Effects Of Chicory Fiber On Reproductive Performance And Intestinal Health Of SD Rats

Adding suitable dietary fiber to the diet can improve the reproductive performance of sows.Indeed,there exist various problems in the application of traditional dietary fibers（e.g.,rice bran,corn husks,bran,oat husks and alfalfa flour）,including high insoluble fiber content and anti-nutritional factor level,and casuing mycotoxin contamination.Therefore,it is urgent to develop safe and effective dietary fiber additives in live-stock cultivation.Chicory fiber（CF）contains a large amount of fructan and is an ideal source of dietary fiber feed;however,its effects on the reproductive performance and intestinal health of pregnant animals still need to be investigated.In this study,based on the analysis of nutritional content and sugar content of CF,the Sprague Dawley（SD）pregnancy rat model was used to evaluate the effects of CF on reproductive performance,intestinal barrier function and intestinal microbiota composition,providing theorectical basis for the application of CF in sows.The specific content and results of the study are as follows:1、Analysis of nutritional components of chicory fiberHere,the contents of conventional nutrients（crude protein,crude fat,moisture,crude ash,crude fiber,and nitrogen-free extracts）and sugar composition（monosaccharides,disaccharides,and fructan）in CF were detected according to the national standards.The results indicated that CF including 6.06%crude protein,0.55%crude fat,8.30%moisture,8.84%crude fiber,and 72.14%nitrogen-free extract.In addition,CF contains a large amount of fructan（60.10%）and a small amount of monosaccharides（4.15%fructose）and disaccharides（5.72%sucrose）.Generally,CF is a fiber feed material containing a large amount of fructan.2、Effect of chicory fiber on reproductive performance of SD ratsSD rats were used as the research object to explore the effect of dietary supplementation with different levels of CF on the reproductive performance.Forty SD rats were selected and randomly divided into 4 groups[Control group（basic diet）,5%CF group（basic diet+5%CF）,10%CF group（basic diet+10%CF）and 15%CF group（basic diet+15%CF）]with 10 replicates in each group and one in each.The rats were acclimated for 3 days,and the experimental period was 39 days（pregnancy 18 d+lactation 21 d）.The female rats were dissected and sampled after the experiment.The results showed that:（1）Compared with the control group,diet supplemented with different levels of CF significantly increased the number born alive and total litter birth weight of offspring（P<0.05）;10%CF（P<0.01）and 15%CF（P<0.05）significantly reduced the weight variable coefficient of littermates;and lowered the ADFI.（2）The results of regression equation showed that the optimal dietary addition level of CF in pregnant rats was 10%.（3）Compared with the control group,the urea nitrogen in serum of 5%CF group and 10%CF group decreased significantly（P<0.05）,and the triglyceride content in 15%CF group was also reduced（P<0.05）,while the blood glucose levels in 10%CF group and 15%CF group were higher than those in control group（P<0.05）.3、Effect of chicory fiber on intestinal health of rats（1）In terms of intestinal morphology,dietary supplementation with CF increases the villus height and villus height/crypt depth ratio of the small intestine,and reduces the crypt depth.In duodenum,compared with the control group,dietary supplementation with CF significantly reduced the depth of duodenal crypts（P<0.01,P<0.01 and P<0.05,respectively）and increased the V/C ratio（P<0.01）.In jejunum,the crypt depth was significantly reduced and V/C ratio was increased in 5%CF group（P<0.01）,The 15%CF markedly increased the villus height of jejunum（P<0.01）and ileum（P<0.05）.（2）In terms of jejunum and ileum barrier gene expression,different levels of CF could significantly increase the relative mRNA expression levels including ZO-1,claudin-1 in the jejunum and occludin in the ileum（P<0.01）;different levels of CF could significantly increase the relative mRNA expression levels of CAMP,β-defensel in the ileum（P<0.01）,and significantly increase the genes of CAMP and β-defense2 in the jejunum（P<0.05）;different levels of CF could significantly increase the relative expression abundance of mucin3,mucin4 in the ileum and mucin2,mucin3,mucin4 in the ileum（P<0.01）.（3）In terms of intestinal microorganisms,the addition of CF to the diet changed the cecum microbial flora structure and reduced microbial diversity;significantly increased the relative abundance of Bacteroides in the cecum（P<0.001）,and reduced the ratio of Firmicutes/Bacteroides（5%CF:P<0.05;10%CF:P<0.001;15%CF：P<0.01）and the relative abundance of Proteobacteria and Verrucococcum（10%CF Proteobacteria:P<0.05,15%CF Verrucococcum:P<0.05）.CF could enrich short-chain fatty acid-producing bacteria（e.g.,Anaerostipes and Lachnoclostridium）,while reducing the relative abudance of some bacteria related to intestinal inflammation（e.g.,Desulfouibrio and Sutterella）.（4）In terms of SCFAs content,the addition of CF to the diet also significantly increased the concentrations of butyric acid and total SCFAs in the cecum contents（P<0.001）,the concentrations of acetic acid increased in 5%CF and 10%CF（P<0.001）and propionic acid increased in 10%CF and 15%CF（P<0.001）.The relative mRNA expression of co-receptors GPR41 and GPR43 was also highly increased（P<0.01）.（5）In terms of spearman correlation analysis,indicated that the number born alive was positively correlated with Anaerostipes（P<0.05）,Subdoligranulum（P<0.001）and Lachnoclostridium（P=0.051）.The litter weight was positively correlated with Anaerostipes（P<0.05）,Ruminiclostridium₅（P<0.05）and Prevotellaceae_NK3B31_group（P<0.05）.In summary,CF can improve the reproductive performance and promote the intestinal health of pregnant rat,and the optimal adding level of CF is 10%.