Environmental enrichment has been proven to improve the welfare of many captive animal species including dairy cattle. Most research studies have focused on social and nutritional enrichment but very little is known about the effects of sensory enrichment on the welfare of dairy calves. Appeasing pheromones have been used to reduce stress and anxiety levels in different domesticated species including cats, dogs, horses and pigs. This study aimed to evaluate the effects of a synthetic analogue of the bovine appeasing pheromone (BAP)  on dairy calves’ physiological stress responses and overall welfare during the critical early life period from birth through to milk weaning at around 8 weeks of age. Particular attention was given to neuroendocrine stress response as measured by salivary cortisol (acute stress) and hair cortisol (chronic stress), both funded by UFAW.

The project responded to the need for welfare enhancing strategies in artificial dairy calf rearing systems, where early separation from the dam, social isolation, restricted diets and abrupt milk weaning are common practices. Salivary and cortisol levels were measured every 2 weeks from the first week after the calves were born to 12 weeks old, and provided valuable insights into how BAP influenced stress adaptation when calves were treated with this substance or a placebo. While average cortisol levels did not differ significantly between treatment groups, patterns of response suggested that BAP may buffer the endocrine stress response associated with milk weaning. Specifically, placebo-treated calves exhibited a significant spike in salivary cortisol after full milk weaning, while this rise was not present in BAP-treated calves. A similar trend was observed in age-based comparisons, where BAP-treated calves showed reduced cortisol levels compared to placebo calves at some post-weaning ages. Although no statistically significant differences in hair cortisol levels were found between groups, it is important to note the variability introduced by practical sampling limitations (e.g., hair colour and inability to test regrowing hair). These limitations are well documented in the literature and were addressed analytically.

Garcia-Alvarez J, Teruel E, Cozzi A, Harris E, Rutter SM, Beaber A 2025 Effects of a synthetic analogue of the bovine appeasing pheromone on the overall welfare of dairy calves from birth through weaning. Journal of Dairy Science 108(2), 1964-1977. https://doi.org/10.3168/jds.2024-25452.