Acta Vet. Brno 2022, 91: 243-250

Effect of oestrus synchronization with different lengths of progesterone-impregnated sponges and equine chorionic gonadotropin on reproductive efficiency in Romanov ewes during the non-breeding season

Mushap Kuru1, Buket Boga Kuru2, Cihan Kacar1, Murat Can Demir1, Nebi Cetin3

1Department of Obstetrics and Gynaecology, Faculty of Veterinary Medicine, Kafkas University, Kars, Turkey
2Department of Animal Breeding and Husbandry, Faculty of Veterinary Medicine, Kafkas University, Kars, Turkey
3Department of Obstetrics and Gynaecology, Faculty of Veterinary Medicine, Van Yüzüncü Yıl University, Van, Turkey

Received September 23, 2021
Accepted June 14, 2022

This study aimed to determine the effects of different lengths of progesterone and equine chorionic gonadotropin (eCG) treatment on reproductive performance during the non-breeding season in ewes. Progesterone-impregnated sponges were inserted intravaginally for 7 d in Group 1 (G1, n = 24), 9 d in Group 2 (G2, n = 25), and 11 d in Group 3 (G3, n = 24). On the day of sponge removal, eCG (350 IU) was injected and 24 h later the ewes were exposed to rams. Pregnancy was diagnosed by transrectal ultrasonography 30 ± 3 d after mating. Oestrus symptoms of G2 and G3 started earlier than G1, but there was only a significant difference between G1 and G3 (P = 0.013). In G1, G2, and G3, the oestrus responses were 100%, 100%, and 95.8%, pregnancy rates were 79.2%, 72%, and 75%, lambing rates were 79.8%, 72%, and 75%, litter sizes were 2.5, 2.2, and 2.4, and multiple birth rates were 86.7%, 80%, and 85.7%, respectively (P > 0.05). In conclusion, the short-term progesterone-impregnated sponge and eCG treatment provided excellent oestrus induction. The effects of different days (7, 9, or 11) of progesterone treatment on reproductive indicators were similar; therefore, the stress caused by the inserted sponge can be reduced by short-term use.


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