Evaluation of Hair Characteristics and Animal Age on the Impact of Hair Cortisol Concentration in Feedlot Steers

This study on 19 beef feedlot steers found that older steers had higher hair cortisol concentrations than younger ones, regardless of hair color. There was no significant difference in cortisol levels between older steers with black or white hair. A weak positive correlation existed between hair cortisol concentration and hair length, but hair growth duration did not significantly affect cortisol levels. The study concluded that age and hair color significantly influenced hair cortisol concentrations, suggesting these factors should be considered when using hair cortisol as a measure of chronic stress in cattle. The study was limited by its small sample size and the use of fistulated cattle, indicating a need for further research.