The long exposure to heat negatively changes performance and productivity of animals, particularly when heat stress is associated with gestation. Indeed, little is known about the negative effects of long-term heat stress on the final gestation of dairy goats. In this context, the physiological and cellular responses of Saanen goats submitted to heat stress (37°C from 10:00 to 16:00 h) were investigated from day 60th pre-partum to day 60th post-partum. At final gestation, 46 pregnant Saanen goats were randomly assigned to the treatments: control (CT; thermal neutral conditions) and heat stress (HS; climatic chamber). After partum, all experimental goats were maintained in thermal neutral conditions. The rectal, dorsal, mammary temperatures and respiratory frequency, cortisol release, milk yield, milk quality, and the genes HSP60, HSP70, HSP90, Glucocorticoid receptor and ACTHR. Goats subjected to HS showed significantly (P < 0.05) higher rectal, dorsal, and mammary temperatures and significantly mobilized the increase of respiratory frequency to lose heat as compared to CT goats. The HS challenge significantly increased cortisol release from day 15th pre-partum to day 15th post-partum. CT goats produced more milk than HS from weeks 4 to 10 of lactation (P <0.001), with no difference in milk quality. However, on day 15th post-partum, there was a significant effect of HS treatment on the expression of HSP70 and ACTHR genes as compared to CT treatment, confirming the long-term effect of HS on Saanen goats. In conclusion, the physiological parameters studied increased pre-partum in the hottest hour, and cortisol peaked on day 15 pre-partum for heat-stressed goats. Although on the 15th day post-partum, all goats were in thermal comfort, and the physiological parameters were within the normal range, the concentration of cortisol continued to be significantly higher for goats submitted to thermal stress. Indeed, milk yield was greater for goats subjected to pre-partum thermal comfort. Furthermore, the expression of HSP70 and ACTHR genes on peripheral blood mononuclear cells are interesting biomarkers for studying the long-term effect of heat stress on Saanen goats.

长时间暴露在高温下会对动物的性能和生产力产生负面影响，特别是当热应激与妊娠相关时。事实上，关于长期热应激对奶山羊最终妊娠的负面影响知之甚少。在这种情况下，从产前第 60 天到产后第 60 天，研究了萨能山羊在热应激（10:00 至 16:00 时 37°C）下的生理和细胞反应。在最后的妊娠期，46 只怀孕的 Saanen 山羊被随机分配到处理组：对照（CT；热中性条件）和热应激（HS；气候室）。产后，所有实验山羊都保持在热中性条件下。直肠、背侧、乳房温度和呼吸频率、皮质醇释放、产奶量、奶质量和基因 HSP60、HSP70、HSP90、糖皮质激素受体和ACTHR。经受 HS 的山羊显着 (P < 0.05) 与 CT 山羊相比，直肠、背侧和乳房温度较高，并显着调动呼吸频率的增加来散热。从产前第 15 天到产后第 15 天，HS 挑战显着增加了皮质醇的释放。CT 山羊在泌乳第 4 至 10 周产奶量高于 HS（P <0.001），奶质无差异。然而，在产后第 15 天，HS 治疗对HSP70和ACTHR的表达有显着影响基因与 CT 治疗相比，证实了 HS 对 Saanen 山羊的长期影响。总之，研究的生理参数在产前最热的时候增加，而热应激山羊的皮质醇在产前第 15 天达到峰值。虽然在产后第15天，所有山羊都处于热舒适状态，生理参数在正常范围内，但承受热应激的山羊皮质醇浓度持续显着升高。事实上，产前热舒适的山羊产奶量更高。此外，HSP70 和 ACTHR 基因在外周血单个核细胞上的表达是研究热应激对 Saanen 山羊的长期影响的有趣生物标志物。