Feeding two single strain probiotic bacteria and wheat bran failed to modify the production traits but altered some gut characteristics in broiler chickens

摘要

The effects of a single strain lactic acid producing bacteria (LAB) (Lactobacillus farciminis 5x109 CFU/kg) and a single strain butyric acid producing bacteria (BAB) (Clostridium butyricum 2.5x109 CFU/kg) with or without wheat bran supplementation (WB), were investigated on the production traits and on several gut characteristics of broiler chickens. In total, 576 male Ross 308 day-old chickens were divided into 24 floor pens and fed a corn-soybean based control diet (C) and five other probiotic or wheat bran supplemented diets (LAB, BAB, LAB+WB, BAB+WB, C+WB) in 4 replicates. The wheat bran content of the starter, grower and finisher diets were 3, 6 and 6%, respectively. During the 37 day long fattening period, growth rate, feed intake were recorded and feed conversion was calculated. At the end of the trial, 8 chickens per treatment were slaughtered and the following parameters investigated: trypsin, lipase and amylase activity of the jejunal chyme, ileal histomorphology and Lactobacillus load. None of the treatments resulted significant differences in the production traits (P0.1). BAB supplementation tended to decrease digestive enzyme activity. Feeding WB in all combination increased crypt depth (P=0.002), ileal muscle layer thickness (P=0.001) and decreased the villi: crypt ratio (P=0.037) in the ileum.