Kayima Denis, Slayi Mhlangabezi, Jaja Ishmael Festus, Mapiye Cletos, Dzama Kennedy
Livestock & Pasture Science Department, Faculty of Science & Agriculture, University of Fort Hare, Alice, South Africa.
Risk and Vulnerability Science Centre, University of Fort Hare, Alice, South Africa.
J Adv Vet Anim Res. 2024 Jun 8;11(2):349-355. doi: 10.5455/javar.2024.k783. eCollection 2024 Jun.
This study aimed to evaluate rumen fermentation parameters influenced by both grazing system and breed.
A 2 × 2 factorial design was employed, involving 40 cows with matched age, parity, and physiological status. The cows were evenly divided between Bonsmara and Nguni breeds, as well as communal and commercial grazing systems. Rumen fluid samples were collected and analyzed for parameters including ammonia-nitrogen (NH3-N), pH, temperature, and volatile fatty acids (VFAs).
Nguni cows exhibited significantly higher ruminal NH3-N levels ( 0.05) compared to Bonsmara, ranging from 69.05 to 96.78 mg/l. Commercial grazing demonstrated significantly higher NH3-N concentrations ( 0.05) than communal grazing. Ruminal pH, temperature, total VFAs, and specific VFAs (Iso-butyrate, valeric, and iso-valeric) did not show significant differences ( 0.05). However, total VFAs were slightly lower in communal grazing (78.87 mmol/l) than in commercial grazing (89.80 mmol/l). Acetate, propionate, butyrate, and the acetate to propionate ratio did not display significant differences ( 0.05) between breeds but varied between grazing systems. Communal systems had higher acetate and acetate to propionate ratio ( 0.05), while commercial systems showed higher propionate and butyrate levels ( 0.05).
Grazing conditions significantly influenced rumen fermentation parameters, irrespective of breed. Further research is necessary to explore the relationship between forage conditions, diversity, and rumen fermentation within different grazing systems.
本研究旨在评估放牧系统和品种对瘤胃发酵参数的影响。
采用2×2析因设计，涉及40头年龄、胎次和生理状态匹配的奶牛。奶牛被均匀分为邦斯玛拉和恩古尼两个品种，以及公共放牧和商业放牧系统。采集瘤胃液样本并分析氨氮（NH3-N）、pH值、温度和挥发性脂肪酸（VFA）等参数。
恩古尼奶牛的瘤胃NH3-N水平显著高于邦斯玛拉奶牛（P<0.05），范围为69.05至96.78毫克/升。商业放牧的NH3-N浓度显著高于公共放牧（P<0.05）。瘤胃pH值、温度、总挥发性脂肪酸和特定挥发性脂肪酸（异丁酸、戊酸和异戊酸）没有显著差异（P>0.05）。然而，公共放牧的总挥发性脂肪酸（78.87毫摩尔/升）略低于商业放牧（89.80毫摩尔/升）。乙酸、丙酸、丁酸以及乙酸与丙酸的比例在品种之间没有显著差异（P>0.05），但在放牧系统之间有所不同。公共放牧系统中的乙酸和乙酸与丙酸比例较高（P<0.05），而商业放牧系统中的丙酸和丁酸水平较高（P<0.05）。
放牧条件对瘤胃发酵参数有显著影响，与品种无关。有必要进一步研究不同放牧系统中饲料条件、多样性与瘤胃发酵之间的关系。
