OBSERVATIONS ON THE EFFECTS OF XYLAZINE IN NATURALLY AND ARTIFICIALLY REARED CALVES

Abstract

Xylazine, when administered to calves separated from the cow at birth, in a dose recommended to cause recumbency, had the desired sedative effect within five minutes. When the same dose was administered to calves reared naturally on their dams, i.e. suckled, the sedative effect was greatly attenuated. The results suggest that the early-weaning of calves and its associated rearing procedures can modify the pharmacology of the central nervous system; in particular their response to a sedative such as xylazine.