Effect Of Sodium Butyrate And Niacin On Growth Performance,Intestinal Energy Metabolism And Microbial Flora In Weaned Piglets

Piglets suffer from severe diarrhea and growth retardation due to lack of intestinal energy and metabolic disorder of microbiota after weaning.Butyric acid is the main energy supply of colon and nicotinic acid is an important precursor of nicotinamide adenine dinucleotide（NAD）.As a important energy metabolite in the intestine of piglets,butyric acid and nicotinic acid can improve the microbial communities,regulate energy metabolism homeostasis,and then mediate various physiological processes in the intestine.Our study aimed to explore the effects of butyric acid and nicotinic acid on growth performance,energy metabolism,microbiota and metabolites of weaned piglets.The results are as follows:The effects of different proportions of sodium butyrate and niacin on growth,diarrhea index,serum biochemistry and immunoglobulins of weaned piglets.Seventy-two weaned piglets were randomly assigned to 1 of 6 treatments（12 pigs/treatment）:the control（CT）group was administered a basal diet.The experimental groups（BN1,BN2,BN4,BN8,and BN16）were administered a basal diet supplemented with 2000 mg/kg sodium butyrate and 20 mg/kg,40mg/kg,80 mg/kg,160 mg/kg or 320 mg/kg niacin（100:1,100:2,100:4,100:8and 100:16）.Feed and water were provided ad libitum during the entire experimental period.After 14 days treatment,the samples were collected.The results showed that sodium butyrate and niacin can promote the growth of piglets.Feed conversion rate（FCR）was reduced 9.9%and average daily gain（ADG）was increased 19.45%in BN2 group（P<0.05）.Additionally,the addition of sodium butyrate and niacin had a significant effect on the Ig M and blood glucose（P<0.05）,but had no significant effect on other serum biochemistry and immunoglobulins.2.The effects of different proportions of sodium butyrate and niacin on intestinal morphology,energy metabolism and macrophage typing in piglets.The results showed that there was no effect of sodium butyrate and niacin for the intestinal morphology.The addition of 2000 mg/kg sodium butyrate and40 mg/kg niacin to feed increased the content of NADH and NAD,reduced the ratio of NADH and NAD,promoted glycolysis and tricarboxylic acid cycle,and then induced M1 type macrophages into M2 type.However,the higher supplemention of sodium butyrate and niacin reduced the content of NADH and NAD,increased the ratio of NADH and NAD,inhibited glycolysis and tricarboxylic acid cycle,and then reduced the concentration of ATP without affecting the typing of macrophages.3.The effects of different proportions of sodium butyrate and niacin on intestinal microflora and metabolites in piglets.The results showed that:1)The addition of sodium butyrate and niacin to feed affected the alpha diversity of fecal bacteria composition among the groups.At the phylum level,the ratio of Firmicutes and Bacteroidetes increased first and then decreased with the increase of nicotinic acid.At the family and genus levels,the relative abundance of Lactobacillus increased with the addition of butyric acid nicotinic acid.In addition,the concentrations of nicotinamide and vitamin B₁₂were decreased and the concentrations of niacin,vitamin B₁,vitamin B₂and vitamin B₆were increased in feces.2)The addition of sodium butyrate and niacin to feed increased the concentration of acetic acid,butyric acid and propionic acid,and decreased the concentration of caproic acid.As 2000 mg/kg sodium butyrate and 40 mg/kg niacin were supplemented,the beneficial metabolites of colonic contents such as amino acids,butyric acid and vitamin B were more enriched than those in the high supplemention group.KEGG analysis showed significant enrichment of important pathways such as vitamin and butyric acid metabolism.In conclusion,the addition of 2000 mg/kg sodium butyrate and 40 mg/kg niacin to feed was the best proportion,which can improve production performance,reduce diarrhea index,promote intestinal energy metabolism,and strongly associate with macrophages typing,microbiota and metabolites.Sodium butyrate and niacin can be used as an energy supplemention in animal husbandry production.