Feeding a brown midrib corn silage-based diet to growing beef steers improves growth performance and economic returns

A feedlot experiment was performed to determine growth performance, ruminal fermentation characteristics, and economic returns for growing beef steers when fed a brown midrib corn silage-based total mixed ration (BMRT) compared with a conventional corn silage-based total mixed ration (CCST). Twenty-four Angus crossbred steers (initial body weight = 258 +/- 23.2 kg) in individual pens were used in a completely randomized design (n = 12). Intake of dry matter was not different between the treatments. Steers fed the BMRT tended to have greater average daily gain (1.54 vs. 1.42 kg d(-1); P = 0.09) and gain-to-feed ratio (0.165 vs. 0.146; P = 0.07) compared with those fed the CCST. Feeding the BMRT increased total volatile fatty acid (VFA) concentration (P = 0.01) compared with the CCST, while it decreased molar proportion of acetate (P < 0.01), and increased propionate proportion (P = 0.01), resulting in decreased acetate-to-propionate ratio compared with the CCST (P < 0.01). Steers fed the BMRT increased feed margin (P = 0.05) and net return (P = 0.02) compared with those fed the CCST throughout the trial. Overall results of this study indicate that feeding the BMRT to growing beef steers enhanced ruminal fermentation and beneficially shifted VFA profiles, which contributed to improved growth and economic performance of steers.