迄今为止,还没有研究过在寒冷天气下牦牛的能量需求。本研究的结果为牦牛提供了适当的能量需求,这将有助于在寒冷天气下科学喂养育肥牦牛。利用代谢组学和16srRNA测序技术探讨了在寒冷天气下不同能量水平饲喂牦牛生长性能影响的潜在机制。三组牦牛(141.7±3.34kg)饲喂含代谢能7.20、7.89和8.58MJ/kgDM(干物质)的饲料,并命名为低,medium-,和高能团体,分别。结果表明,高能组平均日采食量高于低能组(p=0.006)。血浆天冬氨酸转氨酶(p=0.004),丙氨酸氨基转移酶(p<0.001),高能量组的干扰素-γ(p<0.001)低于低能量组。相比之下,超氧化物歧化酶(p<0.001),免疫球蛋白G(p<0.001),白细胞介素2(p=0.002)高于低能量组。瘤胃微生物蛋白(p=0.025),总挥发性脂肪酸(p=0.029),高能组中性洗涤纤维消化率(p=0.050)高于低能组,而乙酸盐:丙酸盐比率(p=0.001)和铵态氮(p=0.001)低于低能量组。血浆代谢组学结果表明,以高能量饮食喂养的牦牛增加了精氨酸的代谢,脯氨酸,嘌呤,味觉转导,嘧啶,和谷胱甘肽途径。高能组的甲氧胺杆菌的相对丰度较低(p<0.001),而甲烷的相对丰度(p<0.001)高于低能量组。目前的研究结果表明,在寒冷季节生长牦牛的高能量饮食可以提高生长性能,瘤胃微生物蛋白质合成,抗氧化剂,和豁免权。
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 (p = 0.006). Plasma aspartate aminotransferase (p = 0.004), alanine aminotransferase (p < 0.001), and interferon-γ (p < 0.001) in the high-energy group were lower than in the low-energy group. In contrast, superoxide dismutase (p < 0.001), immunoglobulin G (p < 0.001), and interleukin 2 (p = 0.002) were higher than the low-energy group. The rumen microbial protein (p = 0.025), total volatile fatty acids (p = 0.029), and neutral detergent fiber digestibility (p = 0.050) in the high-energy group were higher than in the low-energy group, whereas the acetate: propionate ratio (p = 0.001) and ammonium nitrogen (p = 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 Methanobrevibacter in the high-energy group was lower (p < 0.001), whereas the relative abundance of Methanosphaera (p < 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.