Semen characteristics of two breeds of turkey

Summary. Semen samples were collected from ten Bronze and ten Beltsville Small White turkeys by the massage method without milking the copulatory organ. The birds were kept under natural conditions at Giza, Egypt (lat. 30\s=deg\N).Four collections were tested each month throughout 1 year. The collections of alternate weeks were used for studying the physical and chemical characteristics respectively. The largest volumes of semen were produced between March and October, and the smallest between November and February. The best semen quality was recorded between November and April, and the poorest between May and August. A sharp decline in all semen characteristics occurred during May. If the causes of this decline can be avoided, the time of obtaining best semen qualities is prolonged. The semen pro-duction of Beltsville Small White turkeys was better than that of the Bronze breed. Wide seasonal variations in types of sperm abnormality were observed. Seminal fructose and vitamin C were high between November and April, and low from May to August. Semen quality was directly related to levels of seminal fructose and vitamin C. Slight seasonal and monthly variations were observed in inorganic phosphate levels. The rate of fructose metabolism by the spermatozoa was high during the first hour and decreased consistently thereafter. The large quantity of carbon dioxide produced during the first hour depressed sperm viability