Effects Of Adding Fermented Alfalfa Meal To Diets On Growth Performance And Intestinal Microbe Of Weanling Piglets

This experiment added alfalfa meal and fermented alfalfa meal to the diet of 21day-old weaned piglets to explore its effects on growth performance,antioxidant capacity,intestinal development and post-intestinal microflora of early weaned piglets.A total of 120 piglets(DurocxLandracexLarge White,aged 21 days)with body weight of about 7 kg were randomly allotted to 4 treatments:control group(CG),alfalfa meal group(AG),2.5%fermented alfalfa meal group(2.5%FG),and 7.5%fermented alfalfa meal group(7.5%FG)。Each treatment included 3 replicated pens,each of which was 10 piglets.The pre-trial period was one week.The trial began at 28 days old and ended at 54 days old for a total of 27 days.Exp.1:At the end of the experiment,one piglet was randomly selected from each replicate to record its body weight before slaughter.The growth performance of piglets was recorded and the antioxidant indexes in serum and tissues were detected.The results showed that:①There was no significant effect on the average daily gain and F/G of the piglets in each treatment group,but the 2.5%FG feed-to-weight ratio was the lowest.②The heart index of AG was significantly higher than the other groups(P<0.05),and 2.5%FG promoted the lung and liver development of piglets.③Adding fiber to the diet increased the activity of CAT and GSH-PX in serum and decreased the content of MDA.And AG and 2.5%FG significantly increased the activity of CAT(P<0.05).In the liver,AG and 2.5%FG significantly reduced MDA content compared to CG(P<0.05),but if the addition ratio reached 7.5%,the MDA content increased and exceeded the amount of CG.In the kidney,the addition of alfalfa meal significantly increased T-AOC,CAT,and SOD activities(P<0.05).Compared with CG,the addition of fermented alfalfa meal can increase CAT activity,but the difference is not significant,and the CAT activity decreases as the amount of addition increases.In the spleen,AG and 2.5%FG significantly increased the activity of SOD(P<0.05).Exp.2:At the end of the experiment,one piglet was randomly selected from each replicate to record its body weight before slaughter,and the intestinal length,weight,pH of gastrointestinal contents,digestive enzyme activity and intestinal morphology were detected.The results showed that:①The length and weight of the 2.5%FG small intestine increased,and the weight gain was significantly higher than the other groups(P<0.05).The length and weight of the large intestine increased slightly(P>0.05).②Compared with CG,the addition of 2.5%fermented alfalfa meal reduced the pH of the stomach,duodenum,jejunum and colon contents(P>0.05).③Adding fiber to the diet,decreased amylase activity,increased lipase activity and trypsin activity in jejunum and ileum,but its activity was different in different parts of digestive tract,most of which was the highest in 2.5%FG.④The addition of 2.5%fermented alfalfa meal significantly increased the villus height of the duodenum and decreased the depth of the crypt(P<0.05),but when the addition amount was 7.5%,the duodenal villus height was significantly lower than the other Groups(P<0.05),but their crypt depth was also significantly lower than CG(P<0.05).VH:CD was highest with the addition of 2.5%FG and significantly higher than CG(P<0.05).In the ileum,both AG and 2.5%FG significantly increased their villus height(P<0.05).There is no significant impact on the crypt depth.VH:CD was the highest with 2.5%FG,and the difference was significant compared with CG and 7.5%FG(P<0.05),and the difference was not significant compared with AG.Exp.3:To explore the effect of adding fiber to diet on the microbial flora of cecum and colon in piglets by 16s rDNA sequencing.Results showed that:①The addition of fiber to the diet significantly increased the abundance and diversity of microorganisms in cecal and colonic mucosal samples.②2.5%FG significantly increased the relative abundance of unclassified_f_Lachnospiraceae,Ruminococcaceae_UCG-005,Faecalibacterium,Mitsuokella and Bacteroidales_S24-7_group,reducing the relative abundance of Helicobacter and Streptococcus.In summary,the addition of a certain amount of fiber in the diet of early weaned pigs has no adverse effect on its growth,and has a certain promoting effect on intestinal development,promoting the digestion and absorption of nutrients.At the same time,the microbial diversity of the hindgut is increased,the relative abundance of the beneficial genus is increased,the growth of the harmful genus is inhibited,and the health of the intestinal tract is maintained.Overall,the addition of 2.5%fermented alfalfa meal to the diet was the best.