The effects of cold stress on neonatal calves. I. Clinical condition and pathological lesions.

Newborn Holstein-Friesian calves were cold stressed by immersion in water at 15 to 17 degrees C until the core body temperature was lowered by 10 degrees C. Non-cold stressed calves were immersed in water at thermoneutral temperature (35 to 37 degrees C). The time required to lower the core body temperature of the cold stressed calves by 10 degrees C was 172 +/- 87 minutes (mean +/- SD). The time required for the core body temperature of the cold stressed calves to return to normal after immersion was 400 +/- 140 minutes (mean +/- SD). Differences were observed between cold and noncold stressed calves in the shivering response during immersion and the clinical condition after immersion. Cold-induced pathological lesions were confined to tissues located peripherally, particularly in the hind legs. Significant differences were observed between cold and noncold stressed calves in the incidence of subcutaneous edema in the ventral sternum (P less than or equal to 0.025), subcutaneous hemorrhage in the hind legs (P less than or equal to 0.025), synovitis (P less than or equal to 0.025) and hemorrhage (P less than or equal to 0.05) of the synovial membranes of the hock joints and hemorrhage (P less than or equal to 0.05) into the hock joint cavities.