热应激是影响奶牛繁殖性能的关键环境因素,可导致奶牛内分泌紊乱、卵巢与子宫功能受损、发情行为异常等问题,显著降低受胎率与繁殖效率。本文系统阐述了热应激对奶牛繁殖系统的生理影响,重点探讨了生殖激素（如GnRH、孕酮、FSH/LH、PGF2α）在缓解热应激中的调控策略,包括激素使用方案的优化、剂量调整及其与环境调控、营养支持和精准监测等综合管理措施的协同应用。实践表明,科学运用激素干预并结合综合管理,可有效提升热应激条件下奶牛的繁殖性能。
Heat stress is a critical environmental factor affecting the reproductive performance of dairy cows,leading to endocrine disorders,impaired ovarian and uterine functions,abnormal estrus behaviors,and significantly reduced conception rates and reproductive efficiency. This paper systematically elaborated on the physiological impacts of heat stress on the reproductive system of dairy cows,with a focus on regulatory strategies involving reproductive hormones（such as GnRH,progesterone,FSH/LH,and PGF2α）. These strategies include the optimization of hormone administration protocols,dosage adjustments,and their synergistic application with comprehensive management measures such as environmental control,nutritional support,and precision monitoring. Practical evidence demonstrates that scientifically applied hormonal interventions,combined with integrated management,can effectively enhance the reproductive performance of dairy cows under heat stress conditions.
[1] 李蓓蓓,李秋凤,杜柳柳,等. 奶牛热应激的机制及其评定指标[C]//中国畜牧兽医学会养牛学分会. 中国畜牧兽医学会养牛学分会第八届全国会员代表大会暨2015年学术研讨会论文集.保定:河北农业大学动物科技学院,2015:707-710.
[2] Polsky L,Von Keyserlingk M A G. Invited review:Effects of heat stress on dairy cattle welfare[J]. Journal of Dairy Science,2017,100(11):8645-8657.
[3] B E H A,B U S N A,C S R A,et al. Fetal programming in dairy cows:Effect of heat stress on progeny fertility and associations with the hypothalamic-pituitary-adrenal axis functions[J]. Animal Reproduction Science,2020,216:106349.
[4] 施振旦,郭文军,黄运茂,等. 热应激对奶牛繁殖力的影响及应对措施[J]. 中国奶牛,2006(11):20-23.
[5] Wolfenson D,Roth Z.Impact of heat stress on cow reproduction and fertility[J]. Animal Frontiers,2019,9(1):32-38.
[6] Roth Z.Heat Stress,the Follicle,and Its Enclosed Oocyte:mechanisms and potential strategies to improve fertility in dairy cows[J]. Reproduction in Domestic Animals,2008,43(S2):172-179.
[7] Wilson S J,Marion R S,Spain J N,et al.Effects of controlled heat stress on ovarian function of dairy cattle. 1. Lactating Cows[J]. Journal of Dairy Science,1998,81(8):2124-2131.
[8] Wolfenson D,Roth Z.Impact of heat stress on cow reproduction and fertility[J]. Animal Frontiers,2019,9(1):32-38.
[9] Badinga L,Collier R J,Thatcher W W,et al.Effects of climatic and management factors on conception rate of dairy cattle in subtropical environment[J]. Journal of Dairy Science,1985,68(1):78-85.
[10] Wolfenson D,Lew B J,Thatcher W W,et al.Seasonal and acute heat stress effects on steroid production by dominant follicles in cows[J]. Animal Reproduction Science,1997,47(1-2):9-19.
[11] Niswender G D,Juengel J L,Silva P J,et al.Mechanisms controlling the function and life span of the corpus luteum[J]. Physiological Reviews,2000,80(1):1-29.
[12] Roth Z.Involvement of apoptosis in disruption of developmental competence of bovine oocytes by heat shock during maturation[J]. Biology of Reproduction,2004,71(6):1898-1906.
[13] Spencer T E,Johnson G A,Bazer F W,et al.Fetal-maternal interactions during the establishment of pregnancy in ruminants[J]. Society of Reproduction and Fertility Supplement,2007,64:379-396.
[14] Guzeloglu A,Ambrose J D,Kassa T,et al.Long-term follicular dynamics and biochemical characteristics of dominant follicles in dairy cows subjected to acute heat stress[J]. Animal Reproduction Science,2001,66(1-2):15-34.
[15] Sakatani M,Alvarez N V,Takahashi M,et al.Consequences of physiological heat shock beginning at the zygote stage on embryonic development and expression of stress response genes in cattle[J]. Journal of Dairy Science,2012,95(6):3080-3091.
[16] 兽医范儿. 热应激对奶牛繁殖的影响[EB/OL].https://mp.weixin.qq.com/s/__此处为示例链接,2022-06-05.
[17] 搜狐. 精子质量&发情表达丨热应激对奶牛繁殖的影响(一)[EB/OL].https://www.sohu.com/a/334306938_660171,2019-08-16.
[18] Pursley J R,Mee M O,Wiltbank M C.Synchronization of ovulation in dairy cows using PGF2α and GnRH[J]. Theriogenology,1995,44(7):915-923.
[19] Wiltbank M C,Pursley J R.The cow as an induced ovulator:Timed AI after synchronization of ovulation[J]. Theriogenology,2014,81(1):170-185.
[20] 张旭,王迪铭,刘建新. 奶牛对热应激的适应性机制及牧场缓解热应激策略[J]. 中国畜牧杂志,2024,60(1):6-13.
[21] 杨子程. GnRH对荷斯坦奶牛繁殖力与卵泡囊肿影响的研究[D]. 呼和浩特:内蒙古农业大学,2023.
