Abstract
Weaning is an unavoidable stressor for dairy and beef calves. Maternal bovine appeasing substance (MBAS) is a naturally secreted pheromone that induces an appeasing effect on nursing offspring. Our objective was to determine if a single topical dose of synthetic MBAS analog would lower cortisol concentrations, improve performance, and alter behavior outcomes of beef-dairy calves during weaning. Twenty-six individually housed male beef-dairy (Angus-Holstein cross) calves were blocked by weight (72 ± 6 kg) and randomized to either saline (CONT) or MBAS (MBAS; FerAppease, Fera D&B, College Station, TX). Calves received a single 10 mL dose of the designated treatment (5 mL on the poll, 5 mL on the muzzle) on day 0 prior to 3-d step-down weaning. Blood was collected on days 0, 1, 3, and 10. Calf starter intake and refusals were weighed and recorded daily. Body weights (BW) were collected every other day for 10 d following weaning. Average daily gain (ADG) and gain-to-feed (G:F) were calculated. Behavior was assessed using cameras, microphones, and accelerometers. Linear mixed models with effects of time, treatment and interaction were used to analyze cortisol, performance, and behavior variables with block and calf as random effects. Cortisol concentrations were significantly (P < 0.05) lower for CONT than MBAS. There were no treatment effects on BW or G:F between CONT and MBAS. Several treatment × time interactions (P < 0.05) were found for behaviors, with CONT having more lying bouts than MBAS on day 0. Additionally, CONT exhibited more nutritive oral behaviors (P = 0.01), defined as calf ingesting feed with their head over the feed bucket, post-treatment than MBAS. Vocalizations did not differ between treatments (P > 0.32) at any time during the trial. This research demonstrates that MBAS altered behavior during weaning, but it did not improve performance or blood cortisol compared to CONT.