Dexamethasone reduces transport-induced weight losses in beef calves

Abstract

Dexamethasone was administered intramuscularly at two dose levels (Trial 1 = 0.088 mg kg -1 ; Trial 2 = 10 mg per calf) to beef calves (Trial 1, n = 60; Trial 2, n = 58) prior to transport by road for 10 and 8 h, to test the effect on transport-induced weight losses. Calves lost significant weight over the transport periods (P < 0.001) but dexamethasone-treated calves lost significantly less weight than control animals (P < 0.004). The relationship between salivary dexamethasone concentrations and weight losses in Trial 1 exhibited a significant trend (r = 0.47, P < 0.06). The correlation of administered dose of dexamethasone (mg kg -1 ) with weight losses in Trial 2 was significant (r = 0.5, P < 0.006). Dexamethasone administration prior to long-haul transport reduced transport-induced weight losses, and may be an effective method of mitigating transport stress.Key words: Transport, beef calves, dexamethasone, weight losses, salivary cortisol, salivary dexamethasone