This study was carried out at Sakha Experimental Farm during the period from Dec., 2005 to April, 2007 to evaluate the monthly, seasonal and breed variations in physical semen characteristics of 10 Zaraibi (17-42 kg LBW), 10 Damascus (40-72 kg LBW) and 10 Alpin bucks (27-55 kg LBW). All animals ranged between 24-48 months in age. All bucks were kept under tha same environmental conditions. Semen was collected once weekly durind all months of the year by an artificial vagina between 8.0 and 9.0 a.m. Physical semen characteristics including ejaculate volume (EV), sperm cell concentration (SCC), percentages of mass motility (MM), live (LS) and abnormal (AS) sperm, and total sperm output (TSOP) of bucks of different breeds were evaluated in fresh semen. Results revealed that EV was the highest (P<0.05) in Alpin, followed by Damascus, and the lowest in Zaraibi (0.72, 0.67 and 0.56 ml, respectively). Percentage of MM was higher (P<0.05) in Zaraibi (80.8%) than in Alpin (77.5%) and Damascus (77.1%). Percentage of LS was higher (P<0.05) in Zaraibi (81.2%) than in Alpin (77.3%) and Damascus (75.8%). Percentage of AS was higher (P<0.05) in Damascus (7.9%) and Zaraibi (7.8%) than in Alpin (7.6%). SCC/ml was the greatest (P<0.05) in Zaraibi (2.94 x109) than in Alpin (2.44 x109) and the least in Damascus (2.28 x109). TSOP/ejaculate was higher (P<0.05) in Zaraib and Alpin than in Damascus semen by about 17.5%. As affected by monthly change, EV of Damascus and Alpin increased (P<0.05) to 0.94 and 0.91 ml in October and 0.91 and 0.84 ml in November, respectively, and increased to 0.77 and 0.73 ml in October and November for Zaraibi, respectively. The minimal EV was in April for all breeds. The highest MM percentages in all breeds were in July and August, while the minimal values were in April. The highest LS percentages were in July (81.3%) for Damascus, in September (82.6%) for Alpin and in October (85.7%) for Zaraibi. In all breeds, AS percentage was the lowest in October and the highest in April. The greatest SCC/ml was in August for Zaraibi (2.6 x109/ml), in November for Damascus (1.73 x109/ml) and in January for Alpin (1.97 x109/ml).
TSOP/ejaculate was the highest in October for Damascus and Alpin (1.76 and 2.06 x109), respectively, and in November for Zaraibi (1.94 x109). The least TSOP/ejaculate was in April for all breeds. EV was the highest in autumn than in summer (0.72 vs. 0.79 ml) and in winter than in spring (0.48 vs. 0.65 ml). Percentage of MM was the highest (81.3%) in summer, moderate in autumn (79.7%) and the lowest in winter and spring (76.9 and 76.1%), respectively. Percentage of LS was the highest (P<0.05) in autumn and summer than in winter and spring (74.2 and 74.9% vs. 82.1 and 81.4%, respectively). Percentage of AS was the highest (P<0.05) in spring (9.7%), moderate in winter and summer (8.2 and 7.9%, respectively), and the lowest in autumn (5.4%). SCC/ml was the highest (P<0.05) in spring (2.81 x109), moderate in summer (2.58 x109), and the lowest in autumn and winter (2.42 and 2.41 x109, respectively). TSOP/ejaculate was the greatest (P<0.05) in summer and autumn (1.78 x109 for each), moderate in winter (1.48 x109), and the least in spring (1.34 x109).