The effects of short-mid-long term intravaginal sponge application on reproductive performance of karacabey Merino ewes in the anestrous season

Abstract

The aim of the present paper was to investigate the efficiency of different progestagen treatment methods in combination with Pregnant Mare Serum Gonadotrophin (PMSG) in Merino ewes outside the breeding season. A total of 78 ewes (2 to 4 years old) with a mean bodyweight of 58.4 kg and an average body condition score (BCS) of 3.5 were used in the trial. The ewes were randomly divided into 3 equal groups [n= 26]. Intravaginal progestagen sponges containing Fluorogestone Acetate (FGA; 30 mg) were inserted intravaginally for different periods (7_days: short-term; 10_days: mid-term, 14_days: long-term). In all cases, 500 IU PMSG was administered intramuscularly at sponge withdrawal. The oestrus response, lambing rate, multiple birth rate, fecundity and litter size were [65.4, 61.5, 18.8 %, 0.77 and 1.25] in the short-term group; 80.8, 88.5, 34.8 %, 1.31 and 1.48 in the mid-term group; and 96.2, 92.3, 62.5 %, 1.50 and 1.63 in the long-term group, respectively. Oestrus manifestation and multiple birth rate were greater in long-term than in mid-and short-term groups, whereas for lambing rate, fecundity and litter size, better results were obtained in long-and mid-term than in short-term protocol. In conclusion, in Merino ewes, oestrus synchronisation outside the breeding season with long and mid-term progestagen treatment was found to be more effective than short-term treatment.

Comparison of Five Protocols of Estrous Synchronization on Reproductive Performance of Hu Sheep

“…The percentage of estrous ewes treated with progestogen sponge for a long term (14 days) was significantly higher than that of ewes treated for 7 and 10 days ( P < 0.05) ( 17 ). In this study, there was no significant difference in the total percentage of estrous ewes treated with different protocols of estrus synchronization, and there was no significant difference in the proportion of estrous ewes in any one of the five time periods within 72 h after withdrawal of the sponge among five protocols.…”

“…It was reported that the lambing rate of ewes treated with FGA (30 mg) for 14 days was significantly higher than that of ewes treated for 7 days ( P < 0.05) ( 17 ), indicating that the long period treatment of the FGA intravaginal sponge was conducive to lambing rate of ewes. It is worth noting that the breeders usually wish the twinning lamb because compared with multi-lamb, twinning lamb has larger birth weight, easier survival, and better growth ( 36 ), which is especially conducive to the breeding and management of large-scale sheep farms.…”

“…Another research has shown that the estrus of ewes with the FGA sponge for 14 days was earlier than that of ewes using the FGA sponge for 6 or 7 days ( P < 0.01) ( 16 ). Altineki and Koyuncu ( 17 ) studied the effect of FGA vaginal sponge on estrus and lambing of Merino ewes and concluded that the effect of medium-term (10 days) and long-term (14 days) treatments was better than that of short-term treatment (7 days).…”

Development and evaluation of an injectable slow‐release progesterone formulation for estrus synchronization in ewes out of the breeding season

“…Different rates of estrus induction and pregnancy have been reported in various studies using CIDRs and sponges. Altinçekiç and Koyuncu (2019) used FGA sponges (30 mg) and 500 IU eCG at sponge withdrawal for estrus induction in Merino ewes during the anestrus season for different periods (7, 10, and 14 days). They observed estrus behaviour in 65.4, 80.8 and 96.2 percent of treated ewes in short, mid and long‐term groups.…”

“…They observed estrus behaviour in 65.4, 80.8 and 96.2 percent of treated ewes in short, mid and long‐term groups. Also, the lambing rate was 61.5, 88.5 and 92.3 percent respectively (Altinçekiç & Koyuncu, 2019). Likewise, Swelum et al (2015) compared CIDR and FGA sponges (30 mg) in estrous synchronization and hormonal profiles of Najdi ewes during the breeding season.…”