Comparison between the CIDR or sponge with hormone injection to induce estrus synchronization for twining and sex preselection in Naimi sheep

Abstract The management of sheep reproduction requires the induction and synchronization estrus cycle ovulation for ewe out-of-season and/or synchronized lambing. These managements are based on insertion an intravaginal device controlled internal drug release (CIDR or sponge) then administration a hormonal injection, such as PMSG, eCG, hCG, GnRH. This study aimed to compare impact CIDR sponges, with PMSG GnRH respectively, inducing synchronization, lambing rate, twining, sex preselection rate in Naimi sheep. A total 86 ewes six male rams proven fertility were used this study. results showed that first group had highest 26/28 (92.59%) 35/92 (38.04%) lamb production ratio. offspring ratio was 22/35 males (62.85%) 13/35 female lambs (37.14%). Their twin ratios 9/22 (34.4%), producing 14 (77.77%) 13 females second sponge group’s 16/26 (61.53%). They sired lowest 20/92 (21.73%) 11/20 (55.0%) 9/20 (45.0%) lambs. 4/22 (25% two twins). (22.34%). third control 29/33 (87.87%). produced 37/92 (40.27%) lambs, 22/37 (59.45%) 15/35 (40.45%) eight twins (27.58%), their twins’ equal (50%) Regarding progesterone testosterone hormone levels, no differences during pre- post-intravaginal observed, but estrogen level some pre-insertion. In conclusion, use injection is better management, lambing, rate. approximately same rates.