Effects Of Two Acidifiers On Growth Performance And Intestinal Health Of Weaned Piglets

In pig production,early weaning can easily lead to weaning stress,reduce growth performance of piglets and affect production efficiency.The use of antibiotics is one of the effective ways to solve the problem of weaning stress.China will ban the use of antibiotics in animal feed in 2020.As a green and safe additive with multiple physiological functions and no side effects of antibiotics,acidifier may play an important role in pig production.Single factor design was used to select 28-day old weaned piglets,which were randomly divided into 5 treatment groups with 6 replicates in each group and 6 pigs in each replicate.Group A was the control group,and group B was the antibiotic group(added30g/t of 50% virginiamycin in the basic diet).The basic diet was used in group C,but SCFA liquid acidifier was added in drinking water at a ratio of 1:1000.2kg/T compound acidifier was added to the basic diet on Group D.Group E added 2kg/T complex acidifier in the basic diet,and added SCFA liquid acidifier in drinking water at a ratio of 1:1000.The amount of each test additive was added in proportion to the test plan,and SCFA acidifier and compound acidifier were provided by Nutreco from the Netherlands.The experimental pigs were free to eat and drink,and were allowed to record and clean up the remaining feed each morning.Other procedures in accordance with the normal pig farm procedures.The weaning piglets started the experiment at the 28 th day of age,the pre-feeding period was 7days,the formal experimental period was 35 days,and the fasting samples were collected at the 49 th day of age.The results showed that :(1)compared with the control group,dietary addition of SCFA acidifier,compound acidifier and SCFA acidifier + compound acidifier increased the average daily weight gain(ADG)of weaned piglets aged 35-49 days,decreased the feed weight ratio(F/G)and diarrhea rate,but not significantly(P > 0.05).The average daily intake(ADFI)decreased.The growth performance of the compound group was better than that of the SCFA group and the compound acidifier group,but the difference was not significant(P > 0.05).(2)compared with the control group,piglets weaned between 50 and70 days old: dietary addition of SCFA acidifier significantly increased the level of ADG(P<0.05)and significantly reduced the diarrhea rate(P<0.05).ADFI showed an increasing trend and F/G showed a decreasing trend,but it was not significant(P<0.05).Dietarysupplementation with complex acidifiers significantly increased ADG levels(P<0.05)and significantly decreased F/G.ADFI increased and diarrhea decreased,but not significantly(P<0.05).Dietary addition of SCFA acidifier significantly increased ADG and ADFI levels(P<0.05),and significantly reduced F/G and diarrhea rates(P<0.05).Among them,the overall effect of SCFA acidifier on the improvement of growth performance is better than that of compound acidifier,and the combined use of the two is better.(3)compared with the control group,dietary addition of SCFA acidifier,compound acidifier or SCFA acidifier + compound acidifier all significantly increased lipase and total protease activities of weaned piglets(P<0.05),but had no significant effect on amylase activity(P>0.05).(4)compared with the control group,dietary addition of SCFA acidifier significantly increased the duodenal villus height and the duodenal V/C value(P<0.05),while the jejunal and ileum villus height and V/C value showed an increasing trend but was not significant(P>0.05).The duodenal crypt depth was significantly decreased(P<0.05),and the jejunal and ileum crypt depth was decreased but not significantly(P>0.05).The villus height and V/C values of duodenum,jejunum and ileum were increased and the crypto depth was decreased by adding complex acidifying agents to diets,but not significantly(P<0.05).The villus height and V/C values of duodenum,jejunum and ileum were increased and the crypto depth was decreased by adding SCFA acidifier and compound acidifier into diet.Among them,the duodenal recess depth,duodenal V/C value,jejunal villus height and V/C value reached the significant level(P<0.05),while the others were not significant(P>0.05).(5)compared with the control group,there was no significant difference in the composition and structure of intestinal microorganisms when adding SCFA acidifier,compound acidifier or SCFA acidifier + compound acidifier into the diet.The number and diversity of bacteria in the three experimental groups were higher than those in the control group,but did not reach the significant level(P>0.05).(6)compared with the control group,dietary addition of SCFA acidifier significantly increased the contents of acetic acid,propionic acid,isobutyric acid and total SCFA in the intestinal tract of weaned piglets(P<0.05),while the rest SCFA was not significant(P>0.05).The contents of butyric acid,valeric acid and total SCFA in the intestinal tract of weaned piglets were significantly increased by adding compound acidifier in diet(P<0.05),while the rest SCFA was not significantly increased(P>0.05).The content of acetic acid,propionic acid,isobutyric acid,isovaleric acid and total SCFA was significantly increased by adding SCFA acidifier and compound acidifier into diet(P<0.05),while the rest SCFA was not significant(P>0.05).There were significant differences in the total SCFA content among the three test groups(P<0.05),among which the SCFA acidifier group was higher than the compound acidifier group,and the compound group had the highest total SCFA content,which was about twice as much as the control group.To sum up,dietary addition of SCFA acidifier and compound acidifier can improve growth performance and intestinal health of weaned piglets to some extent.Moreover,there was a delay in the improvement of growth performance of weaned piglets with the two kinds of acidifiers,and it took about 2 weeks to fully reflect the effects of the two kinds of acidifiers.Among them,the effect of SCFA acidifier is better than that of compound acidifier,and the combination of the two will produce better interaction effect.