Sheep wool cortisol as a retrospective measure of long-term HPA axis activity and its links to body mass.

摘要: Hair cortisol analysis has been suggested as a powerful retrospective measure of long-term hypothalamic-pituitary-adrenal (HPA) axis activity in numerous mammal species. In contrast, research evaluating the use wool marker HPA is still scarce, and differs from hair number ways. Here, we assess repeatability differences concentrations (WCCs) across (i) shaft, (ii) two body locations, (iii) time, 33 barren Welsh mountain ewes (Ovis aries). We also (iv) investigated effects grazing-related changes mass on WCCs (v) assessed washing procedure during sample preparation WCCs. Cortisol were repeatable but differed significantly shaft indicating that, provided growth rate known, single per individual could be used "timeline." higher shoulder than back samples, no correlation between these locations was found, highlighting importance sampling same location for repeated measures. An increase grazing corresponded with decrease WCCs, which negatively correlated (and positively age), suggesting that can condition nutritional status sheep. Interestingly, found washed compared unwashed samples discuss implications this finding future work. Overall, our study revealed significant within- between-individual highlights advantages methodological considerations using