Field synchronization of Ethiopian Highland sheep for fixed time artificial insemination: improvement of conception rate with a double injection of prostaglandin at 11 days

Published Date
September 04, 2020
Type
Journal Article
Field synchronization of Ethiopian Highland sheep for fixed time artificial insemination: improvement of conception rate with a double injection of prostaglandin at 11 days
Authors:
Shanbel Besufkad Yeshaw
Simret Betsha, Chekole Demis, Tesfaye Zewude, Mariem Rouatbi, Tesfaye Getachew, Aynalem Haile, Barbara Rischkowsky, Mourad Rekik

The study investigated, for fixed time artificially inseminated (AI) Menz ewes in field trials, the reproductive
performance of prostaglandin-based treatments simultaneously to the standard ‘P4+eCG’ protocol. A total
of 483 Menz ewes were assigned to either the ‘P4+eCG’ protocol, using progesterone impregnated
intravaginal sponges in combination with equine chorionic gonadotropin (eCG) injection at sponge
withdrawal, or the ‘PGFs’ treatment where sheep received a single injection of prostaglandin or ‘PGF7’
and ‘PGF11’ where ewes were synchronized with 2 injections of prostaglandin 7 or 11 days apart,
respectively. AI was implemented with fresh semen at 55 ± 1 h after the end of the hormonal
treatment. Conception rate (CR; 60.87 ± 4.2) was highest for PGF11 ewes (P < 0.05); PGFs ewes had the
lowest CR (34.07 ± 4.1). Other factors did not affect variation in CR (P > 0.05). A higher proportion of
ewes in the P4+eCG group yielded twins and triplets compared to the 3 prostaglandin-based protocols
(P < 0.01). Nevertheless, a higher (P = 0.02) proportion (17.11 ± 4.3) of PGF11 ewes yielded twins by
comparison to their PGF7 counterparts (2.50 ± 2.5). PGF-based protocol with 2 injections 11 days apart,
preceded by a careful selection of non-pregnant ewes for cervical fixed-time AI, is a feasible
reproductive management for sheep breeding programmes in Ethiopia.

Citation:
Shanbel Yeshaw, Simret Betsha, Chekole Demis, Tesfaye Zewude, Mariem Rouatbi, Tesfaye Getachew, Aynalem Haile, Barbara Rischkowsky, Mourad Rekik. (4/9/2020). Field synchronization of Ethiopian Highland sheep for fixed time artificial insemination: improvement of conception rate with a double injection of prostaglandin at 11 days. Journal of Applied Animal Research, 48 (1), pp. 413-418.
Keywords:
menz sheep
prostaglandins
conception rate
synchronization
artificial insemination