Effects Of Yeast Culture Instead Of Antibiotics On Growth Performance And Intestinal Health Of Weaned Piglets

Yeast culture is rich in nutrients,which can improve the performance and immunity of livestock and poultry.It is a good substitute for antibiotics.In this experiment,yeast culture was added to the diets of weaned piglets to explore the effect of yeast culture instead of antibiotics on the growth performance,intestinal health and cecal microflora of weaned piglets,so as to provide theoretical support for the application of yeast culture instead of antibiotics in productionIn the experiment,180 weaned piglets of 28-day-old weaned with similar body weight were selected,and they were divided into three groups according to the principle of uniform weight.Each group had four replicates and 15 piglets each.The control group was fed a basic diet.The antibiotic group was supplemented with chlortetracycline 75g/t+guineamycin 50g/t+and virginiamycin 10g/t.Yeast culture group added 5kg/t yeast culture on the basis of basic diet,and the test period was 38 days.The results showed that the addition of yeast culture and antibiotics significantly increased the daily gain of weaned piglets(P<0.05),significantly reduced the feed to weight ratio and diarrhea rate of weaned piglets(P<0.05),but there was no significant difference in the daily intake between the three groups(P>0.05);The apparent digestibility of crude protein,crude fat and phosphorus in feed of weaned piglets was significantly increased by adding yeast culture and antibiotics(P<0.05);The addition of yeast culture and antibiotics significantly increased duodenal trypsin activity(P<0.05),but had no significant effect on amylase and lipase activity(P>0.05).Adding yeast culture significantly increased the height of duodenal villus and the ratio of ileal villus to crypt(P<0.05).There was a tendency to decrease the depth of jejunal crypt(P=0.051).Adding yeast culture and antibiotics had no significant effect on the depth of duodenal crypt.the height of jejunal villus.the height of ileal villus,the depth of crypt and the ratio of villus to crypt(P>0.05).The pH value of jejunal content was significantly reduced by adding yeast culture(P<0.05),but there was no significant effect on the pH value of jejunal content of weaned piglets(P>0.05);The content of immunoglobulin M in serum of weaned piglets was significantly increased by adding antibiotics and yeast culture(P<0.05),but there was no significant effect on the content of immunoglobulin G in serum by adding yeast culture and antibiotics(P>0.05).Adding yeast.culture significantly reduced the expression of TNF-α,TLR4 and IL-8 at mRNA level in jejunum mucosa of weaned piglets(P<0.05),but compared with the control group,adding yeast culture had no significant effect on the relative expression of inflammatory factors at mRNA level in spleen of weaned piglets(P>0.05).There was no significant effect of yeast culture and antibiotics on the relative expression of connexin in jejunum mucosa of weaned piglets(P>0.05).The dominant microflora among the three groups did not change at the plylum level.However,the abundance of spirochetes in yeast culture group was significantly lower than that in control group(P<0.05).Compared with the control group,yeast culture significantly reduced the abundance of Spirocheetaceae,Christensenellaceae,Campylobacter,Enterobacteriaceae(P<0.05),and significantly increased the abundance of Atophobiaceae and Pasteurellaceae.Compared with the non antibiotic group,the addition of antibiotics significantly increased the abundance of Streptococcaceae,Muribacuculaceae,Peptostreptococcaceae(P<0.05),significantly reduced the abundance of Campylobacteriaceae,Christensenellaceae and Enterobacteriaceae(P<0.05).The abundance of Christensenellaceae-R-7,Escherichia-Shigella and Treponema-2 in the control group was significantly higher than that in the yeast culture group and antibiotic group(P<0.05).The abundance of Vibrio butyricus in yeast culture group was lower than that in control group(P=0.056).The abundance of rare Micrococcus in yeast culture group was higher than that in control group(P=0.082).Addition of yeast culture increased the abundance of Prevotella-2(P=0.064),Prevotella-7(P=0.058),Prevotella-9(P=0.072),but there was no significant difference in the alpha diversity index among the three groups(P>0.05).To sum up:adding yeast culture significantly improved the production performance of weaned piglets,reduced the diarrhea rate of weaned piglets,improved the apparent digestibility and protease activity of weaned piglets,improved the morphological structure of the intestinal tract and the pH of the internal environment of weaned piglets,improved the serum immune level of weaned piglets,and improved the intestinal health of piglets.It reduced the relative abundance of harmful bacteria in the intestine of weaned piglets,improved the micro ecological environment of the intestine of weaned piglets,and achieved the feeding effect similar to that of antibiotics.