Zhu Yanbin, Sun Guangming, Li Xin, Pan Feng, Peng Quanhui
Institute of Animal Science and Veterinary, Tibet Academy of Agriculture and Animal Husbandry Science, Lhasa, China.
Linzhou Animal Husbandry and Veterinary Station, Lhasa, China.
Front Vet Sci. 2023 Jul 21;10:1212422. doi: 10.3389/fvets.2023.1212422. eCollection 2023.
To date, no research has been done on energy requirements for yaks in Tibetan cold weather. The findings of the current study provide proper energy requirements for yaks would facilitate scientific feeding of fattening yaks in cold weather. The metabolomics and 16s rRNA sequencing technologies were used to explore the underlying mechanism that affects the growth performance of yaks fed with different energy levels of diet in cold weather. Three groups of yaks (141.7 ± 3.34 kg) were fed with diets containing metabolizable energy 7.20, 7.89, and 8.58 MJ/kg DM (dry matter) and named the low-, medium-, and high-energy groups, respectively. The results showed that the average daily feed intake of the high-energy group was higher than that of the low-energy group ( = 0.006). Plasma aspartate aminotransferase ( = 0.004), alanine aminotransferase ( < 0.001), and interferon-γ ( < 0.001) in the high-energy group were lower than in the low-energy group. In contrast, superoxide dismutase ( < 0.001), immunoglobulin G ( < 0.001), and interleukin 2 ( = 0.002) were higher than the low-energy group. The rumen microbial protein ( = 0.025), total volatile fatty acids ( = 0.029), and neutral detergent fiber digestibility ( = 0.050) in the high-energy group were higher than in the low-energy group, whereas the acetate: propionate ratio ( = 0.001) and ammonium nitrogen ( = 0.001) were lower than in the low-energy group. The plasma metabolomics results displayed that yaks fed with a high-energy diet augmented the metabolism of arginine, proline, purine, taste transduction, pyrimidine, and glutathione pathways. The relative abundance of in the high-energy group was lower ( < 0.001), whereas the relative abundance of ( < 0.001) was higher than in the low-energy group. The results of the current study suggest that a high-energy diet in growing yaks during the cold season can improve growth performance, rumen microbial protein synthesis, antioxidants, and immunity.
迄今为止，尚未有关于牦牛在西藏寒冷天气下能量需求的研究。本研究结果表明，确定合适的牦牛能量需求将有助于在寒冷天气下对育肥牦牛进行科学饲养。采用代谢组学和16s rRNA测序技术，探索寒冷天气下不同能量水平日粮对牦牛生长性能影响的潜在机制。选取三组体重为（141.7±3.34 kg）的牦牛，分别饲喂代谢能为7.20、7.89和8.58 MJ/kg DM（干物质）的日粮，分别命名为低能量组、中能量组和高能量组。结果表明，高能量组的平均日采食量高于低能量组（P = 0.006）。高能量组血浆天冬氨酸转氨酶（P = 0.004）、丙氨酸转氨酶（P < 0.001）和干扰素-γ（P < 0.001）低于低能量组。相反，超氧化物歧化酶（P < 0.001）、免疫球蛋白G（P < 0.001）和白细胞介素2（P = 0.002）高于低能量组。高能量组瘤胃微生物蛋白（P = 0.025）、总挥发性脂肪酸（P = 0.029）和中性洗涤纤维消化率（P = 0.050）高于低能量组，而乙酸：丙酸比例（P = 0.001）和氨态氮（P = 0.001）低于低能量组。血浆代谢组学结果显示，高能量日粮喂养的牦牛增强了精氨酸、脯氨酸、嘌呤、味觉转导、嘧啶和谷胱甘肽途径的代谢。高能量组[具体菌属名称未给出]的相对丰度较低（P < 0.001），而[具体菌属名称未给出]的相对丰度（P < 0.001）高于低能量组。本研究结果表明，寒冷季节生长牦牛的高能量日粮可提高生长性能、瘤胃微生物蛋白合成、抗氧化能力和免疫力。
