EFFECTS OF DIFFERENT ENZYME PREPARATIONS ON GROWTH-RATE AND FEED-EFFICIENCY IN BROILERS FED ON MASH OR PELLETED BARLEY-CONTAINING DIETS

The efficacy of four different enzyme preparations containing both bet a-glucanase and arabinoxylanase activities was studied in two experime nts on chicks fed on barley-containing diets given as mash or as pelle ts. In Expt. 1, starter and finisher mash diets were used, containing 15% and 18% barley, respectively. The inclusion of ail enzymes resulte d in improvements in body weight gain as compared with the control gro up, the differences being significant in most cases. Feed efficiency w as also improved with all enzyme supplements. The improvements were gr eater in the starter period (1-21 days) than in the finisher period (2 1-42 days). In Expt. 2, pelleted diets of the same composition as in E xpt. 1 were used. Weight gains were significantly increased and feed e fficiency improved in all enzyme-treated groups. Similarly like in Exp t. 1, the effect of enzymes was more evident in the starter period tha n in the finisher period. There was no close relationship between beta -glucanase or xylanase activity as determined in vitro and the biologi cal efficacy of enzyme preparations.