科研之友
微信
新浪微博
Facebook
分享链接
摘要
Contents The aim of this study was to evaluate the effect of porcine luteinizing hormone (pLH) given at oestrous onset in gilts, by different routes and doses, on the interval between onset of oestrus and ovulation (IOEO) and reproductive performance using a single fixed-time artificial insemination (FTAI). A total of 153 gilts were submitted to oestrous detection at 8-h intervals and assigned to three groups: control - without hormone application and inseminated at 0, 24 and 48h after oestrous onset; VS2.5FTAI - 2.5mg pLH by the vulvar submucosal route at oestrous onset and a single FTAI 16h later; IM5FTAI - 5mg pLH by the intramuscular route at oestrous onset and a single FTAI 16h later. More VS2.5FTAI gilts (47.1%; p<0.05) ovulated within 24h after oestrous onset than control gilts (25.5%) whereas IM5FTAI gilts had an intermediate percentage (31.4%; p>0.05). The IOEO tended to be shorter (p=0.06) in VS2.5FTAI (30.2 +/- 1.4h) than in control (34.7 +/- 1.4h) gilts, but there was no difference (p>0.05) between control and IM5FTAI (32.8 +/- 1.4h) gilts. Farrowing rate was not different (p>0.05) among treatments. Total born piglets (TB) was lower (p<0.05) in VS2.5FTAI (12.3 +/- 0.4) than in control gilts (14.1 +/- 0.4), whereas intermediate TB was observed in IM5FTAI gilts (13.3 +/- 0.4). Due to the advancement of ovulation, reduction of the hormonal dose and the ease of application, the vulvar submucosal route would be the best option for FTAI protocols, but their negative impact on litter size remains to be elucidated. Taking into account the good fertility results obtained in IM5FTAI gilts whose ovulation was not advanced, the possibility of a single FTAI without any hormonal treatment should be further investigated, to establish reliable FTAI protocols for gilts.
- 出版日期2014-10
