Abstract
The goal of this study was to evaluate and compare the semen characteristics, and testosterone concentration for three breeds raised under hot, desert conditions in Saudi Arabia. A total of 150 rams (Najdi, Naemi, and Harri) were used, aged 12, 18, 24, 30 and 36 months (ten rams from each breed in each age group). Body weight and testicular parameters were measured. In addition, testosterone concentration (TC), ejaculate volume (EV), sperm concentration (SC), total sperm output per ejaculate (TSO), live sperm percentage (LSP), sperm progressive motility (SPM) and sperm mass motility (SMM). The results show that TC and EV differed significantly (P < 0.01) between breeds. At 36 months, semen characteristics (TSO, SMM and SPM) differed significantly among breeds. Naemi rams were superior to Najdi and Harri in terms of the mean live sperm percentage (LSP) for all age groups. These results may assist in ram selection for breeding programs based on high reproductive performance.