Effects Of Dietary Energy And Protein Levels For Gestating Sows On Intestinal Development And Immune Function Of Offspring

Maternal nutrition during gestation plays an important role in the growth and development of offspring.Maternal nutritional deficiency usually lead to low birth weight neonates,which impared the development of intestine and immune function,especially in offspring which suffered the maternal energy or protein malnutrition.The development and function of small intestine is the key to optimal growth and health of animals and plays an important role in nutrient digestion and uptake,energy and nutrient expenditure and immunity.During the development of fetus and perinatal period,the small intestine is affected by maternal environment and nutrient intake.In this paper,two experiments was used to clarify the effects of dietary energy and protein levels during gestation on intestinal development and immune function of newborn and weaned piglets under LPS immune stress.Experiment 1:The aim of the study was to investigate the effects of maternal pregnancy intensity and protein levels on intestinal development and intestinal function in newborn piglets:In this study,A total of 72 LY(Landrace×Yorkshire)sows with weight and backfat similarity were randomly divided into four groups:NN group(T1),NH group(T2),LN group(T3)and LH group(T4).Basic diet nutrition needs to comply with NRC(2012).The results showed that:Sows fed with LN level during pregnancy reduced the birth weight,small intestine weight and the ratio of small intestine weight to SI length of newborn piglets(P<0.05),and increased the relative length of small intestine(P<0.05).At the same time,the content of GLP-2 in the plasma of newborn piglets was decreased by feeding the LN diet(P<0.05).Intestinal morphology:The villi height of jejunum in LN group was significantly lower than other groups(P<0.05).The ratio of villus height to crypt depth was significantly lower than the low energy high protein group(P<0.05).Intestinal digestive enzyme activity:Maternal feeding LN level diets improve the activity of lactase in newborn piglets(P<0.05),and decreased the sucrase and alkaline phosphatase activity(P<0.05).Intestinal immunity:The gene expression of pro-inflammatory cytokines IL-6 and TNF-a in the ileum of of newborn piglets was improved by feeding the T3 diet(P<0.05).The results suggest that the level of LN during pregnancy not only can reduce the birth weight of piglets,but also hinder the development of small intestine,and may damage its immune function..Experiment 2:Effects of sows energy and protein levels on immune response in weaned piglets challenged with LPS.After the experiment 1 was over,adjust the number of piglets in the sows,all sows fed the same diet during lactation until weaned(The lactation period is 28 days).From the four groups,12 healthy weaned piglets with weight equal to the weight of the nest were selected,divided into two groups.Six piglets were injected with LPS and the other six were injected with equal volume of saline.Piglets were sampled after 4 hours of injection.The results showed that the weaning weight of the piglets fed with LN diet was significantly lower than that of the other groups(P<0.05).The ratio of small intestine weight to small intestine length in +LPS LN group was significantly lower than that in NN group(P<0.05).The length of small intestinal was significantly lower than that of energy normal group(P<0.05).The weight of small intestine in +LPS LN group was significantly lower than that in high energy group(P<0.05),which was significantly lower than that in +LPS NN group(P<0.05).Intestinal morphology:the villi height of duodenum in the-LPS LN group was significantly higher than that in low energy high protein group,-LPS energy normal group(P<0.05).The crypt depth of jejunum in the LN group were significantly lower than-LPS NH group(P<0.05).The ratio of small intestine weight to small intestine length of Ileum in the +LPS LN group was significantly lower than NN group and-LPS NH group.Immune function:The maternal dietary energy level significantly affected the plasma IgM levels in piglets(P=0.010).The interaction between energy and protein significantly affected the level of IgA(P=0.019).LPS increased the concentration of TNF-a and IL-10 in piglet plasma.The expression of NF-KBmRNA in +LPS LN group was significantly higher than in-LPS low energy group(P<0.05).The expression of Claudin-1 gene in LN group was significantly lower than that in energy normal group(P<0.05).LPS increased the content of Escherichia coli in colonic chyme(P=0.009).The level of protein on maternal gestational significantly affected the concentration of butyric acid(P = 0.049),-LPS energy normal level(P<0.05),and the content of Escherichia coli in colonic chyme was increased by LPS(P<0.05).The concentration of butyric acid in colony chyme in the-LPS NH group was significantly higher than + LPS groups and-LPS LN group(P<0.05).The above results indicate that the maternal feeding of LN level can reduce the intestinal barrier function,increase the sensitivity to stress,and the addition of energy normal can enhance the development of the gut.The high protein level may improve the immune function of offspring.Conclusion:The present results demonstrate that both energy and protein in gestational diets affect birth weight and inteistinal development as well as immune function in newborn and weaned piglets.The LN diet significantly decreased birth weight and impaired intestinal development compared with the other groups.Increasing dietary protein levels could improve the intestinal development and immune function of weaned piglets with acute LPS challenges.