Hair cortisol concentration in veal calves reared under two different welfare production labels

The hypothesis of this study was that veal calves reared under enhanced welfare standards undergo less stress than calves raised in a conventionally system that meets the minimal standards of the Swiss animal welfare legislation, and that this difference is reflected by differences in hair cortisol concentrations and the size, weight and total cortisol concentration of the adrenal glands. A total of 100 veal calves reared under two different animal welfare production labels were used; the labels differed with respect to stocking density and access to an outdoor area and pasture. The production labels included Quality Management and Naturafarm. Hair samples for cortisol measurement were collected from all calves and the adrenal glands were obtained at slaughter. The left adrenal gland was used for cortisol measurement and the right gland was used for histological and morphometric measurements. The median hair cortisol concentrations of the two production groups were 2.4 and 2.3 pg/mg hair, which did not differ significantly. Likewise, the median cortisol concentration of the adrenal cortex (1.7 and 1.6 μg/g), the total adrenal cortisol content (4.8 and 4.7 μg), the weights of the cortex (3.2 and 3.1 g) and medulla (1.7 and 1.7 g) and the thickness of the zona fasciculata (1430 and 1532 μm) did not differ significantly between groups. Thus, it appears that the calves of the two production labels did not suffer obvious stress. This finding notwithstanding, all veal calves deserve to be reared under optimised animal-appropriate welfare conditions.