| Intrauterine growth retardation(IUGR)refers to the slow growth and development of fetus and its organs in the uterus.IUGR can increase the incidence rate and mortality of the body during the new generation,and at the same time,it will have a negative effect on the growth and development of the body and the health condition.In modern large-scale breeding production,improving the litter rate of sows is also accompanied by the increase in the number of IUGR piglets,which seriously affect the growth and development of piglets,increase the mortality of piglets,and cause great losses to pig production.Therefore,it is very important to find effective nutritional regulation methods to improve the growth performance and health status of IUGR piglets.Impaired intestinal barrier function is one of the typical characteristics of IUGR piglets.Alginate oligosaccharide(AOS)possesses biological functions such as anti-inflammatory,antioxidant and regulating flora,and has the potential effect of improving intestinal barrier function.The purpose of this study was to explore the changes of intestinal barrier function and microflora of IUGR piglets and the regulation of AOS through animal feeding experiments,so as to provide a theoretical basis for the nutritional regulation strategy of IUGR and the application of AOS.Thirty-six normal birth weight(NBW)weaned piglets and 72 IUGR piglets of 28 days old were selected for the experiment.They were divided into three treatments: normal birth weight group(NBW piglets,fed with basic diet),intrauterine growth retardation group(IUGR piglets,fed with basic diet)and AOS group(IUGR piglets,fed with basic diet + 500mg/kg AOS).There were 6 replicates in each group and 6 piglets in each replicate.The test period was 28 days.The results showed that:(1)The average daily gain and average daily feed intake of IUGR group were significantly lower than NBW group(P<0.05);dietary supplementation of AOS had no significant effect on the average daily gain,average daily feed intake and feed gain ratio of IUGR piglets;(2)AOS decreased significantly the content of LDL in serum of IUGR piglets(P<0.05);(3)AOS increased significantly the total antioxidant capacity(T-AOC),total superoxide dismutase(T-SOD)and catalase(CAT)activities in serum of IUGR piglets(P<0.05);(4)Serum levels of interleukin(IL)-6 and tumor necrosis factor-α(TNF-α)in IUGR piglets were significantly higher than that in NBW piglets(P<0.05);and AOS decreased significantly the levels of IL-6 and TNF-α(P<0.05);(5)AOS increased significantly the content of immunoglobulin M(Ig M)in serum of IUGR piglets(P<0.05);(6)The m RNA expressions of intestinal tight junction protein ZO-1 and Occludin in IUGR piglets were significantly lower than that in NBW piglets,while AOS significantly increased the m RNA expressions of ZO-1,Claudin-1 and Occludin in IUGR piglets(P<0.05);(7)The ileal villus height of IUGR piglets was significantly lower than that of NBW piglets(P<0.05),while AOS significantly increased the ileal and jejunal villus height of IUGR piglets(P<0.05);(8)The analysis of intestinal flora based on 16 S r DNA sequencing showed that the relative abundance of Butyricoccus,Catenisphaera,Catenibacterium and Family＿XIII＿UCG＿001 was decreased significantly in IUGR group as compared with NBW piglets(P<0.05),and further correlation analysis showed that Catenisphaera and Catenibacterium were significantly positively correlated with the level of inflammatory factor TNF-α(P<0.05),while Catenisphaera was negatively correlated with the m RNA expression of tight junction protein Claudin-1(P<0.05).In conclusion,as compared with NBW weaned piglets,IUGR piglets showed the lower growth performance,higher levels of inflammatory factors,lower m RNA expression of intestinal tight junction proteins,and different structure of intestinal microbiota;dietary supplementation of AOS can improve the antioxidant capacity of IUGR piglets,reduce serum levels of inflammatory factors,increase the level of immunoglobulin Ig M,alleviate the intestinal mucosal injury of IUGR piglets,promote the expression of intestinal tight junction protein m RNA and increase the height of intestinal villi. |
