Effect of some hormonal and enzymatic supplements on reproductive and productive performance of Ossimi ewes

Two experiments were conducted to evaluate the effect of administrating melatonin, ZADO and their combination on reproductive performance of Ossimi ewes in the first experiment and ZADO supplementation effects on milk yield and lambs growth in the second experiment. Exp.I. fifty-seven, multiparous, adult Ossimi ewes were randomly assigned to four groups, each group fed ration supplemented with one of the following components: melatonin (G1; n = 14), ZADO (G2; n = 14), melatonin and ZADO (G3; n = 15) and ration with no additives (G4; n = 14). All ewes were fed maintenance ration for one month (during June) followed by flushing ration for five weeks (two weeks before and three weeks after ram introduction). Melatonin 3mg/h/d) and ZADO (15g/h/d) started to be added with maintenance and flushing rations, respectively. Fertile rams were introduced for two successive estrous cycles. Percentage of ewes expressed estrus was significantly different (P 0.05) among the treatment groups. All ewes expressed estrus in G 1, while the lowest percentage (71 %) was detected in G4. The interval from ram introduction to the onset of estrus differed (P 0.01) among treatment groups. Ewes received melatonin in G1 and G3 expressed estrus earlier than ewes didnt receive melatonin in G2 and G4. Neither body weight nor body condition score were different at the fIrst estrus following ram introduction, while average daily gain (ADG) was promoted by treatments particularly melatonin, but the difference was not significant. Lambed ewes as percentage of total ewes were similar in G3 and G4 (50%), while they increased in G1 and G2 (57 and 67% respectively). Prolificacy was greater in G1 and G3 than that in G2 and G4. Maximum prolificacy Was detected in G3 while the minimum was observed in G4, the difference Was significant (PO.OI). Fecundity Was lower (P 0.01) in G4 (control group) than all the treated groups Gl, G2 and G3). Results of the present stud indicated that melatonin could increase the estrus expression of ewes and decrease the interval to estrus after ram introduction. Exp.II twenty recently lambed Ossimi ewes were used with their offsprings in this experiment. Ewes were equally divided Into two groups (ten ewes in each). Group 1 Was supplIed with 10 g/head/daY ZADO mixed with total ration, while group 2 had the same ration with no additives and served as control. The average daily milk yield (DMY) Was 907 vs. 787 g and weaning weight was 17.46 vs. 15.20 kg for ZADO supplemented and control groups, respectively. Melatonin alone or in combination with ZADO could increase prolificacy. Treated ewes with melatonin and/or ZADO could improve fecundity. ZADO supplementation could improve DMYand Iamb weight at weaning.