Effects Of Chlorogenic Acid On Production Performance And Intestinal Barrier Of Meat Rabbits

The aim of this experiment was to investigate the effect of chlorogenic acid(CGA)on the productive performance and intestinal barrier of weaned meat rabbits.In this experiment,160 weaned meat rabbits were selected and randomly divided into four treatment groups with 40 replicates each,one for each replicate.The control group was fed the basal diet and the chlorogenic acid(CGA)group was fed diets with 400,800 and 1600 mg/kg chlorogenic acid added to the basal diet for 35 d.The results of the experiment were as follows.(1)The effect of chlorogenic acid on the growth and development of meat rabbits.Compared to the control group,the CGA800 group had a significant increase in the final body weight and average daily gain in weaned meat rabbits(P < 0.05).Although there was a significant decrease in feed-to-weight ratio(P < 0.05),there was no significant effect on the average daily feed intake(P > 0.05).The chlorogenic acid groups had no significant effect on the diarrhea rate and mortality of weaned meat rabbits compared to the control group(P > 0.05).The CGA400 and CGA800 groups had a significant increase in the full net bore weight and half net bore weight of weaned meat rabbits(P < 0.05).The thymus index of weaned meat rabbits in the CGA400 and CGA800 groups had a highly significant increase(P < 0.01).The 24-hour p H value of weaned meat rabbit muscles in the CGA800 and CGA1600 groups had a significant increase(P < 0.05).The muscle redness a* of weaned meat rabbit muscles in the CGA400 and CGA800 groups had a significant increase after 45 minutes(P < 0.05).The muscle shear force of weaned meat rabbit muscles in the CGA400 and CGA800 groups had a significant decrease(P < 0.05).The serum total protein of weaned meat rabbits in the CGA400 and CGA1600 groups had a highly significant increase(P < 0.01).The serum album of weaned rabbits in the chlorogenic acid groups significantly increased(P < 0.01).(2)The effect of chlorogenic acid on the physical barrier of the intestinal tract of meat rabbits.Compared to the control group,the chlorogenic acid groups significantly reduced the crypt depth of the jejunum(P<0.05).The CGA800 and CGA1600 groups significantly increased the V/C value of the jejunum and ileum(P<0.05).The CGA400 and CGA800groups significantly increased the gene expression of Occludin,ZO-1,and jejunal ZO-1 in the duodenum(P<0.05).The CGA1600 group significantly increased the gene expression of Occludin in the ileum(P<0.05).The chlorogenic acid groups significantly increased the gene expression of ZO-2 in the duodenum and Claudin-1 in the ileum compared to the control group(P<0.05).(3)The effect of chlorogenic acid on the chemical barrier of the intestinal tract of meat rabbits.Compared to the control group,the chlorogenic acid groups significantly reduced the serum DAO activity and D-LA level(P < 0.05).The CGA1600 group significantly reduced the serum LPS content(P < 0.05).The CGA800 group significantly increased the duodenal TGF-α content and jejunal DAO activity(P < 0.05).The CGA1600 group significantly increased the ileal TGF-α content and DAO activity(P < 0.05).The CGA800 group significantly increased the sucrase,maltase,and jejunal alkaline phosphatase activity(P < 0.05).The CGA800 and CGA1600 groups significantly increased the ileal maltase activity(P < 0.05).The CGA400 and CGA800 groups significantly increased the duodenal lactase activity(P < 0.05).The CGA400 group significantly increased the jejunal lactase activity(P < 0.05).(4)The effect of chlorogenic acid on the immune barrier of the intestinal tract of meat rabbits.Compared to the control group,the chlorogenic acid groups significantly reduced the serum IL-1β content(P < 0.05).The CGA800 and CGA1600 groups significantly reduced the serum IL-6 content(P < 0.05).The CGA1600 group significantly reduced the serum TNF-α content(P < 0.05).The CGA800 group significantly increased the duodenal IL-10 content(P < 0.05).The CGA800 and CGA1600 groups significantly increased the jejunal IL-10 content(P < 0.05).Compared to the CGA400 and CGA800 groups,the CGA1600 group significantly increased the ileal SIg A content(P < 0.05).(5)The effect of chlorogenic acid on the microbial barrier of the intestinal tract of meat rabbits.The results of 16 S r RNA high-throughput sequencing showed that chlorogenic acid increased the microbial diversity and richness of the cecum content(P < 0.05),and increased the abundance of butyrate-producing bacteria(including V9D2013＿group,Monoglobus,Papillibacter and UCG-005)(P < 0.05).(6)Effect of chlorogenic acid on the expression of intestinal nutrient transport factors in meat rabbits.Compared to the control group,the CGA800 group significantly increased the gene expression of GLUT2 in the duodenum(P < 0.05).The CGA400 and CGA800 groups significantly increased the gene expression of ZNT1 and GLUT2 in the jejunum(P <0.05).(7)Effect of chlorogenic acid on intestinal antioxidant activity in meat rabbits.Compared to the control group,the CGA400 and CGA800 groups significantly reduced the serum MDA content(P < 0.05).The CGA800 group significantly increased the duodenal CAT and GSH-Px activity(P < 0.05).The chlorogenic acid groups significantly increased the ileal CAT activity(P < 0.05).The CGA1600 group significantly increased the ileal T-AOC content,T-SOD activity,and Nrf2 gene expression(P < 0.05).The CGA800 and CGA1600 groups significantly increased the ileal HO-1 gene expression(P < 0.05).In summary,adding chlorogenic acid to the diet can increase the digestive enzyme activity,improve inflammatory factors,enhance antioxidant capacity,regulate the composition and diversity of intestinal microbiota,maintain intestinal barrier function,and improve the production performance of weaned meat rabbits.According to the growth and development performance of this experiment,the optimal addition amount of chlorogenic acid is 800 mg/kg.