Effects of supplemental vitamin E with different oil sources during preconditioning on gain and carcass parameters of finished beef calves

Sixty-four (224 ± 33 kg) Angus-cross calves were stratified by BW and sex and then randomly allotted to one of four 35-d preconditioning diets to evaluate the effect of supplemental vitamin E with or without dietary oil on BW gain and carcass characteristics. Diets were based on ad libitum grass hay (6.2% CP) and the following concentrates: corn and soybean meal only (CON), CON plus vitamin E (VITE), VITE plus 1.5% safflower oil (ELA), or VITE plus 1.5% flaxseed oil (ELNA). Vitamin E amounts were targeted for 150 IU/kg of total DMI (supplement plus hay). Following preconditioning, calves were shipped to a commercial feedlot and received a modified-live intranasal vaccine against infectious bovine rhinotracheitis and parainfluenza-3 following arrival to stimulate immune activity. Blood samples were obtained before transit and 30 d posttransit to quantify glucose and antibody titers. Data were evaluated as a randomized complete block design with sex as block using the preplanned contrasts of CON versus VITE, VITE versus oil (mean of ELA and ELNA), and ELA versus ELNA. No differences (P > 0.10) were observed for either preconditioning or feedlot ADG or for any carcass traits. Morbidity rates were less than 1% and consistent across treatments. No differences (P > 0.10) were observed for infectious bovine rhinotracheitis, parainfluenza-3, or IgM antibody titer concentrations across treatments. Preconditioning diets containing 150 IU of vitamin E/kg of DMI, regardless of oil, showed limited to no change in performance, immune, or carcass characteristics of weaned beef calves.