Pre-breeding nutritional management of rams is critical to viable, sustainable, and profitable farms in the tropics. This study aimed to evaluate the effect of flushing with varying energy and protein levels on the reproductive characteristics and semen quality of Menz rams. Fortynine Menz breeding rams, with an average age of 18.79±3.9 (Mean + SD) months, were used. The rams were allowed to graze daily for 8 hrs on natural pasture and fallow lands. The study was conducted using a randomized complete block design. The treatments used were combinations of diets consisting of three energy levels above farmers’ practice (High (50%), Medium (40%), and Low (30%)) 9.91, 8.14, 7.02 MJ ME/kg DM, respectively) and two protein levels (high and low; (12.5% and 8.17%), respectively). The Farmers’ practice was grazing on natural pasture (energy and protein 4.7 MJ ME/kg DM and 6.65%, respectively) was used as a control. Semen was collected early in the morning (7:30 - 8:30 am) from each experimental ram every seven days by using an artificial vagina. Physical parameters such as semen volume, sperm concentration, sperm motility, color, viscosity, sperm morphology were determined in fresh semen. In addition to these body condition score, body weight, scrotal circumference, libido, and predictive potential of rams to serve ewe were collected during the experimental period. Body condition score, scrotal circumference, semen volume, spermatozoa concentration, and prediction potential of rams to serve ewe were greater (P<0.05) in the supplemented groups than in the control. There was no significant difference (P>0.05) in all variables within supplemented groups. Moreover, libido, the color of semen, semen viscosity, and sperm morphology were not significantly (P > 0.05) different between the control and supplemented groups. The body condition of rams was positively correlated with scrotum circumference (r=0.57), semen volume (r=0.54) and the potential of rams to serve ewe (r=0.44). The scrotal circumference was positively correlated with volume (r=0.89), prediction potential of ram to serve ewe(r=04). Energy and protein supplementation above farmers’ practice to Menz rams during the breeding season improve reproductive performance and semen qualities. Based on the cost of supplementary feed T6 and T3 were recommended to improve the reproductive performance, semen quality and potential of rams to serve ewes of breeding Menz rams. Since the study was conducted in one season (spring, harvest time) and the semen quality of rams is influenced by season, the similar feeding situation in different seasons of the year should be evaluated.