Effect of grazing systems and age on enteric methane production and performance plus grazing system effect on ruminal fermentation parameters of Nguni and Bonsmara beef cows
- Authors: Kayima, Denis
- Date: 2021-09
- Subjects: Grazing , Pastures--Management , Ruminants--Feeding and feeds
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20583 , vital:46153
- Description: Beef breeds of cattle are predominantly raised through extensive grazing and produce the highest levels of enteric methane (CH4) through ruminal fermentation. The objective of this study was to evaluate the effect of breed, grazing, and age on enteric methane production and performance of beef cows as well as effect of breed and grazing system on ruminal fermentation parameters. Two separate studies were conducted; the first study evaluated the effect of grazing system, breed, and age on ruminal enteric methane production and performance of selected beef breeds. The second study evaluated the effect of the grazing system and breed on ruminal fermentation. In the first study, two breeds (Nguni and Bonsmara) raised under two grazing systems (communal and commercial) in a random complete block design were grouped into 3 age categories. Eighty-four cows aged between 24-120 months were randomly selected and grouped by age: group A (young adult cow, n = 7, 24-48 months old), group B (adult, n = 7, 60-80 months old), and group C (old adult, n = 7, 90-120 months) in either grazing system. Data were collected on methane production per day, body condition, and weight used to estimate dry matter intake (DMI), methane per DMI, and methane per body weight. In the second study, 40 cows of the same age group, parity, and physiological status were used. Ten cows per breed (Bonsmara and Nguni) in either grazing system (communal and commercial) were used in a random complete block design. Rumen fluid collection was done by the stomach tube method. Data were collected on ruminal ammonia-nitrogen (NH3-N), pH, Temperature, volatile fatty acids (VFAs). Older animals produced higher methane per head in the order of C > B > A; (P<0.0001). Performance parameters like Body condition score (BCS), body weight (BW), dry matter intake (DMI), and daily methane were higher (P<0.05) in Bonsmara. However, Methane per BW was higher in Nguni (P<0.05), and methane per DMI did not differ among breeds (P>0.05). Body condition, BW, and DMI were higher (P<0.05) in commercial grazing system. Contrary, daily methane production, methane production per DMI, and methane produced per BW were higher in communal grazing. In the second study, Ruminal NH3-N concentration ranged between 69.05 - 96.78 mg/L and was higher (P<0.05) in Nguni. It was also higher (P<0.05) in the commercial grazing system. Ruminal pH, temperature, total VFAs, and certain individual VFAs (iso-butyrate, valeric and iso-valeric) did not differ (P>0.05) among breeds and grazing systems. However, total VFAs were slightly lower in communal grazing (78.87 mmol/L) than commercial grazing (89.80 mmol/L). Acetate, propionate, butyrate proportions, and acetate to propionate ratio did not differ (P>0.05) among breeds but differed (P<0.05) between grazing systems. Acetate (P<0.05) and acetate to propionate ratio (P<0.05) were higher in the communal grazing system, while the reverse was true for propionate (P<0.05) and butyrate (P<0.05). Bonsmara produced more methane than Nguni under similar conditions, with Nguni uniquely producing more methane per BW, indicating host genetics influence. Communal animals and older animals produced more CH4 than commercial and younger cows regardless of the breed, indicating ruminal inefficiencies in very old cows. These results emphasize the idea that host genetics or breed, grazing system, and age influence methane output and performance. Hence, breeding strategies for hard-to-measure traits like methane production need to put all these factors into consideration. , Thesis (MSc) (Animal Science) -- University of Fort Hare, 2021
- Full Text:
- Authors: Kayima, Denis
- Date: 2021-09
- Subjects: Grazing , Pastures--Management , Ruminants--Feeding and feeds
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10353/20583 , vital:46153
- Description: Beef breeds of cattle are predominantly raised through extensive grazing and produce the highest levels of enteric methane (CH4) through ruminal fermentation. The objective of this study was to evaluate the effect of breed, grazing, and age on enteric methane production and performance of beef cows as well as effect of breed and grazing system on ruminal fermentation parameters. Two separate studies were conducted; the first study evaluated the effect of grazing system, breed, and age on ruminal enteric methane production and performance of selected beef breeds. The second study evaluated the effect of the grazing system and breed on ruminal fermentation. In the first study, two breeds (Nguni and Bonsmara) raised under two grazing systems (communal and commercial) in a random complete block design were grouped into 3 age categories. Eighty-four cows aged between 24-120 months were randomly selected and grouped by age: group A (young adult cow, n = 7, 24-48 months old), group B (adult, n = 7, 60-80 months old), and group C (old adult, n = 7, 90-120 months) in either grazing system. Data were collected on methane production per day, body condition, and weight used to estimate dry matter intake (DMI), methane per DMI, and methane per body weight. In the second study, 40 cows of the same age group, parity, and physiological status were used. Ten cows per breed (Bonsmara and Nguni) in either grazing system (communal and commercial) were used in a random complete block design. Rumen fluid collection was done by the stomach tube method. Data were collected on ruminal ammonia-nitrogen (NH3-N), pH, Temperature, volatile fatty acids (VFAs). Older animals produced higher methane per head in the order of C > B > A; (P<0.0001). Performance parameters like Body condition score (BCS), body weight (BW), dry matter intake (DMI), and daily methane were higher (P<0.05) in Bonsmara. However, Methane per BW was higher in Nguni (P<0.05), and methane per DMI did not differ among breeds (P>0.05). Body condition, BW, and DMI were higher (P<0.05) in commercial grazing system. Contrary, daily methane production, methane production per DMI, and methane produced per BW were higher in communal grazing. In the second study, Ruminal NH3-N concentration ranged between 69.05 - 96.78 mg/L and was higher (P<0.05) in Nguni. It was also higher (P<0.05) in the commercial grazing system. Ruminal pH, temperature, total VFAs, and certain individual VFAs (iso-butyrate, valeric and iso-valeric) did not differ (P>0.05) among breeds and grazing systems. However, total VFAs were slightly lower in communal grazing (78.87 mmol/L) than commercial grazing (89.80 mmol/L). Acetate, propionate, butyrate proportions, and acetate to propionate ratio did not differ (P>0.05) among breeds but differed (P<0.05) between grazing systems. Acetate (P<0.05) and acetate to propionate ratio (P<0.05) were higher in the communal grazing system, while the reverse was true for propionate (P<0.05) and butyrate (P<0.05). Bonsmara produced more methane than Nguni under similar conditions, with Nguni uniquely producing more methane per BW, indicating host genetics influence. Communal animals and older animals produced more CH4 than commercial and younger cows regardless of the breed, indicating ruminal inefficiencies in very old cows. These results emphasize the idea that host genetics or breed, grazing system, and age influence methane output and performance. Hence, breeding strategies for hard-to-measure traits like methane production need to put all these factors into consideration. , Thesis (MSc) (Animal Science) -- University of Fort Hare, 2021
- Full Text:
Characterisation of communal rangeland degradation and evaluation of vegetation restoration techniques in the Eastern Cape, South Africa
- Authors: Lesoli, 'Mota Samuel
- Date: 2011-12
- Subjects: Communal rangelands , Grazing
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/24316 , vital:62624
- Description: This study assessed the social factors influencing poor communal rangeland management, which are assumed to result in rangeland degradation. This was followed by, examination of biophysical characteristics of rangeland degradation in communal areas. To relate social factors featuring in communal rangeland management with rangeland degradation, biophysical factors influencing livestock grazing distribution patterns were studied. To establish the solution to communal rangeland degradation, rangeland restoration techniques were evaluated. The study was conducted at Amakhuze Tribal Authority (ATA) (S32o 38´, E26o56, 763 - 1500 m.a.s.l) composed of six villages and Phandulwazi Agricultural High School (S32o 39´ and E26o 55´, 747 m.a.s.l). Focus group discussions were conducted in six villages and questionnaire surveys in four randomly selected villages to assess social factors influencing communal rangeland degradation. Communal rangeland degradation biophysical characteristics were assessed. Biophysical factors affecting livestock grazing distribution pattern were examined through direct field observations for 12 months. Restoration techniques were evaluated on 26 plots. The social factors influencing communal rangeland management include lack of skills on rangeland management for farmers, lack of individual/community obligation on grazing management, lack of effective policies and/or poor enforcement accompanied by lack of effective institutions governing rangeland utilisation and management. Communal rangelands were more (χ 2 = 2612.07, df = 26, p < 0.01) degraded compared with controlled grazing areas. Within the communal rangelands, land degradation was higher at the low-lying areas, compared to foothills, midslopes, and mountaintop (crest). Rangeland degradation in communal areas was characterised by poor forage productivity and poor vegetation cover , higher soil unconfined compressive strength (UCS) (4.5 kg/cm2) with low hydraulic conductivity (5.21 x 10-3) and physical soil loss characteristics such presence of terracettes, pedestals, rills and gullies. Grazing distribution was higher at valley bottom (r2 = 0.404, p < 0.001), low altitude (r2 = -0.007, p < 0.001), closer to water points (r2 = -0.001, p < 0.001), and on grassland vegetation (r2 = 0.620, p < 0.001). Introduction of seedlings with microcatchment combined with brushpack promoted (p < 0.05) higher number of tillers (13), leaves (42) and reduced seedling mortality (10.4percent). T. triandra produced higher (p < 0.05) number of tillers (12) and leaves (39) but low number of inflorescence (0.7) with higher mortality rates (25.3percent) compared to P. dilatatum. Where plant propagules were introduced as seeds, use of microcatchment promoted higher seed germination (F = 38.84, p < 0.05) and maintained higher plant density (F = 37.43, p < 0.05). E. curvula seeds attained higher germination rate and maintained higher plant density compared to D. eriantha and P. Maximum. Use of microcatchment, brushpack, and water spreading system promoted soil water retention. It is important that any interventions aimed at improving communal rangeland management, controlling rangeland degradation in the communal areas, or restoring degraded rangelands to consider the social factors driving rangeland management and biophysical factors influencing grazing distribution pattern. Rangeland restoration techniques for communal areas should be centred on their ability to collect and retain water to promote restoration performance of introduced plant propagules. , Thesis (PhD) -- Faculty of Science and Agriculture, 2011
- Full Text:
- Authors: Lesoli, 'Mota Samuel
- Date: 2011-12
- Subjects: Communal rangelands , Grazing
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/24316 , vital:62624
- Description: This study assessed the social factors influencing poor communal rangeland management, which are assumed to result in rangeland degradation. This was followed by, examination of biophysical characteristics of rangeland degradation in communal areas. To relate social factors featuring in communal rangeland management with rangeland degradation, biophysical factors influencing livestock grazing distribution patterns were studied. To establish the solution to communal rangeland degradation, rangeland restoration techniques were evaluated. The study was conducted at Amakhuze Tribal Authority (ATA) (S32o 38´, E26o56, 763 - 1500 m.a.s.l) composed of six villages and Phandulwazi Agricultural High School (S32o 39´ and E26o 55´, 747 m.a.s.l). Focus group discussions were conducted in six villages and questionnaire surveys in four randomly selected villages to assess social factors influencing communal rangeland degradation. Communal rangeland degradation biophysical characteristics were assessed. Biophysical factors affecting livestock grazing distribution pattern were examined through direct field observations for 12 months. Restoration techniques were evaluated on 26 plots. The social factors influencing communal rangeland management include lack of skills on rangeland management for farmers, lack of individual/community obligation on grazing management, lack of effective policies and/or poor enforcement accompanied by lack of effective institutions governing rangeland utilisation and management. Communal rangelands were more (χ 2 = 2612.07, df = 26, p < 0.01) degraded compared with controlled grazing areas. Within the communal rangelands, land degradation was higher at the low-lying areas, compared to foothills, midslopes, and mountaintop (crest). Rangeland degradation in communal areas was characterised by poor forage productivity and poor vegetation cover , higher soil unconfined compressive strength (UCS) (4.5 kg/cm2) with low hydraulic conductivity (5.21 x 10-3) and physical soil loss characteristics such presence of terracettes, pedestals, rills and gullies. Grazing distribution was higher at valley bottom (r2 = 0.404, p < 0.001), low altitude (r2 = -0.007, p < 0.001), closer to water points (r2 = -0.001, p < 0.001), and on grassland vegetation (r2 = 0.620, p < 0.001). Introduction of seedlings with microcatchment combined with brushpack promoted (p < 0.05) higher number of tillers (13), leaves (42) and reduced seedling mortality (10.4percent). T. triandra produced higher (p < 0.05) number of tillers (12) and leaves (39) but low number of inflorescence (0.7) with higher mortality rates (25.3percent) compared to P. dilatatum. Where plant propagules were introduced as seeds, use of microcatchment promoted higher seed germination (F = 38.84, p < 0.05) and maintained higher plant density (F = 37.43, p < 0.05). E. curvula seeds attained higher germination rate and maintained higher plant density compared to D. eriantha and P. Maximum. Use of microcatchment, brushpack, and water spreading system promoted soil water retention. It is important that any interventions aimed at improving communal rangeland management, controlling rangeland degradation in the communal areas, or restoring degraded rangelands to consider the social factors driving rangeland management and biophysical factors influencing grazing distribution pattern. Rangeland restoration techniques for communal areas should be centred on their ability to collect and retain water to promote restoration performance of introduced plant propagules. , Thesis (PhD) -- Faculty of Science and Agriculture, 2011
- Full Text:
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