Effects Of Heat-treated Colostrum And Mannan Oligosaccharide Supplementation On Passive Immunity,intestinal Development And Microbial Composition Of Newborn Goats

The effects of heat-treated colostrum and mannan oligosaccharide supplementation on passive immunity,intestinal development and microbial composition of newborn goats were studied.Twenty-eight healthy newborn Xiangdong black goats with the birth weight of 2.35 ±0.55 kg were randomly assigned to four dietary treatments with seven goats in each treatment.The dietary treatments were as follows: colostrum(C),colostrum with mannan oligosaccharide(CM),heat-treated colostrum(HC)and heat-treated colostrum + mannan oligosaccharide(HCM)respectively for the first time,and then were fed milk replacer.Colostrum and milk replacer were fed at 5% of goats’ body weight,and mannan oligosaccharide was added at 0.02% of goats’ body weight.Experiment 1: the effects of feeding heat-treated colostrum and mannan oligosaccharide on the changes of plasma immunoglobulin G(IgG)and intestinal permeability of goats during 0-168 hrs.Experiment 2: the effects of heat-treated colostrum and mannan oligosaccharide supplementation on jejunal development and transcriptome analysis.Experiment 3: effects of heat-treated colostrum and mannan oligosaccharide on microbial diversity of jejunum in goats.The main results are as follows:1.The effects of heat-treated colostrum and mannan oligosaccharide supplementation on plasma IgG 0-168 hrs and intestinal permeability of goats.The plasma IgG concentration of newborn goats in each group increased with time,reached the peak of 15.11mg/ml at 12 hrs,and then stabilized.Heat treatment of colostrum could significantly increase the plasma IgG concentration at 6,12,24,96,144 and 168hrs(P < 0.05);Mannan oligosaccharide could significantly reduce the plasma IgG concentration at 3 and 6 hrs.(P < 0.05);The interaction between them was significant at 72 and 96hrs(P < 0.05).Heat treatment of colostrum and adding mannan oligosaccharide had no effect on the intestinal permeability of newborn goats.2.The effect of heat-treated colostrum and mannan oligosaccharide on the development of jejunum in goatsHeat-treated colostrum and mannan oligosaccharide supplementation had no significant effect on the length of jejunal villi,crypt depth and their ratio(P > 0.05),but the interaction between them was not significant(P > 0.05).Jejunal transcriptome analysis showed that feeding heat-treated colostrum and mannan oligosaccharide supplementation had little effect on the number of differentially expressed genes.However,the differentially expressed genes of newborn goats were mainly enriched in tight junction,endocytosis,adhesion junction,actin cytoskeleton regulation,homologous recombination,MAPK signaling pathway,phagosome,cell adhesion molecule,Erb B signaling pathway,Chemokine signaling pathway and NFκB and other signaling pathways.Heat treatment of colostrum significantly increased the expression of tight junction protein Claudin-1,while mannan oligosaccharide significantly increased the expression of Claudin-2 and Claudin-7 genes(P < 0.05),and decreased the expression of occludin gene(P < 0.05).There was significant interaction between them on Claudin-1,Claudin-7,and Occludin(P < 0.05).3.Effects of heat treatment of colostrum and inclusion of mannan oligosaccharide on microbial diversity in jejunum attachment of goats16S rDNA sequencing showed that heat treatment of colostrum and mannan oligosaccharide addition had no significant effect on OTU,Chao1,Shannon,Simpson and ACE index(P > 0.05).Firmicutes and Proteobacteria were the two most dominant phyla in the jejunum of goats.The sum of Firmicutes and Proteobacteria accounted for94.45%,87.85%,99.25% and 99.44% of the total bacteria in the four groups,respectively,but had no significant effect on jejunum(P > 0.05).Lactobacillus,Sarcina＿1,and Burkholderia caballeronia paraburkholderia＿1 were the dominant genera in the jejunum.There was no significant difference in the genus of bacteria among the groups,but there was a big difference among goats in the group.In conclusion,feeding heat-treated colostrum after birth can increase the plasma IgG concentration of newborn goats,but mannan oligosaccharide supplementation can reduce the plasma IgG concentration of newborn goats and prolong the time required for IgG to reach the maximum concentration.The present experiments showed that heat-treated colostrum and mannan oligosaccharide supplementation had no effect on the intestinal permeability of newborn goats.Nevertheless,transcriptome analysis showed that feeding heat-treated colostrum and mannan oligosaccharide could affect the expression of permeability-related genes,suggests that prolonged feeding could affect the barrier function of goats.Heat-treated colostrum and mannan oligosaccharide supplementation had little effect on the abundance and diversity of the jejunal microbial community of newborn goats,but there were significant differences among goats.