Zhang Chenyang, La YongFu, Ma Xiaoming, Zhandui Pingcuo, Wu Xiaoyun, Guo Xian, Yan Ping, Dunzhu Luosan, Liang Chunnian
Key Laboratory of Yak Breeding Engineering of Gansu Province, Lanzhou Institute of Husbandry and Pharmaceutical Sciences of Chinese Academy of Agricultural Sciences, Lanzhou, China.
Key Laboratory of Animal Genetics and Breeding on Tibetan Plateau, Ministry of Agriculture and Rural Affairs, Lanzhou, China.
Front Microbiol. 2024 Dec 11;15:1491551. doi: 10.3389/fmicb.2024.1491551. eCollection 2024.
Yak () is a large ruminant endemic to the Tibetan plateau. The addition of enzyme complexes to feed can significantly improve their growth performance. Therefore, studying the effects of ruminant compound enzyme preparations dosage on yak rumen microorganisms and production performance is crucial to promoting the development of the yak industry. This study aimed to determine the effects of feeding yaks with different doses of ruminant enzyme compounds on the performance, meat quality, and rumen microorganisms of yaks. Three kinds of experimental diets with doses of 0.5 g/kg (LE group), 1 g/kg (ME group), and 2 g/kg (HE group) were selected to determine the growth index, meat quality, serum biochemical indexes, rumen fluid pH and other indexes of the three experimental groups. Metagenomics studies were used to investigate the differences in rumen microbial composition and function among yak groups, and transcriptome sequencing of the longest dorsal muscle was performed to reveal the expression of differential genes among different groups. It was determined that the levels of dietary enzyme complexes significantly affected growth performance, rumen fluid pH, and serum biochemical indices. At the phylum level, the dominant phylum in all three treatment groups was Bacteroidota, Bacillota, Kiritimatiellota, and Pseudomonadota. At the genus level, Prevotella, Methanobrevibacter, Oscillibacter. Fibrobacter showed statistically significant differences in abundance ( < 0.05). CAZymes family analysis revealed significant differences in GHs, CTs, and CEs among the three groups. Genome-wide differential gene expression in the longest muscle of the yak back was analyzed by RNA-seq between the three experimental groups. Some DEGs were found to be enriched in the ECM, PI3K-Akt, PPAR, and protein digestion and absorption receptor pathways. Combined metagenomics and transcriptomics analyses revealed that some microorganisms were significantly associated with the genes COL11A1, POSTN, and PTHLH, which are involved in growth metabolism. In summary, this study investigated the effects and interrelationships of ruminant complex enzymes on yak performance, meat quality, and rumen environment. The results of this study provide a scientific basis for adding ruminant enzymes to yaks.
牦牛是青藏高原特有的大型反刍动物。在饲料中添加复合酶制剂可显著提高其生长性能。因此，研究反刍动物复合酶制剂用量对牦牛瘤胃微生物和生产性能的影响，对推动牦牛产业发展至关重要。本研究旨在确定给牦牛饲喂不同剂量反刍动物酶复合物对牦牛生产性能、肉质和瘤胃微生物的影响。选取剂量为0.5 g/kg（低酶组，LE组）、1 g/kg（中酶组，ME组）和2 g/kg（高酶组，HE组）的三种试验日粮，测定三个试验组的生长指标、肉质、血清生化指标、瘤胃液pH值等指标。采用宏基因组学研究方法探究牦牛组间瘤胃微生物组成和功能的差异，并对最长背肌进行转录组测序，以揭示不同组间差异基因的表达情况。结果表明，日粮复合酶水平显著影响生长性能、瘤胃液pH值和血清生化指标。在门水平上，三个处理组中的优势门均为拟杆菌门、芽孢杆菌门、基里蒂马蒂埃洛菌门和变形菌门。在属水平上，普雷沃氏菌属、甲烷短杆菌属、颤杆菌属、纤维杆菌属的丰度存在统计学显著差异（P<0.05）。碳水化合物活性酶（CAZymes）家族分析显示，三组之间糖苷水解酶（GHs）、碳水化合物酯酶（CTs）和纤维素酶（CEs）存在显著差异。通过RNA测序分析了三个试验组牦牛背部最长肌的全基因组差异基因表达。发现一些差异表达基因在细胞外基质（ECM）、磷脂酰肌醇-3激酶-蛋白激酶B（PI3K-Akt）、过氧化物酶体增殖物激活受体（PPAR）和蛋白质消化吸收受体途径中富集。宏基因组学和转录组学联合分析表明，一些微生物与参与生长代谢的基因Ⅰ型胶原蛋白α1链（COL11A1）、骨桥蛋白（POSTN）和甲状旁腺激素样蛋白（PTHLH）显著相关。综上所述，本研究探究了反刍动物复合酶对牦牛生产性能、肉质和瘤胃环境的影响及相互关系。本研究结果为牦牛添加反刍动物酶提供了科学依据。
