Biehl Marcos V, Ferraz Junior Marcos V C, Ferreira Evandro M, Polizel Daniel M, Miszura Alexandre A, Barroso José P R, Oliveira Gabriela B, Bertoloni Analisa V, Pires Alexandre V
Department of Animal Science, Luiz de Queiroz College of Agriculture, University of São Paulo, Pádua Dias Avenue, n. 11, PO Box 09, Piracicaba, São Paulo, 13418-900, Brazil.
Department of Nutrition and Animal Production, College of Veterinary and Animal Science, University of São Paulo, Duque de Caxias North Avenue, n. 225, Pirassununga, São Paulo, 13635-000, Brazil.
Trop Anim Health Prod. 2017 Aug;49(6):1303-1308. doi: 10.1007/s11250-017-1329-1. Epub 2017 Jun 12.
This study aimed to determine whether reproductive performance of ewes submitted to laparoscopic timed artificial insemination (TAI) would be similar to ante meridiem (AM)/post meridiem (PM) rule and assisted natural mating (NM), and whether GnRH may enhance the pregnancy rate in TAI. In experiment I, 191 non-lactating ewes were synchronized, then TAI was performed either 48 h after progesterone (P4) removal (TAI-48 h) or 12 h after estrus detection (AM/PM); moreover, some ewes were submitted to NM (NM) as control treatment. In experiment II, 247 non-lactating ewes were allocated in five treatments, a control (no-GnRH on protocol) and four treatments arranged in a factorial design 2 × 2. The factors were time and dose of GnRH: ewes that received either 10 μg (TAI-10 μg-36 h) or 25 μg of GnRH (TAI-25 μg-36 h) 36 h after P4 removal and ewes that received either 10 μg (TAI-10 μg-48 h) or 25 μg of GnRH (TAI-25 μg-48 h) at time of insemination, 48 h after P4 removal. In experiment I, pregnancy rate in TAI-48 h was lower (P = 0.03) than AM/PM and NM. Moreover, the probability of pregnancy in TAI-48 h was higher (P = 0.06) in ewes detected in estrus early. In experiment II, the use of GnRH in TAI protocols increased (P < 0.01) pregnancy rate at synchronization, and TAI-25 μ-48 h and TAI-10 μg-36 h treatments increased (P = 0.02) pregnancy rate compered to TAI-10 μg-48 h. We conclude that TAI decreased pregnancy rate compered to NM and AM/PM, which may be improved by GnRH use in TAI to synchronize ovulation.
本研究旨在确定接受腹腔镜定时人工授精（TAI）的母羊的繁殖性能是否与上午/下午规则及辅助自然交配（NM）相似，以及促性腺激素释放激素（GnRH）是否可提高TAI的妊娠率。在实验I中，对191只非泌乳母羊进行同期发情处理，然后在去除孕酮（P4）后48小时（TAI - 48小时）或发情检测后12小时（上午/下午）进行TAI；此外，一些母羊接受NM（NM）作为对照处理。在实验II中，将247只非泌乳母羊分为五种处理，一种对照（方案中不使用GnRH）和四种采用2×2析因设计的处理。因素为GnRH的时间和剂量：在去除P4后36小时接受10μg（TAI - 10μg - 36小时）或25μg GnRH（TAI - 25μg - 36小时）的母羊，以及在去除P4后48小时授精时接受10μg（TAI - 10μg - 48小时）或25μg GnRH（TAI - 25μg - 48小时）的母羊。在实验I中，TAI - 48小时的妊娠率低于上午/下午和NM（P = 0.03）。此外，早期发情检测到的母羊中TAI - 48小时的妊娠概率更高（P = 0.06）。在实验II中，在TAI方案中使用GnRH可提高同期发情时的妊娠率（P < 0.01），并且与TAI - 10μg - 48小时相比，TAI - 25μg - 48小时和TAI - 10μg - 36小时处理可提高妊娠率（P = 0.02）。我们得出结论，与NM和上午/下午相比，TAI降低了妊娠率，在TAI中使用GnRH来同步排卵可能会改善这一情况。
