复合益生菌对育肥猪生长性能、养分表观消化率及肠屏障基因表达的影响OA

This study was conducted to investigate the effects of different supplemental levels of compound probiotics(CPs,a solid powder composed of Bacillus subtilis,Clostridium butyricum and Saccharomyces cerevisiae at a ratio of 2:1:1,with a total viable count≥1.0×1010 CFU/g)on growth performance,nutrient apparent digestibility and intestinal barrier gene expression of fattening pigs,and to determine the optimal addition amount in the diet of fattening pigs.Pigs with an initial body weight of(62.15±2.34)kg were randomly divided into five groups with six replicates per group and eight pigs per replicate.CK was fed a basal diet(corn-soybean meal type),and the four experimental groups(CPs1,CPs2,CPs3 and CPs4)were supplemented with 0.01％,0.02％,0.04％and 0.08％of CPs solid powder mixed into the basal diet,respectively.The results were as follows:(1)No significant differences were observed in final body weight(FW),average daily gain(ADG),average daily feed intake(ADFI)or feed-to-gain ratio(F/G)between the CPs1 group and the CK group(P>0.05).The FW in the CPs2,CPs3 and CPs4 groups was increased by 4.68％,9.24％and 9.74％(P<0.05),ADG was increased by 8.36％,19.59％and 20.16％(P<0.05),and F/G was decreased by 6.54％,15.03％and 15.36％(P<0.05),respectively.The FW,ADG and F/G of CPs3 were significantly better than those of CPs2(P<0.05),while no significant differences were observed between the CPs4 and CPs3(P>0.05).(2)The total tract apparent digestibility in CPs2,CPs3 and CPs4 were significantly higher than those in CK(P<0.05),with the CPs3 group showing the greatest improvements(increased by 6.32％,9.15％,12.28％and 20.01％,respectively).No significant differences were observed in all digestibility indices between CPs4 and CPs3(P>0.05),nor between the CPs1 and CK(P>0.05).(3)The relative mRNA expression levels of Claudin-1,Occludin,ZO-1 and MUC2 in the jejunum and ileum of the CPs2,CPs3 and CPs4 were significantly higher than those in CK(P<0.05),with CPs3 showing the greatest improvements in the jejunum(increased by 84.00％,86.00％,96.00％and 92.00％,respectively).The expression levels of all genes in both jejunum and ileum of CPs3 were significantly higher than those of CPs2(P<0.05),while no significant differences were observed between the CPs4 and CPs3(P>0.05).In conclusion,under the conditions of this study,the optimal addition amount of compound probiotics in the diet of fattening pigs is 0.02％to 0.08％,with the 0.04％addition showing the best effect.