The effect of transporting, scoring and roping on cortisol concentrations in acclimated roping calves

This study evaluated the effect of transportation, scoring and roping activities on cortisol concentration in acclimated calves. A total of 16 cross-bred Longhorn calves between 4 and 6 months old and ranging in weight between 104 and 136 kg were used. These calves were preconditioned to roping for 6 weeks prior to study and were randomly allotted to treatments based on a Latin Square experimental design with treatments as follows; remaining at farm (farm), transport to arena (transport), twice passing through roping chute but not being roped (score) and twice being roped and tied (rope). Blood samples were collected via jugular vena puncture, received respective treatment and then second blood samples were collected. This experiment was replicated twice (n = 8 calves, per year), and calves were roped twice per day for 3 days per week during the study. The data was analysed by replicate and by pooled data. The mean +/- SE pre-event and change in serum cortisol concentrations (mu g/dL) were: farm (n = 16), 4.5 +/- 0.9, 0.9 +/- 0.6; transport (n = 16), 5.1 +/- 0.6, 0.9 +/- 0.8; score (n = 16), 5.0 +/- 0.5, 1.6 +/- 0.4; rope (n = 15) 4.9 +/- 0.6, 0.5 +/- 0.6. The cortisol concentration was elevated for pre-event samples during week 2 compared with week 4 and this suggests possibly a change in routine may have affected cortisol. However, treatment did not affect (P<0.05) change in cortisol concentration among calves; farm (0.9 +/- 0.6), transport (0.5 +/- 0.6), score (1.7 +/- 0.4), farm (0.9 +/- 0.8). Also, calves weight gain was not different (P>0.05) between groups and averaged 0.32 kg/day, for year 2. These data indicate roping does not increase cortisol concentrations in acclimated calves.