Effects Of Compound Acidifier Replacing Antibiotics And Zinc Oxide On Growth Performance And Intestinal Function Of Weaned Piglets

In order to study the effects of compound acidifier(lactic acid,fumaric acid,citric acid,sorbic acid,malic acid,etc.)on growth performance and intestinal function of weaned piglets,360 healthy weaned piglets weighing 6.03±0.04 kg at the age of 30 days old were randomly divided into six treatment groups,each group had 6 replicates.Each replicate was 10 pigs.According to the weight and sex of each pig,appropriate adjustments were made to ensure that there was no difference in the initial weight of each treatment group.The control group was fed with antibiotics and 0.2%zinc oxide.The group 1 was fed with antibiotics and 0.2%compound acidifier.The group 2 was fed with 0.2%compound acidifier.The group 3 was fed with 0.4%compound acidifier.The group 4 was fed with 0.2%compound acidifier and crude protein reduced by 1.5%.The group 5 was fed with 0.4%compound acidifier.Chemicals and crude protein reduced feed by 3%.The whole experiment was divided into two stages.The first stage was self-weaning piglets aged 21-36 days(14 days),the second stage was weaning piglets aged 37-50 days(14 days)and the experimental period was 28 days.The feeding intake and diarrhea status of weaned piglets were observed and recorded every day during the whole experiment.At the end of each stage,three piglets were randomly selected from each treatment group at 36 days of age,and then slaughtered and sampled.The blood,intestinal contents and jejunum tissues of piglets were collected for later experiment.The pH value of some gastrointestinal contents,the activity of digestive enzymes in gastrointestinal tract,some biochemical indexes in serum.jejunal tissue structure,jejunal immune cells and intestinal microorganisms were measured.To explore whether compound acidifier can replace antibiotics and zinc oxide to improve growth performance and intestinal health of weaned piglets,and to provide theoretical basis for the application of compound Acidifier in production.The results are as follows:1.The effect of compound acidifier replacing antibiotics and zinc oxide on growth performance and diarrhea rate of weaned piglets:At 21-35 days of age,the weight gain of weaned piglets in group 1 was the highest and the feed weight ratio was the lowest,which indicated that the growth performance of piglets fed diets supplemented with antibiotics and 0.2%compound acidifier was the best,and Acidifier had a positive effect on growth performance;control group and experimental group 2,experimental group 1.There was no significant difference in weight gain,feed intake and weight ratio among the three groups(P>0.05),indicating that there was no significant difference in growth performance of piglets fed diets supplemented with antibiotics,zinc oxide and 0.2%and 0.4%compound acidifiers.2.The effect of compound acidifier replacing antibiotics and zinc oxide on digestive and absorptive capacity of weaned piglets:The pH value of gastric contents of weaned piglets in experiment 1,2 and 3 groups was not significantly different from that of control group,but decreased to a certain extent,indicating that the addition of compound Acidifier in diet could stimulate the secretion of gastric acid to a certain extent.The contents of pepsinase in the duodenum,jejunum and ileum of weaned piglets in group 1 and group 3 were significantly higher than those of control group(P<0.05).The contents of chymotrypsin in duodenum,jejunum and ileum of weaned piglets in group 1 were significantly higher than those of control group(P<0.05).The length of villi in group 3 was significantly higher than that of control group(P<0.05).Group B(P<0.05).The results showed that the digestive and absorptive capacity of gastrointestinal tract of piglets was improved by adding antibiotics and compound Acidifier in diet and 0.4%compound acidifier compared with adding antibiotics and zinc oxide.3.The effect of compound acidifier replacing antibiotics and zinc oxide on serum biochemical indexes of weanling piglets:Compared with the control group,the contents of alanine aminotransferase,glutamic oxalase and alkaline phosphatase in serum of weanling piglets in test group 1,test group 2 and test group 3 all decreased,indicating that acidifier had protective effect on kidney and reduced liver injury of weanling piglets.There was no difference in the content of lactate dehydrogenase in the serum of piglets fed with acidifier diet,but the content of lactate dehydrogenase in serum of piglets fed with acidifier diet was lower than that of piglets fed with antibiotics and zinc oxide at the same time,which indicated that the damage of liver caused by metabolic Acidifier in piglets tended to be weaker than that caused by metabolic antibiotics.4.Effect of compound acidifier on intestinal microorganisms of weaned piglets:The number of Lactobacillus in cecum segment of weaned piglets in test 1 and 2 groups was the largest,significantly higher than that of control group and test 5 groups(P<0.05),and the number of Lactobacillus in colon segment of weaned piglets in test 1 group was the largest,and significantly higher than that of other groups(P<0.05).Compared with the control group,adding acidifier increased the number of Lactobacillus in colon and cecum,but decreased slightly due to the decrease of crude protein.Adding 0.2%compound Acidifier in diet also increased the number of bifidobacteria in jejunum and colon.The number of Enterococcus in piglets fed with antibiotics and 0.2%compound Acidifier in diet was higher than that in piglets fed with antibiotics and 0.2%compound acidifier.Low,indicating that the compound acidifier has a positive effect on the number of Lactobacillus,Bifidobacterium and other beneficial bacteria in the intestinal tract of piglets.