Evaluation of two-stage weaning and trace mineral injection on receiving cattle growth performance and behavior

Rauch, Jordan C; Stokes, Rebecca S; Shike, Daniel W

There were no differences in plasma cortisol concentrations at either sampling time during this study. Lefcourt et al. (1993) stated that diurnal variations in peripheral cortisol in cattle are 1 to 17 ng/ mL. All cortisol concentrations, except for 2SAL steers on d−6, were within this range, suggesting that cattle were within the normal range of daily variations in stress. This is supported by Hickey et al. (2003) and Lefcourt and Elsasser (1995) who also reported no effect of weaning on cortisol response. Due to the limited sampling time points in this experiment and that these calves came from a well-managed herd and were used to human interaction, it is possible that peak cortisol concentrations that may have been associated with weaning were simply missed. It is important to note that day 0 cortisol concentrations would have been reflective of weaning and shipping stress, with all treatments exposed to similar shipping stress.