Abstract Weaning is widely recognized as one of the most stressful management practices in beef production, as calves are abruptly separated from the dam and must simultaneously adapt to changes in nutrition, environment, and social structure. This process elicits behavioral and performance indicators of stress, including vocalizations, pacing, reduced feed intake, and lower weight gain. Traditional management strategies, such as fenceline separation, the use of nose-flaps to prevent nursing, or maintaining calves in familiar environments, have been investigated as methods to alleviate this stress. Recent research has shifted toward other approaches that target the biological mechanisms underlying stress responses. One approach involves the use of maternal bovine appeasing substances (mBAS), synthetic analogs of pheromones naturally produced by lactating cows that are thought to provide a calming effect on calves during periods of stress. This trial aimed to evaluate the effectiveness of mBAS in reducing stress during calf weaning. Data on calf weights and behavior were collected over 2 separate weaning periods. Period 1 included 50 Angus-influenced calves (25 heifers and 25 steers) averaging 190.8 ± 28.18 kg of BW. Period 2 included 58 Angus-influenced calves (34 heifers and 22 steers) averaging 215.7 ± 31.45 kg of BW. Both groups of calves were abruptly weaned, weighed, vaccinated against Clostridium and respiratory pathogens, dewormed, and allocated to one of two treatments balancing for gender and BW. Calves were administered either a 10 mL of the mBAS Ferappease (mBAS; n = 28) or 10 mL of mineral oil (CON; n = 28) applied topically to the nuchal skin and above the muzzle. Calves were immediately moved to fescue-based pasture and observed for 1-hour for behavioral stress including vocalizations, pacing, lying, and feeding. Structured behavioral observations were collected on d 0, 7, and 14. Body weights were collected on d 0 and 14. Vocalization from calves in period 2 were lower (P 0.05) for mBAS calves compared to CON calves on d7 and d14. No differences in BW or weight gain were observed due to treatment. These results indicate that while behavioral differences were observed, this did not result in improved weight gain in weaned calves. The effectiveness of mBAS as a tool for improving calf welfare during the weaning process warrants further study to confirm its efficacy in higher risk cattle.
Tarter et al. (Wed,) studied this question.