本文综述了热应激对奶牛繁殖性能的影响及应对措施。热应激会导致奶牛受胎率、妊娠率降低,排卵失败、流产、卵巢囊肿风险增加,还会延长乏情期,影响产奶量,且损害具有积累性。热应激对繁殖的影响包括发情活动减弱、卵母细胞与胚胎发育受阻等。针对此,可通过胚胎移植（夏季鲜胚移植受胎率高于人工授精）、同期排卵技术（提升受胎率）、减少胚胎流失（如配种后注射布舍瑞林）、防治子宫炎（产后保健方案）及治疗卵巢疾病（如用谛诺、布舍瑞林等）等措施改善。同时,需结合防暑降温、营养调整等综合方法,以提高热应激期间奶牛繁殖率。
This paper reviewed the effects of heat stress on dairy cow reproductive performance and corresponding countermeasures. Heat stress can lead to reduced conception and pregnancy rates,ovulation failure,increased risks of abortion and ovarian cysts,prolonged anestrus periods,decreased milk production,and cumulative damage. Its impact on reproduction includes weakened estrus activity and impaired oocyte and embryo development. To address these issues,measures such as embryo transfer （fresh embryo transfer in summer yields higher conception rates than artificial insemination）,ovulation synchronization techniques （improving conception rates）,reducing embryonic loss （e.g.,administering buserelin after breeding）,preventing and treating metritis （postpartum health protocols）,and managing ovarian disorders （e.g.,using Dinoprostone,buserelin,etc.） can be implemented. Additionally,comprehensive approaches such as heat stress mitigation and nutritional adjustments are essential to enhance dairy cow reproductive efficiency during heat stress.
[1] St-Pierre N R,Cobanov B,Schnitkey G. Economic losses from heat stress by US livestock industries[J]. Journal of Dairy Science,2003,86:E52-E77.
[2] Wolfenson D,Roth Z.Impact of heat stress on cow reproduction and fertility[J]. Animal Frontiers,2019,9(1):32-38.
[3] Bernabucci U,Lacetera N,Baumgard L H,et al.Metabolic and hormonal acclimation to heat stress in domesticated ruminants[J]. Animal,2010,4(7):1167-1183.
[4] Rodriguez-Venegas R,Meza-Herrera C A,Robles-Trillo P A,et al. Effect of THI on milk production,percentage of milking cows,and time lying in Holstein cows in northern-arid Mexico[J]. Animals,2023,13(10):1715.
[5] Ealy A,Drost M,Hansen P.Developmental changes in embryonic resistance to adverse effects of maternal heat stress in cows[J]. Journal of Dairy Science,1993,76:2899-2905.
[6] Sakatani M,Kobayashi S,Takahashi M.Effects of heat shock on in vitro development and intracellular oxidative state of bovine preimplantation embryos[J]. Molecular Reproduction and Development,2004,67:77-82.
[7] Demetrio D,Santos R,Demetrio C,et al.Factors affecting conception rates following artificial insemination or embryo transfer in lactating Holstein cows[J]. Journal of Dairy Science,2007,90:5073-5082.
[8] Al-Katanani Y,Drost M,Monson R,et al.Pregnancy rates following timed embryo transfer with fresh or vitrified in vitro produced embryos in lactating dairy cows under heat stress conditions[J]. Theriogenology,2002,58:171-182.
[9] Diskin M G,Murphy J J,Sreenan J M.Embryo survival in dairy cows managed under pastoral conditions[J]. Animal Reproduction Science,2006,96(3-4):297-311.
[10] Wijma R,Stangaferro M L,Kamat M M,et al.Embryo mortality around the period of maintenance of the corpus luteum causes alterations to the ovarian function of lactating dairy cows[J]. Biology of Reproduction,2016,95(5):112.
[11] Dailey R A,Inskeep E K,Lewis P L.Pregnancy failures in cattle:A perspective on embryo loss[C]// Proceedings of the 18th International Conference on Reproduction of Farm Animals. Slovakia,2002:1-8.
[12] 郭志坚,李强. 布舍瑞林在奶牛繁殖生产中的应用[J]. 中国乳业,2025(6):14-20.
[13] Cope D I,Monsivais D.Progesterone receptor signaling in the uterus is essential for pregnancy success[J]. Cells,2022,11(9):1474.
[14] Mirihagalle S,Hughes J R,Miller D J.Progesterone-induced sperm release from the oviduct sperm reservoir[J]. Cells,2022,11(10):1622.
