基于代谢组学分析固体饲料饲喂水平对早期断奶牦牛犊牛皱胃形态与功能发育的影响

Effect of Solid Feed Feeding Levels on Abomasal Morphological and Functional Development in Weaned Yak Calves by Using Metabolomics

试验旨在基于代谢组学技术探究固体饲料饲喂水平对断奶牦牛犊牛皱胃发育的影响。选取21头60日龄左右健康的牦牛公犊牛,分为高饲喂水平组(AL组)、中饲喂水平组(IR70组)和低饲喂水平组(IR40组),每组7头。各组在饲喂等量代乳粉的基础上,分梯度投喂由苜蓿干草和开食料组成的固体饲料。预试期30 d,正试期90 d。待试验结束空腹称重后,每组分别随机选取5头犊牛进行屠宰,采集皱胃组织及内容物样品进行测定与分析。结果表明:①AL组的终末体重、平均日增重、浆膜层厚度显著高于IR70组(P<0.05);IR70组的终末体重、日增重、黏膜上皮厚度、肌层厚度显著高于IR40组(P<0.05);AL组的黏膜上皮、黏膜肌层、肌层、浆膜层厚度显著高于IR40组(P<0.05);IR70组的黏膜肌层厚度显著高于AL组(P<0.05);IR40组的淀粉酶活性显著高于AL组(P<0.05)。②代谢组学分析发现,与IR40组和AL组相比,IR70组在咖啡因代谢途径中,差异代谢物黄嘌呤的含量显著下降(P<0.05)。与AL组相比,IR70组在泛醌等萜类化合物生物合成和叶酸生物合成途径中,差异代谢物4-羟基苯甲酸的含量显著上升(P<0.05)。综上得出,在饲喂代乳粉的基础上提高固体饲料饲喂水平利于牦牛犊牛体重的增长,促进了其早期的健康成长;通过代谢组学发现中饲喂水平提高了牦牛犊牛对营养物质的消化吸收代谢能力,增强了机体的免疫功能,更有利于断奶牦牛犊牛的早期生长发育。

The aim of this experiment was to investigate the effect of solid feed feeding level on the development of abomasum in weaned yak calves based on metabolomics technology.Twenty-one healthy male yak calves around 60 days of age were selected and divided into high feeding level group(AL group),medium feeding level group(IR70 group)and low feeding level group(IR40 group),with 7 calves in each group.The groups were fed a solid diet consisting of alfalfa hay and starter feeding in a gradient based on equal amounts of milk replacer,with the pre-test period of 30 d and a main test period of 90 d.After being weighed on an empty stomach at the end of the test,five calves were randomly selected from each group for slaughter,and samples of abomasum tissues and contents were collected for determination and analysis.The results showed that:①the final body weight,daily weight gain,and mucosal layer thickness were significantly higher in the AL group than in the IR70 group(P<0.05);the final body weight,daily weight gain,mucosal epithelial thickness,and muscular layer thickness were significantly higher in the IR70 group than in the IR40 group(P<0.05);and the thickness of the mucosal epithelium,mucosal muscular layer,muscular layer,and plasma layer were significantly higher in the AL group than in the IR40 group(P<0.05);the thickness of the mucosal muscular layer was significantly higher in the IR70 group than in the AL group(P<0.05);the amylase activity was significantly higher in the IR40 group than in the AL group(P<0.05).②Metabolomics analysis revealed a significant decrease(P<0.05)in the content of the differential metabolite xanthine in the caffeine metabolic pathway in the IR70 group compared with the IR40 and AL group.Compared with the AL group,the IR70 group showed a significant increase in the content of the differential metabolite 4-hydroxybenzoic acid in the terpene biosynthesis,such as ubiquinone,and folate biosynthesis pathways(P<0.05).In summary,it was concluded that increasing the solid feed feeding level on the basis of feeding milk replacer powder was beneficial to the weight gain of yak calves,and promoted their early healthy growth;the metabolomics found that the medium feeding level improved the digestion,absorption and metabolism of nutrients in yak calves,enhanced the immune function,and was more conducive to the early growth and development of weaned yak calves.