Changes in Respiration and Heart Rates, Body Temperatures, Plasma Lactic Acid Levels and Plasma Creatinine Levels Caused by Stress in Dairy Cattle

Abstract

Conceivably, one of the factors involved in milk production is the ability of the animal to adjust itself to a changing environment, and differences in levels of production between animals can in part be attributable to differences in abilities to make environmental adjustment. It is also to be expected that with a fuller knowledge of the effect of environmental factors upon levels of production more favorable conditions can be provided. This report deals with observations on the effects of low ambient temperature, exercise, intermittent electrical shock, adrenaline injections, dehorning, and parturition upon rectal temperature, respiration and heart rates, and plasma lactic acid and creatinine levels.