Productive Characteristics and Reproductive Responses to Estrus Synchronization and Flushing in Abou-Delik Ewes Grazing in Arid Rangelands in Halaieb - Shalateen - Abouramad Triangle of Egypt.

Abstract

There are a few reports about the reproductive aspects or uses of both of flushing and estrus synchronization in Abou-Delik ewes grazing in the South Eastern zone of Egypt. Thirty-three Abou-Delik ewes were allocated to three experimental groups (n = 11 in each) to study the effects of estrus synchronization and flushing on reproductive responses and productive characteristics under arid conditions of South Eastern zone of Egypt. Group one served as control represent the system dominant in the area (without estrus synchronization and flushing ration). Ewes in group two were estrous synchronized with two doses of PGF 2 α, 10 days apart without flushing ration. Ewes in group three were estrous synchronized just like the second group and received 300g of barley grain/head/day as flushing meal for three weeks before the start of breeding season. All ewes were grazed Panicum turgidum (natural vegetation dominant in the area) for eight hours daily. Results showed that, the percentage of estrus exhibition in group three reached 100%, while the lowest percentage was observed in group one (81.82 %). Estrus activity signs in synchronized groups, occurred in 70 and 81.81% during the first 48 h after the second dose of PGF 2 α, for groups two and three respectively, compared to control group (22.22 %). The onset of estrus was earlier in synchronized groups than control group. Duration of estrus did not differ significantly. Estrus intensity in group three was higher (P<0.05) compared to the other groups. Conception and lambing rates were 100% in group three. Third group showed the highest insignificant litter size that was 18% higher than the other groups. The overall mean of birth weight, weaning weight and average daily gain of Abou-Delik lambs were 2.91, 16.89 and 0.116 kg, respectively. There is no significantly effect on concentrations of plasma progesterone among groups. While there were significant differences between sampling periods. In conclusion, under grazing on arid rangelands conditions in the South Eastern zone of Egypt, using flushing and/or estrus synchronization can be useful to improve reproductive and productive characteristics of Abou-Delik sheep.received flushing ration (300g of barley grain/ head/ day) three weeks before introducing rams. Estrus was synchronized with two PGF 2 α, 1 ml intramuscularly injections given 10 days apart. Estrus detection and matingDuring the mating season (July, 2017), ewes were presented to three fertile Abou-Delik rams (1 ram / 11 ewes) and natural mating was allowed. The duration of the mating period was 17 days (equal to one estrus cycle length) in the control group. Synchronized groups (2 and 3) had four days (= 96 h) for mating after second PGF 2 α injection. Paintedbreast fertile rams were introduced to ewes and left with them for estrus detection and natural mating. Rams were allowed to rotate among ewes in different groups (to avoid mixing effect for rams within groups).Estrus detection was checked through the observation of the paint marks on the ewe's rumps. Ewes ...

Effect of seasonal variations during dry and wet seasons on reproductive performance and biological and economic criteria of hair sheep under Halaieb rangeland conditions

“…Feeding ewes at a level below maintenance results in loss of live weight (LW) and body condition score (BCS) and, during mating, severely reduces lambing percentage (McWilliam et al, 2005). The present results of prolificacy agreed with those reported by Farrag (2019), where prolificacy in Abou-Delik sheep increased as a consequence of increasing feed provided to ewes. Grazing sheep in the Halaieb triangle, like other Egyptian sheep, are characterized by pretty good fertility rates, an extended breeding season, but low prolificacy (Gabr et al, 2016), thus not significantly influenced by seasonality (i.e., ewes cycle all year round), which occurs due to slight variations in day length throughout the year.…”

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

“…Moreover, Zarkawi (2000) reported that the treatment had no effect on the duration of pregnancy, which averaged 150.3 days in control and 150.4 and 150.8 days in synchronized groups with 10 and 15 mg PGF2α, respectively. Whereas, pregnancy period in the present study was lower than that reported by Farrag (2019) who found that the average gestation length period were 157.37 and 154.88 days for control ewes and PGF 2α ewes, respectively in Abou-Delik ewes grazing in the South Eastern zone of Egypt. Also, Safranski et al (1992) who found that pregnancy periods in control ewes and ewes treated with melengesterol acetate (MGA) + PG-600 were 163.8 and 157.2 days, respectively in Kalkuhi ewes in Iran.…”

A Comparative Study on the Reproductive Performance of South African Indigenous Sheep Breeds Following Oestrus Synchronization

“…Results found between Bapedi sheep and Zulu sheep were similar to that reported previously by Kridli et al (2009); Zeleke et al (2005) and Mansur et al (2018) where lambing rate could not differ among breeds and their lactation statuses. The conception and lambing rate of Zulu sheep and Bapedi sheep were comparable to Farrag (2019) results who reported that, oestrus synchronization result in higher conception rate on the Abou-Delik sheep.…”