PSVI-19 Evaluating the addition of an alpha-amylase enzyme to two bulk-flake density weights of corn fed to beef finishing steers

Abstract An alpha-amylase enzyme has the potential to increase starch digestibility, thus improving feedlot cattle performance and efficiency. The objective of this experiment was to evaluate the addition of an alpha-amylase enzyme on two steam-flaked bulk densities and subsequent performance of finishing beef steers. Forty-eight crossbred steers (325 ± 19 kg), were used in a complete randomized block design with a 2 × 2 factorial treatment design. Factors were corn processing and enzyme addition. Dietary treatments were steam-flaked corn-based diets with two bulk-flake density weights of corn (0.32 kg/L vs. 0.39 kg/L). Experimental treatments were 1) 0.32 kg/L with no enzyme (32NE), 2) 0.39 kg/L with no enzyme (39NE), 3) 0.32 kg/L with enzyme (32E), and 4) 0.39 kg/L with enzyme (39E) on a DM basis. The enzyme was applied at 0.50 kg/T of steam-flaked corn (As-fed basis). Data were analyzed using a mixed model with fixed effects of flake weight, enzyme, and flake weight × enzyme interaction. Throughout the feeding period, starch availability for 0.32 kg/L and 0.39 kg/L corn averaged 60.7% and 42.2%, respectively. Steers receiving the alpha-amylase enzyme had no differences in BW (P ≥ 0.62), ADG (P ≥ 0.55), and DMI (P ≥ 0.56) compared to NE steers. Furthermore, carcass characteristics did not differ (P ≥ 0.26) between E and NE steers. Feeding an alpha-amylase enzyme to finishing cattle had no detrimental effects on performance or carcass characteristics. Overall, a more highly processed corn was observed to decrease dry matter intake and increase the potential for digestive upsets. This may limit the use of the alpha-amylase enzyme to a lesser processed corn.