Effects of cloprostenol and flurogestone acetate sponge on embryo yields and quality in indigenous ewes in Bangladesh

Abstract

The effects of two doses of cloprostenol and two doses of flurogestone acetate sponge on the onset of oestrus, and embryo recovery and quality were evaluated. Thirty-two indigenous ewes (Wera breed) were allocated into four groups of eight. All ewes were synchronised with 100 µg (Group I) or 175 µg (Group II) cloprostenol injection, 9 days apart, or insertion of intravaginal sponges containing 30 mg (Group III) or 45 mg (Group IV) flurogestone acetate (FGA) for 12 days. The ewes were superovulated with 600 IU PMSG intramuscularly 10 days after the second cloprostenol injection or immediately after sponge removal on Day 12. After the detection of oestrus, the ewes were mated naturally at 6 and 12 h, and some ewes were inseminated laparoscopically. Embryos were recovered surgically 5 or 6 days after service. All ewes exhibited oestrus. The onset of oestrus occurred significantly (P < 0.05) earlier in FGA-treated (50.0 ± 1.5 and 48.0 ± 0.00 h) than in cloprostenol-treated groups. There were no significant differences (P > 0.05) in the mean time of onset of oestrus (50.0 ± 1.5 and 48.0 ± 0.00 h) between the two doses of cloprostenol. The mean number of corpora lutea (8.1 ± 1.26) and embryos recovered (6.1 ± 1.00) was significantly (P < 0.05) higher in ewes treated with 45 mg FGA than in ewes treated with cloprostenol. Embryo recovery rate was significantly (P < 0.05) higher in ewes treated with 45 mg FGA (75.4%) than in other groups (41.7% and 51.6% in 100 μg and 175 μg cloprostenol- and 52.7% in 30 mg FGA-treated groups, respectively). Fertilisation rate was 93.3% in ewes given 100 µg cloprostenol, whereas other groups showed 100% fertilisation rate. The highest percentage (100%) of Grade 1 embryos was in FGA groups. In conclusion, despite FGA protocol presenting superior results, cloprostenol protocol was equally efficient in synchronising oestrus. The embryo recovery rate was better after 45 mg FGA than 30 mg FGA or after either dose of cloprostenol.