Abstract
POOR reproductive performance of domestic farm animals in hot, humid environments has been a generally accepted premise. Seath and Staples (1941), Stott and Williams (1962) and Long, Nipper and Vincent (1969) reported significantly lower conception rates in both dairy and beef cattle herds during the summer. Alliston and Ulberg (1961) and Dutt (1963) found that exposure of ewes to high temperature shortly after mating had the greatest detrimental effect on embryonic survival. The same effect was found in swine (Tompkins, Heidenreich and Stob, 1967; Edwards et al., 1968). This study was initiated to determine the effect of high environmental temperature, immediately following breeding, on the conception rate of British beef cattle. Materials and Methods Forty-three postpuberal purebred Hereford heifers, 18 to 24 months of age and weighing 275 to 325 kg, were used to compare two environmental temperature conditions. In treatment 1, the heifers were placed in a climate control chamber maintained at 32.2 C and 65% relative humidity for 72 hr. immediately following breeding. In the second treatment, the heifers were kept at 21.1 C and 65% relative humidity for the same 72-hr. interval. Copyright © 1971. American Society of Animal Science . Copyright 1971 by American Society of Animal Science.