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

Document Type : Original Article

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Abstract

This study was carried out to investigate the effect of administration of progesterone (P4) and prostaglandin F(PGF) 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(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 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 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 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, 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 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 group (57.1%) and the lowest for ewes in control group (37.5%). In conclusion, PGF 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.

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