Wang Guoxiu, Zhang Qian, Chen Zhanyu, Huang Yongliang, Wang Weimin, Zhang Xiaoxue, Jia Jiale, Gao Qihao, Xu Haoyu, Li Chong
College of Animal Science and Technology, Gansu Agricultural University, Lanzhou 730070, China.
Institute of Grassland Research of Chinese Academy of Agricultural Sciences, Hohhot 010000, China.
Animals (Basel). 2023 May 24;13(11):1733. doi: 10.3390/ani13111733.
Although early feeding strategies influence intestinal development, the effects of milk replacer (MR) feeding level on intestinal structure and functional development and underlying regulatory mechanisms remain unclear. In this study, 14 male Hu lambs were fed MR at 2% or 4% of their average body weight and weaned at 35 days of age. The MR was produced by the Institute of Feed Research of the Chinese Academy of Agricultural Sciences, and it contains 96.91% dry matter, 23.22% protein, and 13.20% fat. Jejunal tissues were assessed by RNA-seq for differences in the gene expression of lambs at 49 days of age; regulatory pathways and mechanisms of the effects of early nutrition on intestinal function and development were analyzed, along with growth performance, feed intake, jejunal histomorphology, and digestive enzyme activities. Increasing MR- feeding levels increased dry matter intake and daily gain before weaning, as well as lactase, amylase, lipase, trypsin, and chymotrypsin activities and intestinal villus length and muscular thickness. Overall, 1179 differentially expressed genes were identified, which were enriched in nutrient metabolism, coagulation cascades, and other pathways. Further, intensive MR feeding affected insulin sensitivity to reduce excessive glucose interception by intestinal tissues to ensure adequate absorbed glucose release into the portal circulation and promoted lipid and protein degradation in intestinal tissues to meet the energy demand of intestinal cells by regulating , , , , and expression.
尽管早期喂养策略会影响肠道发育，但代乳粉（MR）喂养水平对肠道结构和功能发育及其潜在调控机制的影响仍不清楚。在本研究中，14只雄性湖羊羔羊按其平均体重的2%或4%饲喂代乳粉，并在35日龄时断奶。代乳粉由中国农业科学院饲料研究所生产，其干物质含量为96.91%，蛋白质含量为23.22%，脂肪含量为13.20%。通过RNA测序评估49日龄羔羊空肠组织的基因表达差异；分析早期营养对肠道功能和发育影响的调控途径和机制，以及生长性能、采食量、空肠组织形态和消化酶活性。提高代乳粉喂养水平会增加断奶前的干物质摄入量和日增重，以及乳糖酶、淀粉酶、脂肪酶、胰蛋白酶和糜蛋白酶的活性，还会增加肠绒毛长度和肌层厚度。总体而言，共鉴定出1179个差异表达基因，这些基因富集在营养代谢、凝血级联反应等途径中。此外，高强度代乳粉喂养会影响胰岛素敏感性，减少肠道组织对过多葡萄糖的截留，以确保足够的吸收葡萄糖释放到门静脉循环中，并通过调节 、 、 、 和 的表达促进肠道组织中的脂质和蛋白质降解，以满足肠道细胞的能量需求。
