Short Communication: Factors Affecting Hair Cortisol Concentrations in Lactating Dairy Cows

The study examined factors influencing hair cortisol concentrations in lactating Holstein cows, focusing on hair color, sampling location, and processing method. It found that white hair had higher cortisol levels than black hair, with the tail switch location showing the highest concentrations due to its faster growth and consistent white color. The ball mill processing method extracted more cortisol than using scissors. Multiparous cows had slightly higher cortisol levels, and cortisol concentrations decreased with increased days in milk, indicating potential as a stress indicator post-parturition. The study involved 37 cows, highlighting the importance of standardized sampling methods for consistent cortisol analysis.