ABSTRACT
The current study was carried out to investigate the effect of treating rice straw bales by
enzymes (ZAD) or by effective microorganisms (EM) on sexual activity and reproductive
performance of Ossimi sheep. Trial I, twenty-four lambs (12 males and 12 females) were randomly
divided into three groups, first group fed control ration [concentrate feed mixture (CFM) and rice
straw (RS)], and second group fed CFM and RS treated with ZAD). The third group fed on CFM
and RS treated with EM. Body weight, age, T3, T4 and testosterone were determined at puberty,
quality and quantity of semen collected from ram lambs and mature rams were also assessed. The
fertility test assayed with mature rams and ewes. Results showed that age, body weight (BW), total
gain and average daily gain values at puberty of both ram and ewe lambs were increased (P<0.01)
in treated groups compared to control. Both ram and ewe lambs fed ZAD or EM reached puberty
faster and levels of testosterone and thyroid hormones (T3 and T4) developed earlier than those of
the control lambs. Moreover, ram lambs and mature rams in ZAD or EM groups were better in
sexual activity and produced higher semen quality (P<0.01) than those of the control group.
Trial II, one hundred and fifty adult Ossimi ewes and three adult Ossimi rams without
significant differences in semen characteristics were used in this trial. Rams given the previous
three treatments. Ewes divided into three groups; first group (90 ewes) wasn't treated pre-mating
(control), they fed control ration; and divided into three equal subgroups: A (n =30) mated by ram1
which not treated, B (n =30) mated by ram2 which treated by ZAD and C (n =30) mated by ram3
which treated by EM. Second group (30 ewes) treated by ZAD pre-mating and the third group (30
ewes) treated by EM pre-mating, and these two (2nd & 3rd) groups were mated by ram1 which not
treated. Results showed that reproductive performance (reproductive ability, estrus duration,
fertility rate, pregnancy rate, gestation period, lambing rate, fecundity rate, still birth and twining
rate) of treated sheep fed ZAD or EM were higher than those fed control ration. It could be
concluded that enzymatic or microbial treatment to rice straw can improve reproductive
performance of sheep.