Effect of lactulose supplementation on growth performance, intestinal histomorphology, cecal microbial population, and short-chain fatty acid composition of broiler chickens.

This study investigated the effects of dietary lactulose supplementation on broiler growth performance, intestinal histomorphology, cecal microflora, and cecal short-chain fatty acid (SCFA) concentrations. A total of 245 one-day-old male broiler chickens were randomly assigned to 5 different treatments, with 7 replicates including 7 birds each. The birds received the same basal diet based on corn--soybean meal, and lactulose was included in the diet at 0, 0.2, 0.4, 0.6, or 0.8% at the expense of corn and/or soybean meal. The body weight gain (linear, P=0.027) and feed conversion (linear, P=0.003) from 0 to 21 d showed significant improvement as dietary lactulose was increased from 0.2 to 0.8%. However, dietary lactulose did not affect broiler performance at the end of the experiment (42 d). Furthermore, intestinal measurements and the goblet cell count of broilers fed a lactulose-containing diet differed from those of birds fed a diet that did not contain lactulose. In addition, a significant quadratic response in the Lactobacillus count (P≤0.001) was observed at 42 d on increasing the level of lactulose. The cecal coliform bacterial population was not affected by the dietary treatments. Supplementation with lactulose significantly increased the concentrations of acetate, propionate, butyrate, and total SCFA measured on d 7 and d 42. In conclusion, inclusion of lactulose in the diet can enhance broiler performance and intestinal morphology by selectively stimulating intestinal microflora and increasing cecal SCFA concentrations.