Digestibility of starch and ingestive behavior of feedlot steers by effect of enzymatic complex doses in high-energy diets

ABSTRACT The objective was to evaluate the feed conversion, starch digestibility, ingestive behavior, diet leftover score and feces score of steers supplemented with doses of enzyme complex (0; 2.5; 5.0 and 7 .5g animal -1 day -1 ) fed with roughage-free diet composed of a mixture of 85% whole corn grain and 15% protein-mineral-vitamin mix, on a dry matter basis. A completely randomized block design was adopted, consisting of four treatments and four replicates. Thirty-two ½ Angus ½ Nellore crossbred steers at an average age of 12 months, with an average initial weight of 422kg, were kept in a feedlot for 77 days. Each gram of enzyme complex inclusion improved feed conversion in 0.1652%, decreased feces dry matter in 0,4648% and time of water intake in 0.0068 hours day -1 . The maximum starch digestibility was reached in the dose of 5,08g animal -1 day -1 . The gradual inclusion of enzyme complex promoted improvement in feed conversion, reduction in the dry matter of feces and redution in the time of water intake. The enzyme complex dose of 5.0g animal -1 day -1 increased the starch digestibility.