Impact of summer heat stress on the thermal environment of bovine female genital tract.

Summer heat stress (HS) is associated with a reduction in conception rate, increase in services per conception, and early embryonic death. However, the impact of summer HS on the thermal environment of different regions of the bovine female genital tract remains unknown. This study aimed to elucidate the effect of summer HS on the thermal environment of different regions of the genital tract in the cow.

Presence of a temperature gradient among genital tract portions and the thermal changes within these portions over the estrous cycle in beef cows.

The aim of the present study was to describe the temperature of the different portions of the female genital tract and their relation to rectal temperature and to investigate the effect of steroid hormones profiles on these variables over the estrous cycle in cattle. Four nonpregnant Japanese Black cows were investigated daily over two successive estrous cycles using a digital thermometer with a long probe and rounded-end sensor to record the temperature of the rectum (RT), vagina (VT), cervix (CT), uterine body (UBT) and uterine horns (UHT). Blood samples were collected immediately before temperature recording to assay peripheral levels of progesterone (P(4)) and estradiol-17β (E(2)).