Evidence for Temporal Effect of Exposure to Heat Stress During Various Developmental Stages on Productive and Reproductive Performance As Well As Thermotolerance of Reproductive Performance in the Offspring in Dairy Cows Publisher



Zarabadipour S ; Mobedi E ; Allahyari I ; Gharagozlou F ; Vojgani M ; Hemmati Baghbanani R ; Akbarinejad A ; Akbarinejad V
Source: Journal of Thermal Biology Published:2025

Abstract

Prenatal and neonatal exposure to heat stress could negatively affect postnatal reproductive performance in cows. Yet regarding this effect, it has not been differentiated whether the cows were unexposed or exposed to heat stress during postnatal period. Therefore, the present study investigated reproductive performance of offspring (n = 8774) conceiving in the first month of various seasons of year considering whether or not they were exposed to heat stress around their first life (nulliparous offspring) and postpartum (primiparous offspring) insemination. Developmental stages were assumed as preconceptional, first, second and third trimesters of fetal and neonatal periods. The longest duration of exposure to heat stress was the second trimester of fetal period in spring group, the first trimester of fetal period in summer group, preconceptional and neonatal periods in fall group, and the third trimester of fetal period in winter group (P < 0.05). When exposure to heat stress did not occur around the first insemination, first service conception risk (FSCR) was the greatest, intermediate, and least in spring and summer, winter, and fall groups, respectively, in nulliparous and primiparous offspring (P < 0.05). Yet when exposure to heat stress occurred around the first insemination, FSCR was the least, intermediate, and greatest in spring and summer, winter, and fall groups, respectively, in nulliparous offspring. It was also less in spring and summer groups than fall and winter groups in primiparous offspring (P < 0.05). In conclusion, the present study showed temporal developmental effects of heat stress not only on reproductive performance but also on thermotolerance of reproductive performance in the resultant progeny in cattle. © 2025 Elsevier B.V., All rights reserved.