α-Casozepine supplementation shows no effect on foals’ growth and cortisol levels before and after weaning

Abstract

OBJECTIVE The goal of this study was to determine whether oral administration of α-casozepine (Zylkene) supplementation decreases the risk of disease in foals, as measured through salivary cortisol levels, temperature, clinical signs of disease, and body weight before and after weaning. ANIMALS 20 Thoroughbred foals were observed over 10 weeks, beginning 14 days prior to the time of weaning. METHODS Experimental foals were randomly selected and given α-casozepine daily for 10 weeks, while the controls received a placebo with the same frequency as the experimental group. The average daily height and weight gain were calculated to examine the effects of α-casozepine before and after weaning. Salivary cortisol levels were also compared before versus after weaning. RESULTS There was no statistically significant difference in average daily height/weight gain or cortisol levels between the α-casozepine group and the control before and after weaning. However, the α-casozepine group had numerically less of a decline in height and growth compared to the control. This suggests that with further study Zylkene may decrease losses in foal growth rate. CLINICAL RELEVANCE The weaning process is one of the largest stressors in a young horse’s life. This abrupt process can contribute to an increased risk of disease and even morbidity. Other major stressors including separation from the mare, diet change, and new social groups can also lead to animal health and welfare concerns, as well as economic losses in weanling foals. However, further study is required to determine the benefits of α-casozepine on equine stress and health.