Effects of backgrounding nutrition and ratio of high-moisture to dry-rolled corn in finishing cattle diets on feedlot and carcass performance, and beef quality and fatty acid profile

Abstract

Two experiments were conducted in 2019 and 2020 at the Beef Research and Education Center feedlot near Rosemount, MN. Experiment one evaluated the effects of intake management, ad-libitum (AD-LIB) or restricted (REST), and dietary energy concentration, high (HI) or moderate (MOD), fed to steers (n = 139) during a 49-d backgrounding period in a 2 × 2 factorial design and finished on a common-finishing diet. Dietary treatments were 1) 1.43 NEg Mcal/kg ad-libitum (HI AD-LIB); 2) 1.43 NEg Mcal/kg fed to gain 1.13 kg/day (HI REST); 3) 1.31 NEg Mcal/kg ad-libitum (MOD AD-LIB); 4) 1.31 NEg Mcal/kg fed to gain 1.13 kg/day (MOD REST). Steers fed REST treatments exhibited reduced DMI in the backgrounding and finishing periods, and overall (P < 0.0001). Daily gain was reduced during the backgrounding phase and overall (P < 0.0001), but similar during the finishing phase. Carcass traits were poorer for cattle on REST treatments (P ≤ 0.04). There were no effects of intake management on live performance in the backgrounding or finishing periods or overall (P ≥ 0.15). Quality grade was improved for steers fed HI treatments (P = 0.04), but there were no other impacts on carcass characteristics (P ≥ 0.44). There were interactions for BF (P = 0.04) and HCW (P = 0.06). In experiment two incremental increases in the ratio (HMC-RAT) of high-moisture (HMC) to dry-rolled corn (DRC) were fed to steers (n = 115) during the finishing phase to investigate the effects of HMC-RAT on feedlot performance and carcass characteristics. Dietary treatments consisted of 1) 20:80 HMC:DRC; 2) 40:60 HMC:DRC; 3) 60:40 HMC:DRC; 4) 80:20 HMC:DRC with similar concentrations of corn silage, dried distiller grains with solubles, and supplement. Ratio of HMC:DRC did not impact feedlot performance. Yield grade was greatest for steers fed a 40:60, intermediate for 20:80, and least for 60:40 and 80:20 HMC:DRC, respectively (P = 0.04). Other carcass traits were similar across dietary treatments. Feeding AD-LIB during the backgrounding period improved live performance and carcass characteristics. Ratio of HMC:DRC did not exhibit effects on finishing performance or a majority of carcass traits. Key Words: cattle, backgrounding, finishing, feedlot, programmed gain, intake management, high-moisture corn, dry-rolled corn