Effect of sexual rest on non-return ratio and rams testosterone levels were studied in this experiment. A
group of female sheep was divided into four groups according to period of ram sexual rest, in which there were period
of 1, 3, 5 or 7 days of sexual rest provided to rams prior to mating time. Results showed that the optimal sexual rest for
rams was 3 days before mating and this period was correlated with testosterone level of used rams. Where testosterone
levels for three used rams were 2.7, 2.48 and 2.25 ng / ml and correlated conception rate % were 60, 38.5 and zero for
the used rams.