The production of (male Blue Catfish Ictalurus furcatus × female Channel Catfish Ictalurus punctatus) F1 hybrids by U.S. catfish farmers has increased dramatically during the last 15 years. However, hybrid catfish production requires hormone‐induced ovulation of female Channel Catfish and remains an inefficient process. Previously, we demonstrated that GnRH IIa given as a two‐dose injection (priming/induction) of 20/80 μg/kg of female body weight resulted in superior ovulation rates for Channel Catfish compared with salmon GnRH IIIa and mammalian LHRHa, which are products that are currently used at commercial catfish hatcheries. The objective of the current study was to determine whether GnRH IIa given at a quarter dose (5/20 μg/kg) would achieve results similar to those that were obtained with the full dose (20/80 μg/kg) and whether the response varied over the spawning season. Trials were conducted at three timepoints during the 2017 spawning season: early (May 1), middle (May 15), or late (June 5). At each timepoint, 20 females received an intraperitoneal injection with a full dose of GnRH IIa and 20 females received an injection with a quarter dose of GnRH IIa. Data were collected for female weight, latency, incidence of ovulation, and stripped eggs weight (g) per kilogram of female body weight. The data indicated that the quarter dose of GnRH IIa (5/20 μg/kg of female body weight) achieved results that were similar to those that were obtained with the full dose of 20/80 μg/kg.

中文翻译：

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促性腺激素释放激素IIa 5 /20-μg/ kg剂量与20 /80-μg/ kg剂量对Channel鱼排卵的影响

（雄性蓝Cat鱼Ictalurus furcatus ×雌性海Cat鱼Ictalurus punctatus的生产）在过去的15年中，美国fish鱼养殖者的F1杂交种急剧增加。但是，杂交cat鱼的生产需要雌性海Channel鱼的激素诱导排卵，这仍然是一个低效的过程。之前，我们证明了GnRH IIa以20/80μg/ kg雌性体重的两次剂量注射（引发/诱导），与鲑鱼GnRH IIIa和哺乳动物LHRHa相比，导致Channel鱼排卵率更高。目前在商业cat鱼孵化场使用。当前研究的目的是确定以四分之一剂量（5/20μg/ kg）给予的GnRH IIa是否会达到与全剂量（20/80μg/ kg）所获得的结果相似的结果，以及该反应是否在产卵季节有所不同。在2017年产卵季节的三个时间点进行了试验：早期（5月1日），中期（5月15日）或晚期（6月5日）。在每个时间点，有20名女性接受腹腔注射全剂量GnRH IIa，而20名女性接受注射四分之一剂量的GnRH IIa。收集有关雌性体重，潜伏期，排卵发生率和每千克雌性体重的去皮卵重量（g）的数据。数据表明，四分之一剂量的GnRH IIa（女性体重为5/20μg/ kg）达到的结果与全剂量20/80μg/ kg获得的结果相似。收集有关雌性体重，潜伏期，排卵发生率和每千克雌性体重的去皮卵重量（g）的数据。数据表明，四分之一剂量的GnRH IIa（女性体重为5/20μg/ kg）达到的结果与全剂量20/80μg/ kg获得的结果相似。收集有关雌性体重，潜伏期，排卵发生率和每千克雌性体重的去皮卵重量（g）的数据。数据表明，四分之一剂量的GnRH IIa（女性体重为5/20μg/ kg）达到的结果与全剂量20/80μg/ kg获得的结果相似。