REPRODUCTIVE PERFORMANCE OF BARKI EWES IN SIWA OASIS AS AFFECTED BY INCLUDING DATE SEEDS IN THE CONCENTRATE RATION
The present study investigated the effect of feeding date seeds on productive efficiency of Barki ewes in Siwa Oasis. 75 adult Barki ewes (37.8 ± 0.63 kg) were divided into three equal groups; (G1) was kept as control (0.0% date seed), while the other two groups were fed on date seeds as a partial (50%, G2) or complete replacement (100%, G3) of the yellow corn in the concentrate diet. Animals were offered berseem (Trifolium alexandrinum)hay ad libitum and had access to fresh water twice a day. Estrus cyclicity and hormonal profiles during estrous cycle and pregnancy were determined. Reproductive parameters (no. of services/conception, conception rate, lambing rate, average litter size and mortality rate) were also recorded.
Results indicated that date seeds contain estrogen-like compounds (β -sitosterol, stigmasterol and estradiol) with values of 0.01, 0.31 and 0.10 mg/kg, respectively. These levels did not affect estrus activity, since 90 and 80% of the ewes exhibited regular estrous cycle lengths with an overall mean of 17.3 ± 1.09 and 17.1 ± 0.86 days, respectively.
Estradiol-17β (E2) and progesterone (P4) profiles either during estrous cycle or pregnancy were found to follow the normal pattern reported in the literature. Plasma (P4) levels increased during pregnancy, especially during late pregnancy and decreased to the basal values during lactation, while plasma (E2) levels were not significantly different among experimental groups.
Date seeds, on the other hand, had improved all reproductive parameters studied as compared to the control group. Conception rate and lambing rate were found to be higher in both G2 (92 and 92%) and G3 (88 and 80%) as compared to the control group (76 and 72%), respectively. No abortions or stillbirths were found in the three groups.
These results may confirm that date seeds have no estrogenic effects, and could be used safely as a partial (50%) or complete replacer (100%) for the concentrate ration of ruminants, which in turn positively reflect on the Bedouins income and animal health under desert conditions.
Keywords: Date seeds, Barki ewes, Estrus activity