LRH‐A3 and HCG increase pregnancy rate during timed artificial insemination in dairy cows

• Published in: Animal science journal Vol. 92; no. 1; pp. e13549 - n/a
• Main Authors: Zheng, Peng, Huang, He, Li, Xiaoyu, Huang, Fushuo, Adeniran, Samson Olugbenga, Wang, Ziming, Feng, Rui, Zhang, Guixue
• Format: Journal Article
• Language: English
• Published: Australia Blackwell Publishing Ltd 01.01.2021
• Subjects: Animals; Artificial insemination; Cattle; Cattle - physiology; Chorionic Gonadotropin - administration & dosage; Chorionic Gonadotropin - pharmacology; Dairy cattle; dairy cow; Dairying; Endometrium; Endometrium - metabolism; Epidermal Growth Factor - metabolism; Female; Gonadotropin-releasing hormone; Gonadotropin-Releasing Hormone - administration & dosage; Gonadotropin-Releasing Hormone - pharmacology; Growth factors; HCG; Insemination, Artificial - methods; Interleukin 6; Interleukin-6 - metabolism; Interleukins; Leukemia; Leukemia inhibitory factor; Leukemia Inhibitory Factor - metabolism; LRH‐A3; Luteinizing hormone; Parturition; Pituitary (anterior); Pregnancy; pregnancy rate; Pregnancy, Animal - drug effects; Reproduction (biology); Stimulation, Chemical; timed artificial insemination; Vascular endothelial growth factor; Vascular Endothelial Growth Factor A - metabolism; LRH-A3; dairy cow; timed artificial insemination; HCG; pregnancy rate
• ISSN: 1344-3941; 1740-0929
• DOI: 10.1111/asj.13549

The objective of this study was to use luteinizing hormone‐releasing hormone A3 (LRH‐A3) and human chorionic gonadotrophin (HCG) to improve pregnancy rate of dairy cows during timed artificial insemination (TAI). In experiment 1, the TAI process (0 d, GnRH, 100 μg; 7 d, PGF2α, 0.4 mg; 56 hr, GnRH, 100 μg; 16 hr, AI) was applied to 160 dairy cows on 50th and 60th days after parturition respectively. In experiment 2, 320 postpartum dairy cows were treated with TAI (Group A), TAI + 25 μg LRH‐A3 (Group B), TAI + 1,500 IU HCG 5 days after AI (Group C), and TAI + 25 μg LRH‐A3 + 1,500 IU HCG 5 days after AI (Group D). In experiment 3, endometrial cells were treated with HCG. The results showed that TAI did not affect the pregnancy rate, while LRH‐A3 and HCG increased the pregnancy rate of the cow. HCG of 5 IU/ml and 10 IU/ml increased the expressions of leukemia inhibitory factor but decreased those of interleukin‐6, epidermal growth factor and vascular endothelial growth factor in endometrial cells. This study provided a plan for the use of LRH‐A3 and HCG to increase pregnancy rate during TAI in dairy cows.