Comparison of Progestagen Sponges and Progesterone CIDRs Short-Term Treatments in Terms of Estrous Synchronization and Reproductive Performance during the Non-Breeding Season of Sanjabi Ewes

Document Type : Original Article

Authors

Department of Clinical Science, Theriogenology Section, School of Veterinary Medicine, Razi University, Kermanshah, 6715685414, Iran.

Abstract

A more precise understanding of the commencement of behavioral estrus and pre ovulatory luteinizing hormone (LH) peak and the progesterone (P4) hormonal profile in sheep treated with either FGA‐impregnated sponges or progestagen‐loaded CIDR in short‐term protocols would increase conception rate of fixed timed artificial insemination (FTAI). The present study aim was to investigate the efficiency of different treatments of progestogen with eCG in Sanjabi breed ewes out of breeding season. Fifty Sanjabi ewes were divided equally into sponge (SP) and CIDR groups. At the moment of CIDR or sponge removal (Day 6), the animals were injected with 400IU eCG. Estrous characteristics and reproductive performance were measured in each of the treated groups. The P4 concentration and the characteristics of LH surge were determined. There were no significant differences among the groups CIDR and SP for estrous response, onset, and duration, P4 concentration at device removal, on estrous day, on the 11th and 30th days after device removal, LH surge onset and concentration. Also, there were no significant differences in the conception, lambing, fertility, prolificacy and twining rates in ewes synchronized with either SP or CIDR. The results of this study showed that short‐term (6-days) protocols with FGA and/or CIDRs are equally effective for estrous induction and synchronization and no differences between the two treatments were apparent regarding estrus response, P4 and LH profiles, ovulation, fertility and reproductive performance. Thus, short-term progestagen treatment can be recommended as an alternative to traditional treatment (12-14 days).

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