Avoidance-related behaviour, bleeding times and the quality of meat from sheep slaughtered at a commercial and a municipal abattoir
- Authors: Njisane, Yonela Zifikile
- Date: 2012
- Subjects: Mutton -- Quality , Sheep -- Quality , Slaughtering and slaughter-houses -- South Africa , Animal behavior , Dorper sheep , Meat -- Quality , Sheep -- Carcasses -- Handling
- Language: English
- Type: Thesis , Masters , MSc Agric (Animal Science)
- Identifier: vital:11818 , http://hdl.handle.net/10353/d1004195 , Mutton -- Quality , Sheep -- Quality , Slaughtering and slaughter-houses -- South Africa , Animal behavior , Dorper sheep , Meat -- Quality , Sheep -- Carcasses -- Handling
- Description: The objective of the study was to determine the avoidance-related behaviour, bleeding times and the quality of meat from sheep of different gender, breed (Dorper, Merino, and their crosses) and age groups, slaughtered at a commercial and municipal abattoir. Castrates and ewes of different age groups (1= <10months, 2= 11-12months, and 3= >12months) and breeds were used. From the commercial abattoir, 90 castrates and 110 ewes were used, while 66 castrates and 19 ewes were obtained from the municipal abattoir. Meat samples were obtained to determine meat colour, ultimate pH, temperature, cooking loss and tenderness. Correlations between bleeding times and meat quality variables were also determined. The two abattoirs differed in terms of technology and the procedures used, and this brought about different response behaviours in sheep at slaughter, bleeding times at exsanguination and the quality of meat produced. Animal-related factors (breed, gender and age classes) had no effect on the avoidance-related behaviour of sheep slaughtered at the commercial abattoir, while these factors affected those sheep slaughtered at the municipal abattoir. These factors also had an effect on the quality of meat produced at both abattoirs. Gender and weight of the animals had effects on the bleeding times at exsanguination at both abattoirs. Bleeding times did no correlate with any of the meat quality variables, but correlations among meat quality variables were observed. Avoidance-related behaviour, bleeding times, and the quality of mutton from sheep slaughtered at a commercial and a municipal abattoir was affected by breed, age, and gender.
- Full Text:
- Authors: Njisane, Yonela Zifikile
- Date: 2012
- Subjects: Mutton -- Quality , Sheep -- Quality , Slaughtering and slaughter-houses -- South Africa , Animal behavior , Dorper sheep , Meat -- Quality , Sheep -- Carcasses -- Handling
- Language: English
- Type: Thesis , Masters , MSc Agric (Animal Science)
- Identifier: vital:11818 , http://hdl.handle.net/10353/d1004195 , Mutton -- Quality , Sheep -- Quality , Slaughtering and slaughter-houses -- South Africa , Animal behavior , Dorper sheep , Meat -- Quality , Sheep -- Carcasses -- Handling
- Description: The objective of the study was to determine the avoidance-related behaviour, bleeding times and the quality of meat from sheep of different gender, breed (Dorper, Merino, and their crosses) and age groups, slaughtered at a commercial and municipal abattoir. Castrates and ewes of different age groups (1= <10months, 2= 11-12months, and 3= >12months) and breeds were used. From the commercial abattoir, 90 castrates and 110 ewes were used, while 66 castrates and 19 ewes were obtained from the municipal abattoir. Meat samples were obtained to determine meat colour, ultimate pH, temperature, cooking loss and tenderness. Correlations between bleeding times and meat quality variables were also determined. The two abattoirs differed in terms of technology and the procedures used, and this brought about different response behaviours in sheep at slaughter, bleeding times at exsanguination and the quality of meat produced. Animal-related factors (breed, gender and age classes) had no effect on the avoidance-related behaviour of sheep slaughtered at the commercial abattoir, while these factors affected those sheep slaughtered at the municipal abattoir. These factors also had an effect on the quality of meat produced at both abattoirs. Gender and weight of the animals had effects on the bleeding times at exsanguination at both abattoirs. Bleeding times did no correlate with any of the meat quality variables, but correlations among meat quality variables were observed. Avoidance-related behaviour, bleeding times, and the quality of mutton from sheep slaughtered at a commercial and a municipal abattoir was affected by breed, age, and gender.
- Full Text:
Bruising in slaughter cattle: its relationship with creatine kinase (CK) levels and meat quality
- Authors: Mpakama, Thandiswa
- Date: 2012
- Subjects: Beef quality , Creatine kinase , Cattle -- Transportation
- Language: English
- Type: Thesis , Masters , MSc Agric (Animal Science)
- Identifier: vital:11821 , http://hdl.handle.net/10353/d1006850 , Beef quality , Creatine kinase , Cattle -- Transportation
- Description: The objective of the study was to determine the effects of pre-slaughter conditions and anima-l related factors on bruising, creatine kinase (CK) and beef quality. Three hundred and twenty one cattle from three breeds (108 Bonsmara, 130 Beefmaster and 83 Brahman) were used in this study. The animals were grouped according to age categories as follows; Group 1(16months), Group 2 (18months) and Group 3 (24 months). Blood samples for CK determination were collected at exsanguisation using disposable vacutainer tubes. The Muscularis longisimus thoracis et lumborum (LTL) muscle was used to determine beef colour (L,* a* and b*) and ultimate pH. Significant P (<0.05) breed effects were observed on bruising score and CK levels with Bonsmara breed having the highest percentage (80 percent) of bruising score and higher CK (705.3±80.57) values. The higher CK levels were also in winter season. The effect of breed, sex and age at slaughter on meat quality (pHu, L*, a*, b*) was also observed. There were positive correlations between distance travelled and meat quality, while there was no relationship observed between CK and distance travelled. Therefore, it was concluded that animal related factors had an effect on meat quality and CK levels.
- Full Text:
- Authors: Mpakama, Thandiswa
- Date: 2012
- Subjects: Beef quality , Creatine kinase , Cattle -- Transportation
- Language: English
- Type: Thesis , Masters , MSc Agric (Animal Science)
- Identifier: vital:11821 , http://hdl.handle.net/10353/d1006850 , Beef quality , Creatine kinase , Cattle -- Transportation
- Description: The objective of the study was to determine the effects of pre-slaughter conditions and anima-l related factors on bruising, creatine kinase (CK) and beef quality. Three hundred and twenty one cattle from three breeds (108 Bonsmara, 130 Beefmaster and 83 Brahman) were used in this study. The animals were grouped according to age categories as follows; Group 1(16months), Group 2 (18months) and Group 3 (24 months). Blood samples for CK determination were collected at exsanguisation using disposable vacutainer tubes. The Muscularis longisimus thoracis et lumborum (LTL) muscle was used to determine beef colour (L,* a* and b*) and ultimate pH. Significant P (<0.05) breed effects were observed on bruising score and CK levels with Bonsmara breed having the highest percentage (80 percent) of bruising score and higher CK (705.3±80.57) values. The higher CK levels were also in winter season. The effect of breed, sex and age at slaughter on meat quality (pHu, L*, a*, b*) was also observed. There were positive correlations between distance travelled and meat quality, while there was no relationship observed between CK and distance travelled. Therefore, it was concluded that animal related factors had an effect on meat quality and CK levels.
- Full Text:
Effect of full and semi-scavenging rearing systems on crop contents and the quality of meat from village chickens during spring season of Eastern Cape, South Africa
- Authors: Hanyani, Charles Tawanda
- Date: 2012
- Subjects: Chickens -- Feeding and feeds -- South Africa -- Eastern Cape , Chicken breeds -- South Africa -- Eastern Cape , Meat -- Quality -- South Africa -- Eastern Cape , Forage plants -- South Africa -- Eastern Cape , Crops -- Nutrition -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc Agric (Animal Science)
- Identifier: vital:11807 , http://hdl.handle.net/10353/440 , Chickens -- Feeding and feeds -- South Africa -- Eastern Cape , Chicken breeds -- South Africa -- Eastern Cape , Meat -- Quality -- South Africa -- Eastern Cape , Forage plants -- South Africa -- Eastern Cape , Crops -- Nutrition -- South Africa -- Eastern Cape
- Description: The objective of this study was to compare the nutrient status of full scavenging and semi-scavenging village chicken production systems. The semi-scavenging chickens were given broiler finisher mash between 14-24 weeks of age, whilst the full scavenging relied on natural foraging. The study also sought to compare the quality of meat from chickens from the two systems. After slaughtering the chickens, the crop contents were physically separated and analysed for chemical composition. Meat pH and colour were measured on the breast muscle of individual carcasses and a consumer sensory evaluation was also done on the breast muscle. The mean crop content weights per day were significantly higher in full scavenging chickens (±16.7g/day biomass) than in semi-scavenging chickens (±9.14g/day). Dry matter, calcium, and phosphorus levels were higher in the crop contents of the full than in the semi-scavenging chickens but crude protein, crude fibre and metabolisable energy were higher in the latter system. Semi-scavenging (1.3 ± 0.05kg) carcasses were heavier (P<0.05) than full scavenging ones (1.0 ± 0.06kg). The ultimate pH (24h) (pHu) of meat from full scavenging chickens (6.0 ± 0.03) was higher (P<0.05) than that of meat from the semi-scavenging chickens (5.7 ± 0.04). Meat from the full scavenging chickens had higher L* values (60 ± 1.2) than meat from the semi-scavenging chickens (47 ± 0.8). The a* value of meat of full scavenging chickens was significantly (P<0.05) less (4 ± 0.4) than that of meat from semi-scavenging chickens (15 ± 1.3). There was a significant positive (0.60) correlation between pHu and L* of meat from village chickens across rearing systems. The semi-scavenging system meat had better sensory attributes than the meat from the full scavenging system. Female consumers scored the typical flavour of village chicken meat across rearing systems higher (P< 0.05) than male consumers. The Shona consumers scored the meat higher (P< 0.05) than the Xhosa, Zulu, Ndebele and other tribes for initial juiciness, first bite impression and muscle fibre and tenderness of the chicken across rearing systems. Consumers scored of the meat from the semi-scavenging system higher (P<0.05) on initial juiciness (4.3 ± 0.20), first bite impression (4.2 ± 0.197), muscle fibre tenderness (4.5 ± 0.217) than meat from the full scavenging chickens. There were positive correlations (0.46) between aroma intensity and overall flavour intensity across both rearing systems. The semi-scavenging system produced better carcass characteristics, lighter (L*) meat and more consumer acceptable meat than full scavenging chickens. Therefore the full scavenging rearing system had better nutrient composition in its scavenging feed resource base, although the semi-scavenging systems produced chickens with better carcass, meat pH, colour and sensory characteristics than the full scavenging chickens.
- Full Text:
- Authors: Hanyani, Charles Tawanda
- Date: 2012
- Subjects: Chickens -- Feeding and feeds -- South Africa -- Eastern Cape , Chicken breeds -- South Africa -- Eastern Cape , Meat -- Quality -- South Africa -- Eastern Cape , Forage plants -- South Africa -- Eastern Cape , Crops -- Nutrition -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc Agric (Animal Science)
- Identifier: vital:11807 , http://hdl.handle.net/10353/440 , Chickens -- Feeding and feeds -- South Africa -- Eastern Cape , Chicken breeds -- South Africa -- Eastern Cape , Meat -- Quality -- South Africa -- Eastern Cape , Forage plants -- South Africa -- Eastern Cape , Crops -- Nutrition -- South Africa -- Eastern Cape
- Description: The objective of this study was to compare the nutrient status of full scavenging and semi-scavenging village chicken production systems. The semi-scavenging chickens were given broiler finisher mash between 14-24 weeks of age, whilst the full scavenging relied on natural foraging. The study also sought to compare the quality of meat from chickens from the two systems. After slaughtering the chickens, the crop contents were physically separated and analysed for chemical composition. Meat pH and colour were measured on the breast muscle of individual carcasses and a consumer sensory evaluation was also done on the breast muscle. The mean crop content weights per day were significantly higher in full scavenging chickens (±16.7g/day biomass) than in semi-scavenging chickens (±9.14g/day). Dry matter, calcium, and phosphorus levels were higher in the crop contents of the full than in the semi-scavenging chickens but crude protein, crude fibre and metabolisable energy were higher in the latter system. Semi-scavenging (1.3 ± 0.05kg) carcasses were heavier (P<0.05) than full scavenging ones (1.0 ± 0.06kg). The ultimate pH (24h) (pHu) of meat from full scavenging chickens (6.0 ± 0.03) was higher (P<0.05) than that of meat from the semi-scavenging chickens (5.7 ± 0.04). Meat from the full scavenging chickens had higher L* values (60 ± 1.2) than meat from the semi-scavenging chickens (47 ± 0.8). The a* value of meat of full scavenging chickens was significantly (P<0.05) less (4 ± 0.4) than that of meat from semi-scavenging chickens (15 ± 1.3). There was a significant positive (0.60) correlation between pHu and L* of meat from village chickens across rearing systems. The semi-scavenging system meat had better sensory attributes than the meat from the full scavenging system. Female consumers scored the typical flavour of village chicken meat across rearing systems higher (P< 0.05) than male consumers. The Shona consumers scored the meat higher (P< 0.05) than the Xhosa, Zulu, Ndebele and other tribes for initial juiciness, first bite impression and muscle fibre and tenderness of the chicken across rearing systems. Consumers scored of the meat from the semi-scavenging system higher (P<0.05) on initial juiciness (4.3 ± 0.20), first bite impression (4.2 ± 0.197), muscle fibre tenderness (4.5 ± 0.217) than meat from the full scavenging chickens. There were positive correlations (0.46) between aroma intensity and overall flavour intensity across both rearing systems. The semi-scavenging system produced better carcass characteristics, lighter (L*) meat and more consumer acceptable meat than full scavenging chickens. Therefore the full scavenging rearing system had better nutrient composition in its scavenging feed resource base, although the semi-scavenging systems produced chickens with better carcass, meat pH, colour and sensory characteristics than the full scavenging chickens.
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Effect of stage of lactation on milk yield, somatic cell counts, mineral and fatty acid profiles in pasture-based Friesian, Jersey and Friesian × Jersey cows
- Nantapo, Carlos Wyson Tawanda
- Authors: Nantapo, Carlos Wyson Tawanda
- Date: 2012
- Subjects: Trace elements in animal nutrition , Genotype-environment interaction , Milk yield -- Testing , Lactation , Holstein-Friesian cattle , Jersey cattle
- Language: English
- Type: Thesis , Masters , MSc Agric (Animal Science)
- Identifier: vital:11819 , http://hdl.handle.net/10353/d1006810 , Trace elements in animal nutrition , Genotype-environment interaction , Milk yield -- Testing , Lactation , Holstein-Friesian cattle , Jersey cattle
- Description: The effect of stage of lactation on milk yield, somatic cell counts, mineral and fatty acid profiles in pasture-based Friesian, Jersey and Friesian × Jersey cows was investigated. Twenty Friesian, twenty Jersey and twenty Friesian × Jersey cows were randomly selected from a dairy herd. A total of 202 milk samples were collected and analysed in three stages of lactation. Genotypic differences were observed in milk yield and fat content. Friesian cows produced the highest yield and lowest fat content whereas the opposite was true for Jersey cows (P<0.01). No significant differences were observed in SCC in the different genotypes, but SCC levels were higher in mid and late lactation (P<0.001). There was no effect (P<0.005) of genotype and stage of lactation interaction on Ca, P, Mg, Na, Mn and Bo concentration. Jersey cows had the least concentration of Fe and Cu in all stages of lactation. Strong positive correlations were observed among Ca and P, Mg and Zn. Aluminium had a strong positive relationship with Bo, Fe, Mn and Zn (P<0.001). Generally, SCC had a weak positive relationship with macro elements but a significant negative relationship with microelements. Yield levels were negatively correlated with Mg, Na, Al, Mn and SCC. Pasture ALA, SFA, n-3, n-6/n-3 and PUFA/MUFA concentration did not differ across the study period. Linoleic acid was highest in the second phase which coincides with mid lactation in cows (P<0.001). Highest moisture content coincided with the least fat free dry matter content in early lactation (P<0.001). Significantly high fat content was observed in late lactation than in early lactation. Highest butyric, caproic, linoleic, n-6 and PUFA were observed for Friesian cows. All other fatty acids ratios were not significantly different among different genotypes. Highest CLA, ALA, LA, SFA, PUFA, n-6, and n-3 and atherogenicity index were observed in early lactation whereas desaturase activity indices were highest in late lactation. Strong positive correlations were observed among milk vaccenic, ALA, LA and CLA concentrations. Inverse relationships were observed between SFA and long chain fatty acids. It can be concluded, it may be of advantage to consume milk from early stage of lactation poses a lower risk to coronary diseases and are much safer to consume.
- Full Text:
- Authors: Nantapo, Carlos Wyson Tawanda
- Date: 2012
- Subjects: Trace elements in animal nutrition , Genotype-environment interaction , Milk yield -- Testing , Lactation , Holstein-Friesian cattle , Jersey cattle
- Language: English
- Type: Thesis , Masters , MSc Agric (Animal Science)
- Identifier: vital:11819 , http://hdl.handle.net/10353/d1006810 , Trace elements in animal nutrition , Genotype-environment interaction , Milk yield -- Testing , Lactation , Holstein-Friesian cattle , Jersey cattle
- Description: The effect of stage of lactation on milk yield, somatic cell counts, mineral and fatty acid profiles in pasture-based Friesian, Jersey and Friesian × Jersey cows was investigated. Twenty Friesian, twenty Jersey and twenty Friesian × Jersey cows were randomly selected from a dairy herd. A total of 202 milk samples were collected and analysed in three stages of lactation. Genotypic differences were observed in milk yield and fat content. Friesian cows produced the highest yield and lowest fat content whereas the opposite was true for Jersey cows (P<0.01). No significant differences were observed in SCC in the different genotypes, but SCC levels were higher in mid and late lactation (P<0.001). There was no effect (P<0.005) of genotype and stage of lactation interaction on Ca, P, Mg, Na, Mn and Bo concentration. Jersey cows had the least concentration of Fe and Cu in all stages of lactation. Strong positive correlations were observed among Ca and P, Mg and Zn. Aluminium had a strong positive relationship with Bo, Fe, Mn and Zn (P<0.001). Generally, SCC had a weak positive relationship with macro elements but a significant negative relationship with microelements. Yield levels were negatively correlated with Mg, Na, Al, Mn and SCC. Pasture ALA, SFA, n-3, n-6/n-3 and PUFA/MUFA concentration did not differ across the study period. Linoleic acid was highest in the second phase which coincides with mid lactation in cows (P<0.001). Highest moisture content coincided with the least fat free dry matter content in early lactation (P<0.001). Significantly high fat content was observed in late lactation than in early lactation. Highest butyric, caproic, linoleic, n-6 and PUFA were observed for Friesian cows. All other fatty acids ratios were not significantly different among different genotypes. Highest CLA, ALA, LA, SFA, PUFA, n-6, and n-3 and atherogenicity index were observed in early lactation whereas desaturase activity indices were highest in late lactation. Strong positive correlations were observed among milk vaccenic, ALA, LA and CLA concentrations. Inverse relationships were observed between SFA and long chain fatty acids. It can be concluded, it may be of advantage to consume milk from early stage of lactation poses a lower risk to coronary diseases and are much safer to consume.
- Full Text:
Effects of feeding Moringa Oleifera leaf meal as an additive on growth performance of chicken, physico-chemical shelf-life indicators, fatty acid profiles and lipid oxidation of broiler meat
- Authors: Wapi, Cwayita
- Date: 2012
- Subjects: Moringa , Broilers (Chickens) , Meat -- Quality
- Language: English
- Type: Thesis , Masters , MSc Agric (Animal Science)
- Identifier: vital:11822 , http://hdl.handle.net/10353/d1007546 , Moringa , Broilers (Chickens) , Meat -- Quality
- Description: Effects of feeding Moringa oleifera leaf meal as an additive on growth performance of chicken, physico- chemical shelf-life indicators, fatty acids profiles and lipid oxidation of broiler meat The main objective of the study was to determine the effect of M.oleifera leaf meal (MOLM) as an additive on growth performance, carcass characteristics, physico-chemical shelf-life indicators (colour, ultimate pH, driploss), fatty acids profiles and lipid oxidation of meat from broilers. A total of 432 1day old unsexed broiler chicks (Aviane 48) were randomly allocated to four dietary treatments (TRTS) in 72 cages. There were 18 cages per treatment and each cage allocated 6 chicks. Water and feed was provided at ad libitum. The feeding phases were, prestarter (0-7 Days), starter (8-18 Days), grower (19-28 Days), finisher (29-35 Days). The four TRTS contained graded levels of MOLM at 1000g/ton, 750g/ton, 500g/ton, and 0g/ton (control), respectively. The birds were slaughtered at 35 days of age. Breast muscles were sampled for meat, ultimate pH (pHu ), colour, drip loss over a 7 days shelf-life test. After each day’s test sub-samples were dipped in liquid nitrogen and kept at -180 C for thiobarbituric acid reactive substances determination. On Day1 and Day 7 extra sub-samples were also kept at -180 C for fatty acids analysis.The TRTS had no effect on average feed intake (AFI), feed conversion efficiency (FCE), and on average daily gain (ADG). Slaughter weight (SW), carcass weight (CW), dressing percentage and gizzard weight (GW) values were similar in all TRTS. Liver weight (LW), heart weight (HW), and gastro-intestinal fat (GIF) differed in all the TRTS, with treatment 2 having the highest value of HW (28.3±2.55), and LW (44.2±1.60) was the highest on treatment 4 . The pH values in all TRTS were constant from Day1 to Day5, reached peak on Day6, and then declined on Day7. Meat from broilers given treatment 1 with MOLM (1000g/ton) had the highest lightness (L*) values. The redness (a*) values were the highest in meat from treatment 2 (750g/ton MOLM). Treatments had no effect on yellowness (b*) values and on drip loss of the breasts. During storage L* values were high from Day1 to Day5 and decreased from Day6 to Day7. Drip loss increased with storage time as expected. Treatment 4 (control) had the highest proportions of poly-unsaturated fatty acids (PUFA) (30.3±1.87). Treatment 1 (1000g/ton) had the highest proportion of saturated fatty acids (SFA) (60.9±1.87). Treatment 1 (1000g/ton) had the highest proportion of SFA (60.9±4.30). Treatment 2 (750g/ton) had the highest n-6/n-3 ratio than other TRTS. Days had no effect (P>0.05) on PUFA, SFA, and n-6/n-3 ratio. Treatment 1 had a highest amount of malondialdehyde (MDA), treatment 4 had no effect (P>0.05) on MDA . Storage time had an effect (P<0.05) on MDA levels, except for on Day1 and Day7. Day2 had the highest amount of MDA (0.7±0.08). The use of MOLM as an additive in broiler diets reduced lipid oxidation in meat, and maintained the quality of the broiler meat during storage. It also did not have any adverse effects on the growth performance of broilers. Therefore, it has the potential to be used as an additive in broiler diets.
- Full Text:
- Authors: Wapi, Cwayita
- Date: 2012
- Subjects: Moringa , Broilers (Chickens) , Meat -- Quality
- Language: English
- Type: Thesis , Masters , MSc Agric (Animal Science)
- Identifier: vital:11822 , http://hdl.handle.net/10353/d1007546 , Moringa , Broilers (Chickens) , Meat -- Quality
- Description: Effects of feeding Moringa oleifera leaf meal as an additive on growth performance of chicken, physico- chemical shelf-life indicators, fatty acids profiles and lipid oxidation of broiler meat The main objective of the study was to determine the effect of M.oleifera leaf meal (MOLM) as an additive on growth performance, carcass characteristics, physico-chemical shelf-life indicators (colour, ultimate pH, driploss), fatty acids profiles and lipid oxidation of meat from broilers. A total of 432 1day old unsexed broiler chicks (Aviane 48) were randomly allocated to four dietary treatments (TRTS) in 72 cages. There were 18 cages per treatment and each cage allocated 6 chicks. Water and feed was provided at ad libitum. The feeding phases were, prestarter (0-7 Days), starter (8-18 Days), grower (19-28 Days), finisher (29-35 Days). The four TRTS contained graded levels of MOLM at 1000g/ton, 750g/ton, 500g/ton, and 0g/ton (control), respectively. The birds were slaughtered at 35 days of age. Breast muscles were sampled for meat, ultimate pH (pHu ), colour, drip loss over a 7 days shelf-life test. After each day’s test sub-samples were dipped in liquid nitrogen and kept at -180 C for thiobarbituric acid reactive substances determination. On Day1 and Day 7 extra sub-samples were also kept at -180 C for fatty acids analysis.The TRTS had no effect on average feed intake (AFI), feed conversion efficiency (FCE), and on average daily gain (ADG). Slaughter weight (SW), carcass weight (CW), dressing percentage and gizzard weight (GW) values were similar in all TRTS. Liver weight (LW), heart weight (HW), and gastro-intestinal fat (GIF) differed in all the TRTS, with treatment 2 having the highest value of HW (28.3±2.55), and LW (44.2±1.60) was the highest on treatment 4 . The pH values in all TRTS were constant from Day1 to Day5, reached peak on Day6, and then declined on Day7. Meat from broilers given treatment 1 with MOLM (1000g/ton) had the highest lightness (L*) values. The redness (a*) values were the highest in meat from treatment 2 (750g/ton MOLM). Treatments had no effect on yellowness (b*) values and on drip loss of the breasts. During storage L* values were high from Day1 to Day5 and decreased from Day6 to Day7. Drip loss increased with storage time as expected. Treatment 4 (control) had the highest proportions of poly-unsaturated fatty acids (PUFA) (30.3±1.87). Treatment 1 (1000g/ton) had the highest proportion of saturated fatty acids (SFA) (60.9±1.87). Treatment 1 (1000g/ton) had the highest proportion of SFA (60.9±4.30). Treatment 2 (750g/ton) had the highest n-6/n-3 ratio than other TRTS. Days had no effect (P>0.05) on PUFA, SFA, and n-6/n-3 ratio. Treatment 1 had a highest amount of malondialdehyde (MDA), treatment 4 had no effect (P>0.05) on MDA . Storage time had an effect (P<0.05) on MDA levels, except for on Day1 and Day7. Day2 had the highest amount of MDA (0.7±0.08). The use of MOLM as an additive in broiler diets reduced lipid oxidation in meat, and maintained the quality of the broiler meat during storage. It also did not have any adverse effects on the growth performance of broilers. Therefore, it has the potential to be used as an additive in broiler diets.
- Full Text:
Effects of pre-slaughter sheep handling and animal-related factors on creatine kinase levels and physico-chemical attributes of mutton
- Authors: Chulayo, Amanda Yucca
- Date: 2012
- Subjects: Sheep -- South Africa , Mutton , Slaughtering and slaughter-houses -- South Africa , Creatine -- Physiological effect
- Language: English
- Type: Thesis , Masters , MSc Agric (Animal Science)
- Identifier: vital:11810 , http://hdl.handle.net/10353/433 , Sheep -- South Africa , Mutton , Slaughtering and slaughter-houses -- South Africa , Creatine -- Physiological effect
- Description: Effects of pre-slaughter sheep handling and animal-related factors on Creatine Kinase levels and physico-chemical attributes of mutton By Chulayo Amanda Yucca The objective of the study was to determine the effects of pre-slaughter sheep handling and animal-related factors on Creatine kinase (CK) levels and physico-chemical characteristics of mutton from South African sheep breeds. One hundred and seventy-three castrated male sheep from four breeds (15 Dormer, 46 South African Mutton Merino, 77 Dorper and 35 Blackhead Persian) were used. The animals were grouped according to age categories. The grouping was as follows: Group 1 (6 ≤ 8 months), Group 2 (9 ≤ 12 months) and Group 3 (13 ≤ 16 months). Blood samples for CK determination were collected at exanguination using disposable vacutainer tubes. Representative samples of the Muscularis longissimuss thoracis et. lumborum (LTL) muscle were taken for the determination of ultimate pH (pHu), colour (L*-lightness, b*- redness and a*- yellowness), thawing and cooking losses and meat tenderness. Significant (P<0.01) breed effects were observed on CK levels with Dormer having the highest CK values. Significant linear relationships were observed between pre-slaughter condition and CK levels. There were positive correlations between colour coordinates L* and b* (r =+0.22) and between a* and b* (r =+0.63). Cooking loss and Warner Braztler Shear Force (WBSF) values were positively correlated (r =+0.29). The Principal Component Analysis (PCA) showed a significant variance for CK and between physico-chemical characteristics of mutton. There were no relationships between CK levels and physico-chemical characteristics of mutton. Significant breed and age effects on pHu, L, a*, b*, thaw %, CL and WBSF of mutton were observed. iv It was concluded that, pre-slaughter conditions affect CK levels and physico-chemical characteristics of mutton. However, there were no relationships between CK levels and physico-chemical characteristics of mutton.
- Full Text:
- Authors: Chulayo, Amanda Yucca
- Date: 2012
- Subjects: Sheep -- South Africa , Mutton , Slaughtering and slaughter-houses -- South Africa , Creatine -- Physiological effect
- Language: English
- Type: Thesis , Masters , MSc Agric (Animal Science)
- Identifier: vital:11810 , http://hdl.handle.net/10353/433 , Sheep -- South Africa , Mutton , Slaughtering and slaughter-houses -- South Africa , Creatine -- Physiological effect
- Description: Effects of pre-slaughter sheep handling and animal-related factors on Creatine Kinase levels and physico-chemical attributes of mutton By Chulayo Amanda Yucca The objective of the study was to determine the effects of pre-slaughter sheep handling and animal-related factors on Creatine kinase (CK) levels and physico-chemical characteristics of mutton from South African sheep breeds. One hundred and seventy-three castrated male sheep from four breeds (15 Dormer, 46 South African Mutton Merino, 77 Dorper and 35 Blackhead Persian) were used. The animals were grouped according to age categories. The grouping was as follows: Group 1 (6 ≤ 8 months), Group 2 (9 ≤ 12 months) and Group 3 (13 ≤ 16 months). Blood samples for CK determination were collected at exanguination using disposable vacutainer tubes. Representative samples of the Muscularis longissimuss thoracis et. lumborum (LTL) muscle were taken for the determination of ultimate pH (pHu), colour (L*-lightness, b*- redness and a*- yellowness), thawing and cooking losses and meat tenderness. Significant (P<0.01) breed effects were observed on CK levels with Dormer having the highest CK values. Significant linear relationships were observed between pre-slaughter condition and CK levels. There were positive correlations between colour coordinates L* and b* (r =+0.22) and between a* and b* (r =+0.63). Cooking loss and Warner Braztler Shear Force (WBSF) values were positively correlated (r =+0.29). The Principal Component Analysis (PCA) showed a significant variance for CK and between physico-chemical characteristics of mutton. There were no relationships between CK levels and physico-chemical characteristics of mutton. Significant breed and age effects on pHu, L, a*, b*, thaw %, CL and WBSF of mutton were observed. iv It was concluded that, pre-slaughter conditions affect CK levels and physico-chemical characteristics of mutton. However, there were no relationships between CK levels and physico-chemical characteristics of mutton.
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Farmers` perceptions of livestock feeding and rangeland management: dynamics of soil, forage and cattle blood serum mineral levels in two communal areas of the Eastern Cape, South Africa
- Authors: Gwelo, Farai Alice
- Date: 2012
- Subjects: Range management -- South Africa -- Eastern Cape , Animal feeding -- South Africa -- Eastern Cape , Livestock -- Breeding -- South Africa -- Eastern Cape , Communal rangelands -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc Agric (Pasture Science)
- Identifier: vital:11581 , http://hdl.handle.net/10353/d1006785 , Range management -- South Africa -- Eastern Cape , Animal feeding -- South Africa -- Eastern Cape , Livestock -- Breeding -- South Africa -- Eastern Cape , Communal rangelands -- South Africa -- Eastern Cape
- Description: This study was conducted to determine livestock production, rangeland management and the mineral levels of soils, grass and cattle blood serum in two communal areas (Kwezana and Dikidikana). A total of 77 farmers from both Kwezana and Dikidikana were interviewed to determine farmers’ perceptions. Soil and grass sampling was done at three sites in each communal area. Soil and grass samples were analysed for N, Ca, Mg, K, P, Fe, Cu, Zn, Mn and Bo. Three, two and half year old Nguni heifers were randomly selected from each communal area and blood samples were collected for the analysis of Ca, Mg, K, Cu and Fe. Soil, grass and blood samples were all collected in two seasons (winter and summer). The results of the study revealed that feed availability was the major constraint in livestock production as indicated by 83 percent of thefarmers at Kwezana and 88 percent at Dikidikana. At both villages less than 20 percent practiced supplementation and grazing management. From both villages, 83 percent of the farmers did not know the forage species preferred by their cattle. The second study revealed significant seasonal variations in soil N in both study areas while forage N exhibited seasonal variations (P<0.05) only at Dikidikana. Spatial variation (P<0.05) in soil Mn was apparent in both seasons at Dikidikana and in summer at Kwezana. At Dikidikana forage P varied (P<0.05) both seasonally and spatially. In both study areas, there was a positive correlation (P<0.05) between soil and forage levels of Cu and Zn. The blood serum of animals from both study areas had higher (P<0.05) K and Na in winter than in summer. Farmers do not understand the composition of their rangelands but are concerned about cattle nutrition during winter. Indeed the mineral status of soils, forages and Nguni cattle blood serum tend to vary not only seasonally but also spatially. There is need therefore to assist the farmers to understand these changes in order to find ways of managing the rangelands in a way that will manipulate both seasonal and spatial variations in soil nutrients for the benefit of the grazing livestock. Further research is required to determine the digestibility of the forages and the amount of energy available from these forages for the grazing livestock.
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- Authors: Gwelo, Farai Alice
- Date: 2012
- Subjects: Range management -- South Africa -- Eastern Cape , Animal feeding -- South Africa -- Eastern Cape , Livestock -- Breeding -- South Africa -- Eastern Cape , Communal rangelands -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc Agric (Pasture Science)
- Identifier: vital:11581 , http://hdl.handle.net/10353/d1006785 , Range management -- South Africa -- Eastern Cape , Animal feeding -- South Africa -- Eastern Cape , Livestock -- Breeding -- South Africa -- Eastern Cape , Communal rangelands -- South Africa -- Eastern Cape
- Description: This study was conducted to determine livestock production, rangeland management and the mineral levels of soils, grass and cattle blood serum in two communal areas (Kwezana and Dikidikana). A total of 77 farmers from both Kwezana and Dikidikana were interviewed to determine farmers’ perceptions. Soil and grass sampling was done at three sites in each communal area. Soil and grass samples were analysed for N, Ca, Mg, K, P, Fe, Cu, Zn, Mn and Bo. Three, two and half year old Nguni heifers were randomly selected from each communal area and blood samples were collected for the analysis of Ca, Mg, K, Cu and Fe. Soil, grass and blood samples were all collected in two seasons (winter and summer). The results of the study revealed that feed availability was the major constraint in livestock production as indicated by 83 percent of thefarmers at Kwezana and 88 percent at Dikidikana. At both villages less than 20 percent practiced supplementation and grazing management. From both villages, 83 percent of the farmers did not know the forage species preferred by their cattle. The second study revealed significant seasonal variations in soil N in both study areas while forage N exhibited seasonal variations (P<0.05) only at Dikidikana. Spatial variation (P<0.05) in soil Mn was apparent in both seasons at Dikidikana and in summer at Kwezana. At Dikidikana forage P varied (P<0.05) both seasonally and spatially. In both study areas, there was a positive correlation (P<0.05) between soil and forage levels of Cu and Zn. The blood serum of animals from both study areas had higher (P<0.05) K and Na in winter than in summer. Farmers do not understand the composition of their rangelands but are concerned about cattle nutrition during winter. Indeed the mineral status of soils, forages and Nguni cattle blood serum tend to vary not only seasonally but also spatially. There is need therefore to assist the farmers to understand these changes in order to find ways of managing the rangelands in a way that will manipulate both seasonal and spatial variations in soil nutrients for the benefit of the grazing livestock. Further research is required to determine the digestibility of the forages and the amount of energy available from these forages for the grazing livestock.
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Perceptions of rural consumers and the quality of mutton at purchase points in the Eastern Cape Province, South Africa
- Authors: Rani, Zikhona Theodora
- Date: 2012
- Subjects: Meat -- Quality , Mutton -- Quality , Consumers' preferences , Quality of products , Consumers -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc Agric (Animal Science)
- Identifier: vital:11823 , http://hdl.handle.net/10353/d1007562 , Meat -- Quality , Mutton -- Quality , Consumers' preferences , Quality of products , Consumers -- South Africa -- Eastern Cape
- Description: The objective of the study was to determine perceptions of rural consumers on mutton quality, and the quality of mutton at purchase points in the Eastern Cape Province, South Africa. The study was conducted in five different municipalities (Buffalo City, Nkonkobe, Ngqushwa, Lukhanje and Amahlathi). A survey was conducted where a sample of 215 consumers were randomly selected and interviewed, either at point of purchase or as they left the shops. The survey was not limited to the shoppers only but also extended to households from the villages. Questions on some of the most important meat quality cues were compiled. The physico-chemical quality of mutton purchased from different shops was also determined. Forty different shops and butcheries selling mutton from all the selected municipalities were visited. Different parts of mutton samples were bought. Physico-chemical qualities of mutton such as colour (L* - lightness, b* - redness and a* - yellowness) and meat pH measurements were taken at points of purchase. Cooking loss and tenderness evaluations were later done at the Meat Science laboratory at the University of Fort Hare. The results indicated that price was one of the major factors affecting the purchasing decisions of consumers. Thirty four percent of the consumers preferred mutton as compared to other protein sources, even though they were not buying this type of meat because it was not affordable to them. Both male and female consumers suggested that more sheep farmers need to be established in order to reduce the levels of imported mutton into South Africa. They also highlighted that selection programmes that will result in efficient sheep production and reduced mutton prices need to be implemented. Meat at points of purchase was affected by season resulting in lower lightness (L*24.7±0.49) values in winter and higher (L* 32.2±0.49) in Spring. The class of shop did not have an effect on meat quality attributes. Trotter had high values of lightness (L*30.4±2.78a), redness (a*30.4±2.78a), yellowness (13.1±1.08a), pH (6.3±0.12a), tenderness (24.9±3.69b) and cooking loss (39.5±4.38ab). The number of days from when the meat was put on the shelves to the time when it was purchased for consumption (days to purchase) had a significant (P<0.05) negative correlation with the Warner Braztler Shear Force (WBSF)values and lightness of the meat. Significant negative (P < 0.05) correlations between pH and colour of the meat (L*, a* and b*) were also observed. It was concluded that rural consumers perceive the quality of mutton as the best and that the physico-chemical quality of meat purchased from different shops was different, largely based on the part of meat, meat storage conditions and not necessarily on the class of the shop.
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- Authors: Rani, Zikhona Theodora
- Date: 2012
- Subjects: Meat -- Quality , Mutton -- Quality , Consumers' preferences , Quality of products , Consumers -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc Agric (Animal Science)
- Identifier: vital:11823 , http://hdl.handle.net/10353/d1007562 , Meat -- Quality , Mutton -- Quality , Consumers' preferences , Quality of products , Consumers -- South Africa -- Eastern Cape
- Description: The objective of the study was to determine perceptions of rural consumers on mutton quality, and the quality of mutton at purchase points in the Eastern Cape Province, South Africa. The study was conducted in five different municipalities (Buffalo City, Nkonkobe, Ngqushwa, Lukhanje and Amahlathi). A survey was conducted where a sample of 215 consumers were randomly selected and interviewed, either at point of purchase or as they left the shops. The survey was not limited to the shoppers only but also extended to households from the villages. Questions on some of the most important meat quality cues were compiled. The physico-chemical quality of mutton purchased from different shops was also determined. Forty different shops and butcheries selling mutton from all the selected municipalities were visited. Different parts of mutton samples were bought. Physico-chemical qualities of mutton such as colour (L* - lightness, b* - redness and a* - yellowness) and meat pH measurements were taken at points of purchase. Cooking loss and tenderness evaluations were later done at the Meat Science laboratory at the University of Fort Hare. The results indicated that price was one of the major factors affecting the purchasing decisions of consumers. Thirty four percent of the consumers preferred mutton as compared to other protein sources, even though they were not buying this type of meat because it was not affordable to them. Both male and female consumers suggested that more sheep farmers need to be established in order to reduce the levels of imported mutton into South Africa. They also highlighted that selection programmes that will result in efficient sheep production and reduced mutton prices need to be implemented. Meat at points of purchase was affected by season resulting in lower lightness (L*24.7±0.49) values in winter and higher (L* 32.2±0.49) in Spring. The class of shop did not have an effect on meat quality attributes. Trotter had high values of lightness (L*30.4±2.78a), redness (a*30.4±2.78a), yellowness (13.1±1.08a), pH (6.3±0.12a), tenderness (24.9±3.69b) and cooking loss (39.5±4.38ab). The number of days from when the meat was put on the shelves to the time when it was purchased for consumption (days to purchase) had a significant (P<0.05) negative correlation with the Warner Braztler Shear Force (WBSF)values and lightness of the meat. Significant negative (P < 0.05) correlations between pH and colour of the meat (L*, a* and b*) were also observed. It was concluded that rural consumers perceive the quality of mutton as the best and that the physico-chemical quality of meat purchased from different shops was different, largely based on the part of meat, meat storage conditions and not necessarily on the class of the shop.
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The effect of moringa oleifera leaf meal on growth perfomance, gut integrity, bone strenght, quality and oxidative stability of meat from broiler chickens
- Authors: Nkukwana, Tobela T
- Date: 2012
- Subjects: Moringa oleifera , Chickens -- Nutrition , Chickens -- Feeding and feeds , Broilers (Chickens)
- Language: English
- Type: Thesis , Doctoral , PhD (Animal Science)
- Identifier: vital:11820 , http://hdl.handle.net/10353/d1006835 , Moringa oleifera , Chickens -- Nutrition , Chickens -- Feeding and feeds , Broilers (Chickens)
- Description: This study was designed was to determine the effects of additive supplementation of Moringa oleifera leaf meal on growth performance, digestibility, digestive organ size, intestinal integrity, bone ash content and bone breaking strength, as well as meat yield and quality of broiler chickens. A total of 2400 day-old unsexed Cobb-500 broiler chicks were randomly allocated to 5 treatment groups: T1, positive control, 668 g/ton Salinomycin and 500 g/ton Albac; T2, T3 and T4 contained graded levels of MOLM at 1 percent, 3 percent and 5 percent of dry matter (DM) intake, respectively; and T5, a negative control (0 percent additives) in a complete randomized design experiment. Except for week one, FI and FCR was highest (P < 0.05) in T4 birds; while T1 birds had the highest FI in the period of 22 to 27d (P < 0.05). Throughout the production period, birds supplemented with MOLM had the highest BW (P < 0.05) than the birds fed the control diets. Feed intake (FI) and feed conversion ratio (FCR) among treatments was highest (P < 0.05) in T4 birds during the period of 8 to 14 d; and was highest (P < 0.05) for T1 birds in the period of 22 to 27d. Protein efficiency ratio (PER) and energy utilization efficiency (EEU) ratios were statistically significant among treatments (P < 0.05). However, dietary treatments had no effect (P > 0.05) on the weights of the heart, liver, spleen, or the gizzard, although the bursa for T2 birds was the lightest (P < 0.05); while gizzard erosion score was highest in T2 birds. All of the nutrients measured, except for fat, had negative intercepts that were significantly different (P < 0.05) from zero, indicating the presence of endogenous fecal losses. Tibiae length (TL) was highest in T2. The dried defatted weight (DW) was heaviest (P < 0.05) for T3 (11.20 ± 0.347) and T5 (11.08 ± 0.328). A positive correlation (r = 0.667; P < 0.01) between TW and DW was observed. There were no dietary effects on bone breaking strength (BBS), but T1 tibiae had highest resistance to breaking force (T1 > T4 > T3 > T2 > T5). Calcium was highest (P < 0.05) in T1; and lowest inT2 and T5. Phosphorus levels were lowest (P < 0.05) in T1; and highest (P < 0.05) in T5 compared. The highest Ca: P ratio was obtained in T4 (P < 0.05); while the ash percent was highest (P < 0.05) in T1. Drip loss increased as L* values increased; and a negative correlation was observed between L* and pH. On D1, C18: 0 and C22 in T2, while C15:0 was highest in T4. On D1, C20:2, C20:3n6 and C22:6n3 were highest in T2 (P < 0.05); T4 had the highest C18:3n6 (P < 0.05), while C20:2 was highest in T5 (P < 0.05). The P/S ratio on D1 was highest in T4; while n-6/n-3 was highest in T1; and n-3 was highest in T3. On D8, the n-3 was highest in T1 (P < 0.05). Results of the current study show that supplementation of M. oleifera leaf at additive levels of up to 5 percent of the bird’s DMI does have the potential to influence the bird performance without any detrimental effects on nutrient utilization, bird health, bone strength and/or meat quality, which can be concluded that MOLM enhanced the bird’s genetic potential for optimal productivity.
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- Authors: Nkukwana, Tobela T
- Date: 2012
- Subjects: Moringa oleifera , Chickens -- Nutrition , Chickens -- Feeding and feeds , Broilers (Chickens)
- Language: English
- Type: Thesis , Doctoral , PhD (Animal Science)
- Identifier: vital:11820 , http://hdl.handle.net/10353/d1006835 , Moringa oleifera , Chickens -- Nutrition , Chickens -- Feeding and feeds , Broilers (Chickens)
- Description: This study was designed was to determine the effects of additive supplementation of Moringa oleifera leaf meal on growth performance, digestibility, digestive organ size, intestinal integrity, bone ash content and bone breaking strength, as well as meat yield and quality of broiler chickens. A total of 2400 day-old unsexed Cobb-500 broiler chicks were randomly allocated to 5 treatment groups: T1, positive control, 668 g/ton Salinomycin and 500 g/ton Albac; T2, T3 and T4 contained graded levels of MOLM at 1 percent, 3 percent and 5 percent of dry matter (DM) intake, respectively; and T5, a negative control (0 percent additives) in a complete randomized design experiment. Except for week one, FI and FCR was highest (P < 0.05) in T4 birds; while T1 birds had the highest FI in the period of 22 to 27d (P < 0.05). Throughout the production period, birds supplemented with MOLM had the highest BW (P < 0.05) than the birds fed the control diets. Feed intake (FI) and feed conversion ratio (FCR) among treatments was highest (P < 0.05) in T4 birds during the period of 8 to 14 d; and was highest (P < 0.05) for T1 birds in the period of 22 to 27d. Protein efficiency ratio (PER) and energy utilization efficiency (EEU) ratios were statistically significant among treatments (P < 0.05). However, dietary treatments had no effect (P > 0.05) on the weights of the heart, liver, spleen, or the gizzard, although the bursa for T2 birds was the lightest (P < 0.05); while gizzard erosion score was highest in T2 birds. All of the nutrients measured, except for fat, had negative intercepts that were significantly different (P < 0.05) from zero, indicating the presence of endogenous fecal losses. Tibiae length (TL) was highest in T2. The dried defatted weight (DW) was heaviest (P < 0.05) for T3 (11.20 ± 0.347) and T5 (11.08 ± 0.328). A positive correlation (r = 0.667; P < 0.01) between TW and DW was observed. There were no dietary effects on bone breaking strength (BBS), but T1 tibiae had highest resistance to breaking force (T1 > T4 > T3 > T2 > T5). Calcium was highest (P < 0.05) in T1; and lowest inT2 and T5. Phosphorus levels were lowest (P < 0.05) in T1; and highest (P < 0.05) in T5 compared. The highest Ca: P ratio was obtained in T4 (P < 0.05); while the ash percent was highest (P < 0.05) in T1. Drip loss increased as L* values increased; and a negative correlation was observed between L* and pH. On D1, C18: 0 and C22 in T2, while C15:0 was highest in T4. On D1, C20:2, C20:3n6 and C22:6n3 were highest in T2 (P < 0.05); T4 had the highest C18:3n6 (P < 0.05), while C20:2 was highest in T5 (P < 0.05). The P/S ratio on D1 was highest in T4; while n-6/n-3 was highest in T1; and n-3 was highest in T3. On D8, the n-3 was highest in T1 (P < 0.05). Results of the current study show that supplementation of M. oleifera leaf at additive levels of up to 5 percent of the bird’s DMI does have the potential to influence the bird performance without any detrimental effects on nutrient utilization, bird health, bone strength and/or meat quality, which can be concluded that MOLM enhanced the bird’s genetic potential for optimal productivity.
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