Using Progesterone and Prostaglandin F2α for Ewes Estrus Synchronization during Summer Season in Egypt

Abstract

This study was carried out to investigate the effect of administration of progesterone (P4) and prostaglandin F 2α (PGF 2α) hormones on ewe estrus synchronization during summer season in Egypt. The study was performed on thirty four non-pregnant or lactating local ewes, 2-4 years old and 42.1 ± 1.8 kg average live body weight. Ewes were randomly divided into three groups as follows: natural estrus (control n = 10), intervaginal progesterone sponges (P4 = 12 ewes) for 12 days and two injections of PGF 2α (12 ewes) 12 days apart. Parameters of estrus, conception and body weight of lambs were measured. Results showed that the percentage of estrus signs exhibition in PGF 2α group reached 83.3%, while the lowest percentage (60%) was observed in control group (P<0.05). The time of starting estrus was earlier (P<0.05) in PGF 2α and P4 groups (44.8 and 46h, respectively) than that in control group (58.4 h). The estrus duration was significantly longer (P<0.05) in PGF 2α and P4 groups (44 and 41.6 h, respectively) than control group (31.2 h). The percentages of pregnant and lambing rates were 100% in all animals came to heat in all groups. While pregnancy rates and lambing rates according to initial number used were 83.3, 75% and 60% for PGF 2α , P4 and control groups (P<0.05), respectively. The litter size, birth weight and weaning weight of lambs born did not differ significantly among groups. Weaning rate was the highest (P<0.05) in PGF 2α group (92.9%) and the lowest in P4 group (85.7%). The percentage of ewes lambed twins was the highest (P<0.05) in P4 group (56%) and the lowest percentage in control group (33%). The percentage of male lambs was the highest (P<0.05) for ewes in PGF 2α group (57.1%) and the lowest for ewes in control group (37.5%). In conclusion, PGF 2α and P4 protocols could adequately induce estrus synchronization and improve some reproductive and productive traits in local ewes during summer season in Egypt. Further studies are recommended to proof results using more number of ewes.

The Role of Certain Specific Hormonal Treatments in Estrus Synchronization of Ewes: A mini Review

“…This phase can be performed by prolonging the presence of progesterone in the blood serum using progesterone. Its derivatives and estrus are controlled and induced in females using techniques that artificially control the balance of hormones through external hormones or other methods that lead to a change in the hormonal balance of the ewe [42]. The technique of estrus synchronization has many benefits; it unifies the time of feeding and childbirth and thus reduces the efforts and expenses spent on caring for newborns, and is useful in raising productive efficiency by obtaining additional births during productive life and is also useful in embryo transfer programs, and determining the date of pregnancy and childbirth, and then facilitates the process of feeding animals in homogeneous groups [43].…”