الفهرس 
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Abstract
The objective of the present study was to evaluate the influence of hormonal and non-hormonal treatments on reproductive efficiency of Ossimi ewes.
Reproductive and productive measurements calculated in the study were:
Lambing rate (%) = (No. of ewes lambed / No of ewes mated) x 100.
Litter size (prolificacy) = (No . of lambs born / No of ewes lambed) x 100
Fecundity rate = lambs born / ewes mated.
Livability: (No . of lambs that remained alive / No . of lambs born).
Weaned rate (%) = (No . of lambs weaned / No . of lambs born) x 100.
Overall Reproductive Rate (ORR) = No . of lambs weaned / No. of ewes mated.
Net Reproductive Rate (NRR) = Total weight of lambs weaned / ewes mated.
KLBEL: (Kilograms of lambs born / No . of lambs born) and
KLWEL: (Kilograms of lambs weaned / No . of lambs weaned).
Exp. 1 : Thirty Ossimi ewes of 39.56 ± 0.72 kg average live body weight were used. Animals randomly divided into three groups. The first group (G1) (Flushing without hormonal treatment), the second group (G2) (flushing with injection of GnRH). While, ewes of the third group (G3) flushing and one injection of PGF2 + GnRH.
Animals were fed on concentrate feed mixture to cover their nutrient requirements according to live body weight (NRC, 2007). The basal flushing applied by feeding a gradual increased concentrate pelleted mixture, 14% crude protein, started by 500 g/h/day up to 1 kg/h/d during two weeks started prior breeding and two weeks through the breeding season beside added amount of rice straw. The experiment designed according to the complete randomized design (CRD). There was a significant effect (P>0.05 or P>0.01) due to the treatments on litter size at birth (LZB), fecundity rate (FR), net reproductive rate (NRR), birth weight (BW0), body weight at 10 wks (BW10), total daily gain from birth to 70 d. On the other hand, no significant differences were found due to treatments on laming rate (LR), litter size at weaning (LZW), overall reproductive rate (ORR), livability, body weight at 8 wks (BW8), and kilograms of lambs born (KLBEL) and weaned (KLWEL).
.EXP. 2: The experiment was performed on thirty three Ossimi ewes of 41.59 ± 1.05 kg average live body weight. Animals were randomly divided into four groups.G1-flushing (F) , G2- salt free- salt diet (SFSD), salt- free diet is implemented for 7-day period, followed by salt-containing one for another 7 days with 10 g salt per ewe per day+ F, G3-Multi Vitamins (The scheme of two fold injecting of multi vitamins every 7 days at the dose of 5 см³ to the ewes and 10 см³ to the rams) + F, and G4- received one injection of GnRH (1 ml Receptal) + F. All ewes and rams were fed 500g/ head/day concentrate pelleted mixture 14% crude protein increased gradually to one kg in flushing period (two weeks prior to breeding and continued two weeks until the breeding season) and rice straw were provided. The experiment was designed according to the complete randomized design (CRD).
The obtained results showed that there was a significant effect (P>0.05 or P>0.01) due to treatments on litter size at birth , litter size at weaning (at 8 wks) and total daily gain (from birth to weaning). The best results obtained for the previous traits were 1.66 , 1.46 and 0.134 kg followed by 1.25, 1.25 and 0.130 kg for the flushing only and GnRH Hormone + F treatments While , the lowest values were 1.0, 1.0 and 0.120 kg and 1.0, 1.0 and 0.118 kg for G2 and G3, respectively. On the other hand, there were no statistically significant differences in lambing rate, birth and weaning weights, Kilograms of lambs born and weaned traits. It could conclude that use of normal diet (as flushing) succeed to improve fertility, without need to the tested treatments. Particularly when considering the treatments cost added.
. The less fertility of hormonal treated groups compared to control group in this study may due to that increasing GnRH level exert agonist inhibitory effects or blocked GnRH receptors by chemical antagonists for GnRH or that the condition of ovaries at time of receiving the hormone leads to differences in the response of ewes when start the oestrus cycle. Besides, it is better to repeat the experiment using a larger number of ewes and in different seasons to confirm these results. Also, the application of flushing only or flushing plus hormone GnRH injection resulted in improved fertility in ewes, while there was no significant effect of the addition of vitamins or minerals plus flushing in this regard. Still the few number of animals used in scientific research in developing countries remains a problem because sample size plays an important role in the results. Therefore, it is preferable to repeat the experiment using a larger number of ewes and in different seasons to confirm these results.