Souza A H, Cunha A P, Silva E P B, Gümen A, Ayres H, Guenther J N, Wiltbank M C
Department of Dairy Science, University of Wisconsin, Madison, WI, USA.
Theriogenology. 2009 Jul 15;72(2):271-9. doi: 10.1016/j.theriogenology.2009.02.016. Epub 2009 Apr 24.
This study evaluated whether the four gonadorelin products that are commercially available in the United States produce comparable ovulation responses in lactating cows. Dairy cows at 7 d after last gonadotropin-releasing hormone (GnRH) treatment of Ovsynch (Day 7), with a corpus luteum (CL) > or =15 mm and at least one follicle > or =10mm, were evaluated for response to GnRH treatment. Selected cows were randomized to receive (100 microg; im): (1) Cystorelin (n=146); (2) Factrel (n=132); (3) Fertagyl (n=140); or (4) Ovacyst (n=140). On Day 14, cows were examined for ovulation by detection of an accessory CL. Circulating luteinizing hormone (LH) concentrations were also evaluated in some cows after treatment with 100 microg (n=10 per group) or 50 microg (n=5 per group) GnRH. Statistical analyses were performed with the procedures MIXED and GLIMMIX of the SAS program. Percentage of cows ovulating differed (P<0.01) among groups, with that for Factrel being lower (55.3%) than that for Cystorelin (76.7%), Fertagyl (73.6%), or Ovacyst (85.0%). There was no effect of batch, parity, or follicle size on ovulation response, but increasing body condition score decreased ovulation response. There was a much greater LH release in cows treated with 100 microg than in those treated with 50 microg, but there were no detectable differences among products in time to LH peak, peak LH concentration, or area under the LH curve and no treatment effects nor treatment by time interactions on circulating LH profile. Thus, ovulation response to Factrel on Day 7 of the cycle was lower than that for other commercial GnRH products, although a definitive mechanism for this difference between products was not demonstrated.
本研究评估了美国市面上可买到的四种促性腺激素释放激素产品对泌乳奶牛是否能产生类似的排卵反应。在末次促性腺激素释放激素（GnRH）处理（Ovsynch方案第7天）后7天的奶牛，若其黄体（CL）≥15毫米且至少有一个卵泡≥10毫米，则评估其对GnRH处理的反应。挑选出的奶牛被随机分组接受（100微克；肌肉注射）：（1）促排灵（n = 146）；（2）法莫林（n = 132）；（3）弗他利（n = 140）；或（4）卵胞素（n = 140）。在第14天，通过检测副黄体来检查奶牛是否排卵。部分奶牛在接受100微克（每组n = 10）或50微克（每组n = 5）GnRH处理后，还评估了其循环促黄体生成素（LH）浓度。使用SAS程序的MIXED和GLIMMIX过程进行统计分析。各处理组奶牛的排卵百分比存在差异（P < 0.01），法莫林组（55.3%）低于促排灵组（76.7%）、弗他利组（73.6%）或卵胞素组（85.0%）。批次、胎次或卵泡大小对排卵反应没有影响，但体况评分增加会降低排卵反应。接受100微克处理的奶牛比接受50微克处理的奶牛促黄体生成素释放量大得多，但各产品在促黄体生成素峰值出现时间、促黄体生成素峰值浓度或促黄体生成素曲线下面积方面没有可检测到的差异，且在循环促黄体生成素谱上没有处理效应或处理与时间的交互作用。因此，在周期第7天对法莫林的排卵反应低于其他市售GnRH产品，尽管未证明产品间这种差异的确切机制。
