Effect of Feeding a Corn Hybrid Containing Alpha Amylase As Dry Rolled or High Moisture Corn on Finishing Performance and Carcass Characteristics

Abstract Text: A 173 d finishing trial was conducted to compare feeding a corn hybrid containing an alpha amylase enzyme (Syngenta Enhanced Feed Corn™; SYT-EFC) or a near isoline negative control (NEG) as dry rolled (DRC) or high moisture corn (HMC) on steer performance and carcass characteristics.  Three hundred eighty four calf-fed steers (310 ± 20 kg) were utilized in a randomized block design with 8 steers per pen and 6 replications per treatment. Dietary treatments were designed as a 2x2x2 factorial arrangement.  Factors included corn trait (SYT-EFC or NEG), by-product type [Sweet Bran (SB) or modified distillers grains plus solubles (MDGS)], and corn processing (DRC or HMC).  No 3-way interactions were observed (P ≥ 0.21) between corn trait, byproduct type, and corn processing for performance and carcass data.  However, steers fed SYT-EFC as DRC with MDGS had a 3.9% increase in G:F compared to NEG.  When fed as HMC with MDGS, G:F was improved by 2.1% for SYT-EFC over NEG. Feed efficiency was improved 1.5% for steers fed SYT-EFC as DRC with SB compared to NEG.  However, when processed as HMC, G:F decreased by 2.1% when steers consumed SYT-EFC compared to NEG with SB.  A corn processing x corn trait interaction was observed for final BW and ADG (P = 0.02 and P = 0.04, respectively).  Steers that consumed SYT-EFC as DRC had the greatest final BW and ADG while steers fed SYT-EFC as HMC had lower final BW and ADG.  A tendency for a corn processing x corn trait interaction was observed for HCW (P = 0.08), marbling score (P = 0.09), and 12^th rib fat thickness (P = 0.07).  Steers consuming SYT-EFC as DRC had increased HCW and marbling scores compared to NEG DRC whereas the opposite was true when fed as HMC.  Cattle consuming SYT-EFC as HMC had the greatest 12^th rib fat thickness with SYT-EFC as DRC had the lowest.  A tendency for a byproduct x corn trait interaction (P = 0.13) for G:F was observed.  Steers fed SYT-EFC with MDGS had a 3.0% increase in G:F compared to NEG.  Accounting for corn grain concentration in the diet, G:F increases to 4.5% for SYT-EFC over NEG corn. However, differences in G:F when fed with SB were reduced by less than 1%.  These data suggest that when processed as DRC, SYT-EFC improves G:F of feedlot steers, however mixed results were observed when fed with different byproducts.

Keywords: Alpha amylase, Corn processing, Finishing cattle