects: Slaughtering and slaughter-houses -- South Africa -- Eastern Cape Meat industry and trade -- Quality control Beef -- Quality -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/2238 , vital:27712
- Description: The objective of the study was to evaluate meat hygiene practices among meat handlers and microbiological analysis of beef carcasses, slaughtermen hands, equipment and water from low throughput (LTA) and high throughput (HTA) abattoirs in the Eastern Cape Province of South Africa. In stage one of the study, the level of knowledge, practices and attitudes towards meat safety and personal hygiene of slaughtermen were assessed. Forty workers directly involve in beef cattle slaughtering process were surveyed. Data were collected using a structured questionnaire, it contained questions on some of the most important meat safety cues such as knowledge, attitudes, personal hygiene and handling practices. Cross tabulation and Chi-square Test of Association were performed to examine the relationships between the demographic information and the knowledge regarding meat safety using the Statistical Package for Social Sciences (SPSS) version 22. Overall, a significant adherence to basic hygiene practices and a satisfactory level of knowledge were observed. Workers from a HTA yielded comparatively better statistically significant scores. Moreover, knowledge and practices of respondents were significantly associated (P<0.05) due to educational level and professional training. The second stage of the study involved evaluating the level to which cattle carcass, equipment, slaughtermen hands and water were contaminated with Enterobacteriaceae, Salmonella, Escherichia coli and aerobic colony counts (ACC) at different stages during the slaughter process (skinning, evisceration, carcass slitting, inspection, washing and packing). Cattle carcasses were sampled at four sites (rump, neck, flank and brisket) from a LTA (n= 240) and HTA (n= 384) abattoirs. Using conventional biochemical tests, HTA yielded significantly (P<0.05) higher ACC (5.2 log CFU/cm2), E. coli (2.6 log CFU/cm2) and Enterobacteriaceae (2.9 log CFU/cm2) carcass mean scores than LTA after skinning and evisceration. Specific abattoir hygiene differences were noted from washed and chilled carcasses. Salmonella was not detected across all sampled slaughter process stages. In addition, the equipment had bacterial load ranging from 10 to 4 CFU/cm2 for LTA, whereas in HTA this was found to be 7 to 3 CFU/cm2. The bacterial counts for slaughtermen hands were estimated to be 15 to 8 CFU/cm2 in HTA and 10 to 5 CFU/cm2 in LTA. Overall, slaughtermen hands and equipment in the dirty area (skinning and evisceration) yielded more bacterial counts compared to those in the clean area (slitting, inspection, washing and packing) from both abattoirs. For all the sampled carcasses, equipment and slaughtermen hands, HTA yielded comparatively higher (P<0.05) bacterial counts than the LTA. Although the results showed a significant adherence to basic hygiene practices, some aspects such as routine medical examination, health certificates and professional training of slaughtermen still need to be improved. Therefore, these findings show that slaughtermen, equipment and water can be sources of contamination during the slaughter process.
- Full Text:
Primiparous and multiparous cow behaviour of friesland, jersey and cross-bred cows around calving time and during milking
- Authors: Mpisana, Zuko
- Date: 2015
- Subjects: Dairy products--Analysis Jersey cattle Milk yield
- Language: English
- Type: Thesis , Masters , Animal Science
- Identifier: http://hdl.handle.net/10353/16113 , vital:40665
- Description: The objective of the study was to determine effect of behaviour of primiparous and multiparous Friesland, Jersey and Cross-bred cows around calving time and during milking of first lactating cows in a pasture-based dairy system. The trial was conducted at the Fort Hare dairy farm. All pregnant primiparous and multiparous were kept in a maternity paddock. Five observers monitored the cows from the onset of parturition until the calf was fully expelled using digital stop watches. The behavioural responses of the cows during parturition (frequency and duration of lying, standing and walking bouts; calf licking; suckling) and milking (avoidance distance scores (ADS), entrance score, (ES), exit speed (ES), feeding score (FS), and the occurrence of stepping (STP) and kicking (KCK)) were determined on eighty consecutive days. The behavioural attributes were analysed using generalised linear model of procedure of SAS (2003). One hundred and twenty pregnant cows were used in the study, comprising of forty cows per genotype in different parities (A-primiparous, B- 2 to 4, C-5 to 6 and D-7 to 8) and kept in a maternity paddock. Five observers monitored cows from the onset of parturition until the calf was fully expelled. There were differences (P < 0.05) observed on the behavioural patterns around the time of calving. Jersey multiparous cows spent (P < 0.05) significantly most of their time (20.50±3.10) in lying position as compared to the other genotypes. The Jersey genotype also spent most (P < 0.05) of their time (48.00±0.34) in a standing position during calving period. Friesland cows spent (P < 0.05) most of their time (12.00±1.19) exhibiting either stepping or walking attributes as compared to Jersey and Crossbred cows. The Jersey genotype spent significantly (P < 0.05) more time (123.00±10.43) expelling calves compared to the other genotypes. Crossbred cows had the highest avoidance distance (14percent) scores compared to other genotypes and the Friesland cows had the lowest distance scores. The occurrence of kicking was significantly (P < 0.05) higher for the Friesland cows (57.3percent) compared to Jersey (23.2percent) and Crossbred cows (19.6percent). The Friesland cows had the highest (P < 0.05) frequency (36.2percent) feeding score compared to Jersey and Crossbred cows. The Jersey cows had the highest (60.2percent) exit speed compared to other genotypes. The occurrence of stepping was higher for the Friesland cows (53.9percent). The Friesland cows had the highest (P < 0.05) daily milk yield compared to Jersey and Crossbred cows. The present study revealed that behavioural activities of dairy cattle during parturition differed according to genotype and parity and the behavioural response of first lactating cows differ according to genotype during milking.
- Full Text:
- Authors: Mpisana, Zuko
- Date: 2015
- Subjects: Dairy products--Analysis Jersey cattle Milk yield
- Language: English
- Type: Thesis , Masters , Animal Science
- Identifier: http://hdl.handle.net/10353/16113 , vital:40665
- Description: The objective of the study was to determine effect of behaviour of primiparous and multiparous Friesland, Jersey and Cross-bred cows around calving time and during milking of first lactating cows in a pasture-based dairy system. The trial was conducted at the Fort Hare dairy farm. All pregnant primiparous and multiparous were kept in a maternity paddock. Five observers monitored the cows from the onset of parturition until the calf was fully expelled using digital stop watches. The behavioural responses of the cows during parturition (frequency and duration of lying, standing and walking bouts; calf licking; suckling) and milking (avoidance distance scores (ADS), entrance score, (ES), exit speed (ES), feeding score (FS), and the occurrence of stepping (STP) and kicking (KCK)) were determined on eighty consecutive days. The behavioural attributes were analysed using generalised linear model of procedure of SAS (2003). One hundred and twenty pregnant cows were used in the study, comprising of forty cows per genotype in different parities (A-primiparous, B- 2 to 4, C-5 to 6 and D-7 to 8) and kept in a maternity paddock. Five observers monitored cows from the onset of parturition until the calf was fully expelled. There were differences (P < 0.05) observed on the behavioural patterns around the time of calving. Jersey multiparous cows spent (P < 0.05) significantly most of their time (20.50±3.10) in lying position as compared to the other genotypes. The Jersey genotype also spent most (P < 0.05) of their time (48.00±0.34) in a standing position during calving period. Friesland cows spent (P < 0.05) most of their time (12.00±1.19) exhibiting either stepping or walking attributes as compared to Jersey and Crossbred cows. The Jersey genotype spent significantly (P < 0.05) more time (123.00±10.43) expelling calves compared to the other genotypes. Crossbred cows had the highest avoidance distance (14percent) scores compared to other genotypes and the Friesland cows had the lowest distance scores. The occurrence of kicking was significantly (P < 0.05) higher for the Friesland cows (57.3percent) compared to Jersey (23.2percent) and Crossbred cows (19.6percent). The Friesland cows had the highest (P < 0.05) frequency (36.2percent) feeding score compared to Jersey and Crossbred cows. The Jersey cows had the highest (60.2percent) exit speed compared to other genotypes. The occurrence of stepping was higher for the Friesland cows (53.9percent). The Friesland cows had the highest (P < 0.05) daily milk yield compared to Jersey and Crossbred cows. The present study revealed that behavioural activities of dairy cattle during parturition differed according to genotype and parity and the behavioural response of first lactating cows differ according to genotype during milking.
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The effect of grain and soya bean-based diets on chicken production, some egg quality traits, and the potential for allergen carryover to eggs and meat
- Authors: Dokora, Adia-En-Michelle
- Date: 2015
- Subjects: Chickens -- Nutrition Chickens --Feeding and feeds Meat -- Quality
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/2946 , vital:28192
- Description: This study determined the effect of maize-, whole wheat-, soya bean-based-diets on the growth performance, egg quality and dressing percentage of chickens, as well as the potential for soy and gluten allergen carryover to eggs and meat from chickens. Twenty 36-week-old Lorham White (LW) hens were divided into two groups and kept in individual cages until they reached 39-weeks of age, with water and feed supplied ad libitum. Ten LW hens were fed a maize/soya bean-based diet (T1) and the other ten birds were fed a maize/soya bean-based diet with a 15 percent whole wheat inclusion (T2) for a period of four weeks, with weekly individual hen weights and group feed consumption figures being recorded. After a two-week diet adaptation period, six eggs per treatment group were collected every second day from the LW hens’ to measure egg quality traits. Every third day, over a 29-day period, six eggs per treatment were collected and analysed for the presence of soy, gluten and gluten-derived peptides using allergen specific enzyme linked immunosorbent assays (ELISA) kits. For the broiler trial, a total of 160 Ross 308 mixed sex day old chicks were used in a completely randomized design. Two dietary treatments were assigned to eight cages (replicate) per treatment, with ten birds per cage. The Ross 308 broiler feeding programme consisted of three phases, starter (day 1 to day 10), grower (day 11 to day 20) and finisher (day 21 to day 28). At the beginning of the trial all chicks were fed T1 which contained a maize/soya bean-based diet for a period of 10 days and then eight cages with 10 birds per cage were randomly selected and fed the T2 diet, which contained a maize/soya bean-based diet with a 15 percent whole wheat inclusion, until they reached 28 days of age. Weekly live weights, feed intake, average daily gain and the average daily feed intake were recorded and calculated. At the end of the grower (day 21) and finisher phase (day 28), one broiler bird was selected per cage to have eight (8) birds per treatment and 16 birds per phase that were slaughtered and breast meat samples were analysed in duplicate for the presence of soy and gluten allergens using ELISA kits. The dressing percentage of hot carcasses was also determined at the end of the finisher phase on eight birds per treatment. For LW hens, live weight (LW) at 39 weeks of age, the average daily feed intake (ADFI) and weekly feed intakes (FI) were significantly different (P < 0.05) between treatments with birds on T2 recording higher gains. As birds age in weeks increased, significant differences (P < 0.05) in live weight values were recorded. Egg quality traits measured (shell weight, yolk weight, albumen weight, albumen height and Haugh units) were significantly different (P < 0.05) between treatments, with eggs from hens receiving T1 recording higher mean values. As hens got older, the colour of egg yolk improved, producing eggs with higher b* (yellowness) values and lower L* (lightness) and a* (redness) mean values. The Haugh unit, significantly improved (P < 0.05) as the hens got older, signifying better quality of eggs. For the broiler birds, growth traits measured indicated that there were no significant differences (P > 0.05) in live weight (LW), average daily feed intake (ADFI), weekly feed intake (FI), feed conversion ratio (FCR), cumulative feed intake (CFI) and cumulative gain (CG) between treatments. No significant differences (P > 0.05) between dressing percentage of broilers from the two treatments were observed. As birds grew, significant differences (P < 0.05) in LW, FI, AFI, FCR, and CFI, over a four-week period were recorded. Results of the allergen analyses indicated that soy and gluten allergens were not carried over from feed into eggs and meat of chickens fed a maize/soya bean-based diet and a maize/soya bean-based with a 15 percent whole wheat inclusion, respectively. In conclusion, a maize/soya bean-based diet and maize/soya bean-based diet with a 15 percent whole wheat inclusion that contained soy and gluten allergens, are feed sources that promote and stimulate 36-week-old LW hen and Ross 308 chicken growth.
- Full Text:
- Authors: Dokora, Adia-En-Michelle
- Date: 2015
- Subjects: Chickens -- Nutrition Chickens --Feeding and feeds Meat -- Quality
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: http://hdl.handle.net/10353/2946 , vital:28192
- Description: This study determined the effect of maize-, whole wheat-, soya bean-based-diets on the growth performance, egg quality and dressing percentage of chickens, as well as the potential for soy and gluten allergen carryover to eggs and meat from chickens. Twenty 36-week-old Lorham White (LW) hens were divided into two groups and kept in individual cages until they reached 39-weeks of age, with water and feed supplied ad libitum. Ten LW hens were fed a maize/soya bean-based diet (T1) and the other ten birds were fed a maize/soya bean-based diet with a 15 percent whole wheat inclusion (T2) for a period of four weeks, with weekly individual hen weights and group feed consumption figures being recorded. After a two-week diet adaptation period, six eggs per treatment group were collected every second day from the LW hens’ to measure egg quality traits. Every third day, over a 29-day period, six eggs per treatment were collected and analysed for the presence of soy, gluten and gluten-derived peptides using allergen specific enzyme linked immunosorbent assays (ELISA) kits. For the broiler trial, a total of 160 Ross 308 mixed sex day old chicks were used in a completely randomized design. Two dietary treatments were assigned to eight cages (replicate) per treatment, with ten birds per cage. The Ross 308 broiler feeding programme consisted of three phases, starter (day 1 to day 10), grower (day 11 to day 20) and finisher (day 21 to day 28). At the beginning of the trial all chicks were fed T1 which contained a maize/soya bean-based diet for a period of 10 days and then eight cages with 10 birds per cage were randomly selected and fed the T2 diet, which contained a maize/soya bean-based diet with a 15 percent whole wheat inclusion, until they reached 28 days of age. Weekly live weights, feed intake, average daily gain and the average daily feed intake were recorded and calculated. At the end of the grower (day 21) and finisher phase (day 28), one broiler bird was selected per cage to have eight (8) birds per treatment and 16 birds per phase that were slaughtered and breast meat samples were analysed in duplicate for the presence of soy and gluten allergens using ELISA kits. The dressing percentage of hot carcasses was also determined at the end of the finisher phase on eight birds per treatment. For LW hens, live weight (LW) at 39 weeks of age, the average daily feed intake (ADFI) and weekly feed intakes (FI) were significantly different (P < 0.05) between treatments with birds on T2 recording higher gains. As birds age in weeks increased, significant differences (P < 0.05) in live weight values were recorded. Egg quality traits measured (shell weight, yolk weight, albumen weight, albumen height and Haugh units) were significantly different (P < 0.05) between treatments, with eggs from hens receiving T1 recording higher mean values. As hens got older, the colour of egg yolk improved, producing eggs with higher b* (yellowness) values and lower L* (lightness) and a* (redness) mean values. The Haugh unit, significantly improved (P < 0.05) as the hens got older, signifying better quality of eggs. For the broiler birds, growth traits measured indicated that there were no significant differences (P > 0.05) in live weight (LW), average daily feed intake (ADFI), weekly feed intake (FI), feed conversion ratio (FCR), cumulative feed intake (CFI) and cumulative gain (CG) between treatments. No significant differences (P > 0.05) between dressing percentage of broilers from the two treatments were observed. As birds grew, significant differences (P < 0.05) in LW, FI, AFI, FCR, and CFI, over a four-week period were recorded. Results of the allergen analyses indicated that soy and gluten allergens were not carried over from feed into eggs and meat of chickens fed a maize/soya bean-based diet and a maize/soya bean-based with a 15 percent whole wheat inclusion, respectively. In conclusion, a maize/soya bean-based diet and maize/soya bean-based diet with a 15 percent whole wheat inclusion that contained soy and gluten allergens, are feed sources that promote and stimulate 36-week-old LW hen and Ross 308 chicken growth.
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Medicinal properties of Moringa (Moringa Oleifera Lam) leaves and the effect of its use as a supplement on goat growth performance and meat characteristics
- Moyo, Busani https://orcid.org/0000-0001-7002-7266
- Authors: Moyo, Busani https://orcid.org/0000-0001-7002-7266
- Date: 2011-09
- Subjects: Moringa , Medicinal plants
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/24376 , vital:62662
- Description: The main objective of the study was to determine if feeding goats with Moringa oleifera leaves would lead to an increase in productivity and in value of the meat. The proximate, van Soet, atomic absorption spectrophotometric and soxhlet extraction methods were used to determine the nutritional value M. oleifera leaves of the South African. The in-vitro antimicrobial screening methods were used to determine antimicrobial activities M. oleifera extracts while in vitro and invivo models were used to determine the antioxidant activities of M. oleifera leaves. An evaluation of the potential of M. oleifera leaf meal as a feed supplement in terms of its effect on helminth load, goat growth performance, carcass characteristics, meat quality attributes, nutritional and consumer sensory characteristics of goat meat was done. A total of 24, eight month old goats were randomly allocated to dietary treatments of M. oleifera leaf meal (MOL), sunflower seed cake (SC) and GH (grass hay) which was the control. All the groups were fed on basal diet of grass hay ad libitum and 200g wheat bran per head per day. The MOL group was given an additional 200 g of dried M. oleifera leaves while the SC group was offered 170 g sunflower seed cake per head/day. The study showed that the dried leaves had crude protein levels of 30.3 percent, polyunsaturated fatty acids (52.21 percent), Saturated fatty acids (43.31), n-3 (44.57 percent), n-6 (7.64 percent), 19 amino acids, vitamin E (77 mg/100 g) and Beta-carotene (18.5 mg/100 g). The M. oleifera leaf extracts showed antibacterial activities against Escherichia coli, Enterobacter cloace, Proteus vulgaris, Staphylococcus aureus and Micrococcus kristinae. The supplementation of goats with MOL and SC resulted in decreased feacal larval count and lower Haemonchus contortus, Trichostrongylus colubriforms and Oesophagastum columbianum worm burdens than those in the non-supplemented goats. Goats supplemented with SC and MOL had higher average daily weight gain and heavier carcasses than those in the GH group. Higher pH1 scores were observed in chevon from GH diet than the supplemented ones. The MOL and SC supplemented goats had chevon with higher values for lightness (L*) 24 hr post-mortem than the one from the GH group. The redness (a*) values of chevon 24 hr post mortem was highest in MOL supplemented goats. Warner Bratzler shear force (WBSF) values of SC (30.1 N) and MOL (29.8 N) supplemented goats were lower than those from GH diet (32.6 N). Chevon from goats fed GH diet had significantly higher cooking losses (29.5 percent) than that from MOL (25.4 percent) and SC (25.6 percent) fed groups. It was observed that chevon from MOL and SC supplemented groups had higher crude protein (23.57 and 22.95 percent, respectively) than the one from the GH group (21.20 percent). Cholesterol levels were higher in chevon from SC (42.84) supplemented goats than those from MOL (38.76) and GH (35.63 mg). Chevon from GH and MOL group had higher (P < 0.05) proportions of PUFA, n-3, PUFA/SFA ratio and lower n-6/n-3 ratio. Mean consumer scores for first bite, aroma, flavour and juiceness were higher in the MOL group than in the GH group (P < 0.05). The acetone extract exhibited higher concentrations of total flavonoids, flavonols, phenolics. The acetone extracts depicted higher percentage inhibition against DPPH, ABTS and nitric oxide radicals which were comparable with reference antioxidant (vitamin C and BHT). The M. oleifera leaf meal increased the antioxidant activity of GSH, SOD and catalase. Moringa oleifera leaves also exhibited medicinal properties by having anthelmintic, antibacterial activities and showed antioxidant properties. It was also observed that protein supplementation improved the animal growth performance, the physico-chemical characteristics, nutritional and fatty acids composition of meat hence meeting the consumer needs. , Thesis (PhD) -- Faculty of Science and Agriculture, 2011
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- Authors: Moyo, Busani https://orcid.org/0000-0001-7002-7266
- Date: 2011-09
- Subjects: Moringa , Medicinal plants
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/24376 , vital:62662
- Description: The main objective of the study was to determine if feeding goats with Moringa oleifera leaves would lead to an increase in productivity and in value of the meat. The proximate, van Soet, atomic absorption spectrophotometric and soxhlet extraction methods were used to determine the nutritional value M. oleifera leaves of the South African. The in-vitro antimicrobial screening methods were used to determine antimicrobial activities M. oleifera extracts while in vitro and invivo models were used to determine the antioxidant activities of M. oleifera leaves. An evaluation of the potential of M. oleifera leaf meal as a feed supplement in terms of its effect on helminth load, goat growth performance, carcass characteristics, meat quality attributes, nutritional and consumer sensory characteristics of goat meat was done. A total of 24, eight month old goats were randomly allocated to dietary treatments of M. oleifera leaf meal (MOL), sunflower seed cake (SC) and GH (grass hay) which was the control. All the groups were fed on basal diet of grass hay ad libitum and 200g wheat bran per head per day. The MOL group was given an additional 200 g of dried M. oleifera leaves while the SC group was offered 170 g sunflower seed cake per head/day. The study showed that the dried leaves had crude protein levels of 30.3 percent, polyunsaturated fatty acids (52.21 percent), Saturated fatty acids (43.31), n-3 (44.57 percent), n-6 (7.64 percent), 19 amino acids, vitamin E (77 mg/100 g) and Beta-carotene (18.5 mg/100 g). The M. oleifera leaf extracts showed antibacterial activities against Escherichia coli, Enterobacter cloace, Proteus vulgaris, Staphylococcus aureus and Micrococcus kristinae. The supplementation of goats with MOL and SC resulted in decreased feacal larval count and lower Haemonchus contortus, Trichostrongylus colubriforms and Oesophagastum columbianum worm burdens than those in the non-supplemented goats. Goats supplemented with SC and MOL had higher average daily weight gain and heavier carcasses than those in the GH group. Higher pH1 scores were observed in chevon from GH diet than the supplemented ones. The MOL and SC supplemented goats had chevon with higher values for lightness (L*) 24 hr post-mortem than the one from the GH group. The redness (a*) values of chevon 24 hr post mortem was highest in MOL supplemented goats. Warner Bratzler shear force (WBSF) values of SC (30.1 N) and MOL (29.8 N) supplemented goats were lower than those from GH diet (32.6 N). Chevon from goats fed GH diet had significantly higher cooking losses (29.5 percent) than that from MOL (25.4 percent) and SC (25.6 percent) fed groups. It was observed that chevon from MOL and SC supplemented groups had higher crude protein (23.57 and 22.95 percent, respectively) than the one from the GH group (21.20 percent). Cholesterol levels were higher in chevon from SC (42.84) supplemented goats than those from MOL (38.76) and GH (35.63 mg). Chevon from GH and MOL group had higher (P < 0.05) proportions of PUFA, n-3, PUFA/SFA ratio and lower n-6/n-3 ratio. Mean consumer scores for first bite, aroma, flavour and juiceness were higher in the MOL group than in the GH group (P < 0.05). The acetone extract exhibited higher concentrations of total flavonoids, flavonols, phenolics. The acetone extracts depicted higher percentage inhibition against DPPH, ABTS and nitric oxide radicals which were comparable with reference antioxidant (vitamin C and BHT). The M. oleifera leaf meal increased the antioxidant activity of GSH, SOD and catalase. Moringa oleifera leaves also exhibited medicinal properties by having anthelmintic, antibacterial activities and showed antioxidant properties. It was also observed that protein supplementation improved the animal growth performance, the physico-chemical characteristics, nutritional and fatty acids composition of meat hence meeting the consumer needs. , Thesis (PhD) -- Faculty of Science and Agriculture, 2011
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