Performance of broilers fed corn-soybean based diets with different levels of enzyme -- probiotic supplement

摘要

Three hundred all-male broiler chicks were randomly assigned to four treatment groups as follows: I (basal diet; control), II (basal diet + 0.15 percent enzyme-probiotic, EP supplement), III (basal diet + 0.30 percent EP supplement) and IV (basal diet + 0.45 percent EP supplement). The EP supplement is a multi-enzyme product containing microbial cellulase, amylase, maltase, protease and lipase, and 3.8 X 10 cfu/ml of beneficial species of Lactobacillus, Bifidobacterium, Aspergillus and Torulopsis.The apparent metabolizable energy (AME) of both starter and finisher diets improved with increasing levels of EP supplement, which was substantiated by reduced feed intake, higher weight gain and better feed efficiency in EP-supplemented compared with control birds. Since the EP supplement is a mixture, effects of the probiotic on broiler performance is difficult to distinguish from those due to exogenous enzymes. However, absence of mortality due to colisepticemia could be attributed to the probiotic component in EP-supplement-fed birds. Bird performance based on EP supplement inclusion level is as follows: 0.30 percent >0.45 percent >0.15 percent. It is possible to consider that at 0.45 percent level, enzyme activity was sufficient to significantly improve AME value of diets and increase nutrient availability but the probiotic component may have considerably increased the gut microfloral populations such that competition for available nutrients with that host animal was likewise increased. Results of the study lend support to the possibility that probiotic of adequate concentration could, in the absence of antibiotic growth promoters, complement the action of enzyme supplement in improving broiler performance.