Zhu Yanbin, Sun Guangming, Dunzhu Luosang, Li Xin, Zhaxi Luosang, Zhaxi Suolang, Yangji Cidan, Wangdui Basang, Pan Feng, Peng Quanhui
Institute of Animal Husbandry and Veterinary Medicine, Tibet Academy of Agriculture and Animal Husbandry Science, Lhasa 850009, China.
Linzhou Animal Husbandry and Veterinary Station, Lhasa 850009, China.
Animals (Basel). 2023 Jan 21;13(3):367. doi: 10.3390/ani13030367.
This experiment was aimed to compare the effects of two diets with different protein content on the growth performance, immune indexes, rumen fermentation characteristics and plasma metabolomics of growing yak in the cold season. A total of 24, 2-year-old healthy yaks with similar body weight (142.9 ± 3.56 kg) were randomly allocated to two isoenergetic diets with different protein content (10 vs 14%) according to a non-paired experimental design, and the protein of the diets was increased by increasing soybean meal, rapeseed meal and cottonseed meal. The growth performance experiment lasted 56 days. Four days before the end of the growth experiment, the digestion trial was conducted, and the rumen fluid and plasma was collected for measurement. The results showed that the average daily feed intake ( 0.001) and average daily gain ( = 0.006) of yak fed a high-protein diet was significantly greater, while the feed conversion ratio was lower ( 0.021) than that of yaks fed a low-protein diet. Plasma aspartate aminotransferase ( 0.002), alanine aminotransferase ( 0.001), malondialdehyde ( 0.001), tumor necrosis factor-α ( = 0.032) and interferon-γ ( = 0.017) of the high-protein group were significantly lesser, whereas superoxide dismutase ( = 0.004) and interleukin-2 ( = 0.007) was significantly greater than that of the low-protein group. The rumen microbial crude protein ( < 0.047) and crude protein digestibility ( = 0.015) of yak fed a high-protein diet was significantly greater than that of the low-protein group. The metabolomics results showed that yaks fed a high-protein diet were elevated in protein digestion and absorption, arginine and proline metabolism, tryptophan metabolism, purine metabolism, butanoate metabolism, taste transduction, pyrimidine metabolism, pantothenate and CoA biosynthesis, glutathione metabolism and renin secretion pathways. It is concluded that a high-protein diet in the cold season can promote rumen microbial crude protein synthesis, enhance antioxidant and immune function and promote growth performance of yaks.
本试验旨在比较两种不同蛋白质含量的日粮对寒冷季节生长牦牛生长性能、免疫指标、瘤胃发酵特性及血浆代谢组学的影响。根据非配对试验设计，将24头体重相近（142.9±3.56 kg）的2岁健康牦牛随机分为两种等能量但蛋白质含量不同（10% vs 14%）的日粮组，通过增加豆粕、菜粕和棉粕来提高日粮中的蛋白质含量。生长性能试验持续56天。在生长试验结束前4天进行消化试验，并采集瘤胃液和血浆进行测定。结果表明，采食高蛋白日粮的牦牛平均日采食量（P<0.001）和平均日增重（P = 0.006）显著更高，而饲料转化率（P = 0.021）低于采食低蛋白日粮的牦牛。高蛋白组血浆天冬氨酸转氨酶（P<0.002）、丙氨酸转氨酶（P<0.001）、丙二醛（P<0.001）、肿瘤坏死因子-α（P = 0.032）和干扰素-γ（P = 0.017）显著更低，而超氧化物歧化酶（P = 0.004）和白细胞介素-2（P = 0.007）显著高于低蛋白组。采食高蛋白日粮的牦牛瘤胃微生物粗蛋白（P<0.047）和粗蛋白消化率（P = 0.015）显著高于低蛋白组。代谢组学结果表明，采食高蛋白日粮的牦牛在蛋白质消化吸收、精氨酸和脯氨酸代谢、色氨酸代谢、嘌呤代谢、丁酸代谢、味觉转导、嘧啶代谢、泛酸和辅酶A生物合成、谷胱甘肽代谢和肾素分泌途径方面有所升高。结论是，寒冷季节高蛋白日粮可促进牦牛瘤胃微生物粗蛋白合成，增强抗氧化和免疫功能，促进生长性能。
