Effects Of Slow-release Compound Acidifiers On Gastrointestinal PH And Intestinal Morphology & Function In Weaning Piglets

The experiment was conducted to study the effects of the addition of encapsulated and non-encapsulated compound acidifiers in a diet based on corn-soybean meal-extruded soybean on gastrointestinal pH, growth performance, digestive organ development, villus height and crypt depth of jejunum, intestinal digestive enzymes activities, microbial population and intestinal mucosal secretory immunoglobulin A (SIgA) in weaning piglets. One hundred and twelve 28-day-old, crossbred piglets (Landrace×Large White), weighing an average of 7.00±0.10 kg, were randomly assigned to seven treatments with four replicates and four piglets (2 male and 2 female) per pen, according to single-factor design principle. The feeding trial lasted for 5 weeks after 3 days' pre-feeding. Experiment 1 studied on no addition of antibiotics in the weaning piglet diet, while experiment 2 studied on the addition of antibiotics.The results in experiment 1 showed as follows, as compared to no acidifiers, slow-release compound acidifiers increased the feed efficiency (P<0.01), and decreased the incidence of diarrhea. Slow-release compound acidifiers reduced the pH in stomach and small intestine (P<0.01) . In addition, slow-release compound acidifiers increased the ratio between villus height and crypt depth of jejunum (P<0.01) . In the early period, slow-release compound acidifiers increased the counts of lactobacillus in cecum and colon (P<0.05), while during the later weaning period, slow-release compound acidifiers decreased the counts of Escherichia coli (P<0.01) . It was also noted that there was an insignificant tendency of lower secretion of intestinal mucosal SIgA (P>0.05) . What's more, slow-release compound acidifiers could not only increase the relative weight of stomach (P<0.01) , but also stimulate the sucrase activity and lactase activity in trial group 2 (P<0.05) .The results in experiment 2 showed as follows, as compared to no acidifiers, slow-release compound acidifiers reduced the pH in stomach and small intestine (P<0.01) . In addition, slow-release compound acidifiers increased the ratio between villus height and crypt depth of jejunum (P<0.01), and stimulated the sucrase activity and lactase activity in the early weaning period (P<0.05) . During the later weaning period, slow-release compound acidifiers increased the counts of lactobacillus and decreased the counts of Escherichia coli in cecum and colon (P<0.01) . There was also an insignificant tendency of lower secretion of intestinal mucosal SIgA (P>0.05) . Slow-release compound acidifiers could increase not only the relative weight of stomach, but also the relative weight of small intestine in trial group 2(P<0.01) . When compared to non-encapsulated acidifiers, slow-release compound acidifiers not only improved the average daily gain and the feed efficiency (P<0.01) , but also reduced the incidence of diarrhea. Slow-release compound also reduced the pH in jejunum and ileum (P<0.01) . What's more, slow-release compound acidifiers increased the relative weight of stomach (P<0.01) , and increased the relative weight of small intestine (P<0.01 or P<0.05) . In addition, slow-release compound acidifiers increased the ratio between villus height and crypt depth of jejunum (P<0.01) , and stimulated the sucrase activity and lactase activity in the early weaning period (P<0.05) . During the later weaning period, slow-release compound acidifiers increased the counts of lactobacillus and decreased the counts of Escherichia coli in cecum and colon (P<0.01) .These results indicated that the slow-release compound acidifiers may be benefit for the development of intestinal tract and it may optimize the intestinal microflora and improve the intestinal morphology and function by reducing the gastrointestinal pH, so as to enhance the intestinal digestibility and adaptation after weaning. The combination of slow-release compound acidifiers and antibiotics in the weaning piglet diet could improve the growth performance and the morphology and function of digestive tract further in weaning piglets.