کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5520263 | 1544697 | 2017 | 7 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Long interval prostaglandin as an alternative to progesterone-eCG based protocols for timed AI in sheep Long interval prostaglandin as an alternative to progesterone-eCG based protocols for timed AI in sheep](/preview/png/5520263.png)
- Long PG intervals were associated with higher non return and pregnancy rates.
- Long PG intervals equates progesterone-eCG fertility, prolificacy and fecundity.
- Ovulating ewes was not affected by the protocol used.
To compare the reproductive performance after TAI in ewes synchronized with mid (12 or 13) or long (14-16 d) interval prostaglandin (PG) or progesterone plus eCG (P4-eCG) based protocols, 440 multiparous Corriedale ewes were synchronized with two PG injections administered 12-16 d apart (PG12, PG13, PG14, PG15 and PG16 respectively), or P4-eCG (MAP sponges 14 d and eCG). Cervical TAI (Day 0) was performed with fresh semen. It was evaluated the ovulated ewes (OE, %) and the ovulation rate (OR) on Day 8 by trans-rectal ultrasonography, the rate of non-return to service between Days 13 and 21 by painted rams, and the pregnancy rate, prolificacy and fecundity on Day 60 by trans-abdominal ultrasonography. No significant differences were found in OE among groups (PÂ >Â 0.05), but P4-eCG achieved higher OR (PÂ <Â 0.05) compared to PG protocols, without differences among them (PÂ >Â 0.05). Similar NRR-21, pregnancy and fecundity were observed among PG15 (64.3, 62.9 and 84.3), PG16 (59.7, 59.7 and 77.8) and P4-eCG (70.3, 66.2 and 95.9), but higher compared to PG12 (42.5, 39.7 and 52.1) and PG13 group (44.0, 40.0 and 48.0, respectively; PÂ <Â 0.05). PG14 achieved intermediate results compared to other groups. No differences were found in prolificacy among groups (PÂ >Â 0.05), except PG13 that was lower compared to P4-eCG (PÂ <Â 0.05). In conclusion, long interval between PG injections (15 or 16 d) determined better reproductive outcome that mid interval (12 or 13 d), equating the P4-eCG based protocol after cervical TAI with fresh semen during the breeding season in sheep.
Journal: Animal Reproduction Science - Volume 180, May 2017, Pages 78-84