Impacts of Maternal Bovine Appeasing Substance Administered at Weaning on Behavioral and Physiological Adaptation of Beef Heifers to the Feedlot

The effects of administering 10 mL of maternal bovine appeasing substance (mBAS) or water (control) at weaning (day 0) before transport on feedlot adaptation and efficiency were evaluated in twenty-two Angus-influenced heifers (n = 11/treatment) over 28 days. Growth (BW, ADG), salivary cortisol, blood for complete blood cell count, rectal temperature, chute score and exit speed were collected on days 0, 14 and 27. Intake, feeding duration, frequency and rate, as well as activity and rumination were monitored daily using automated systems. Treated heifers spent less time eating (P < 0.001) on weeks 1 and 2, with greater feeding rate and activity (P < 0.05) in week 1, followed by reduced activity (P < 0.05) in weeks 2, 3 and 4. Rumination was longer (P < 0.05) in weeks 3 and 4, coinciding with greater (P < 0.05) final BW, ADG0–27, ADG14–27, and G:F0–27, G:F14–27. Lymphocyte and hematocrit were lower (P = 0.01) on days 14 and 27, respectively, and platelet tended to be greater (P = 0.07) than CT for the entire period. Treated heifers achieved greater profit margins (P < 0.05) than CT. Overall, mBAS enhanced feedlot adaptability post-weaning, improving production efficiency and profitability.