摘要
Abstract
This study aimed to analyze the effects of a total mixed ration on the expression of phosphatidylinositol 3-kinase(PI3K)protein and the development of the duodenum in beef cattle.The experiment selected 30 Holstein beef cattle in the fattening period with similar body weight,good health,no diseases,and unified immunization and deworming records.They were randomly divided into two groups with 15 replicates each(each cattle was one replicate).The control group was fed a conventional diet(divided into two phases:day 1～91 and day 92～182,with an average crude protein content of 12.50%).The TMR group was fed a total mixed ration(divided into three phases:day 1～61,day 62～121,and day 122～182,with an average crude protein content of 11.13%).The experimental period lasted 182 days.The results showed that the final weight and net gain of beef cattle in the total mixed diet group were extremely higher than those in the control group(P<0.01),the average daily gain was significantly higher than that in the control group(P<0.05),and the feed-to-gain ratio was extremely lower than that in the control group(P<0.01).The slaughter rate of the total mixed diet group was significantly higher than that of the control group(P<0.05),and the backfat thickness was significantly lower than that of the control group(P<0.05).The duodenal intestinal folds of beef cattle in the total mixed diet feeding group were numerous and tall columnar,the mucosal layer was relatively developed,the outline of mucosal epithelial cells was clearly visible,the lamina propria contained rich microvessels,and the duodenal glands were well-developed.PI3K protein was expressed in the duodenal tissues of beef cattle in both groups.The expression level of PI3K protein in the duodenal tissues of beef cattle in the total mixed diet group was extremely higher than that in the control group(P<0.01).The PI3K protein is mainly expressed in the cytoplasm of mucosal epithelial cells in the mucosal layer,plasma cells in the lamina propria,ductal cells of duodenal glands and vascular endothelial cells.Moreover,the fluorescence intensity of PI3K in the duodenal tissue of beef cattle fed with a total mixed diet is higher than that of the control group.The study indicates that feeding a total mixed ration can improve production performance,slaughter performance,and the expression level of PI3K protein in the duodenum of beef cattle,thereby promoting duodenal function and development.关键词
全混合日粮/肉牛/十二指肠组织/PI3KKey words
Total mixed diet/Beef cattle/Duodenal tissue/PI3K分类
农业科技
