بررسي بلوغ جنسي و تعيين مطلوبترين وزن و سن جهت توليد اسپرم نرمال در بره هاي نر مهربان

The effect of sexual maturity, suitable age and body weight on normal spermato ozoid production in Mehraban male lamb

Twenty-five lambs were studied from birth to stage of normal spermatozoid production. These Iambsʹs testis were operated: Two lambs in every month until 120 days of age and three lambs in every 15 days until 180 days of age. Body weight and testis length, width, weigh and volume were recorded until the time of spermatozoid production. Tissue section and epididymis liquid of operated testis were prepared for microscopic study and determination of semen quality. Semen quality and quantity were examined in six Iambs after they produced normal spermatozoid. Normal spermatozoid production was observed by the results of microscopic study and epididymis liquid survey in 165 days old male lambs. This reaction was associated with dramatic increase of body weight, testis weight and volume. The means of these characteristics (body weight, testis weight and volume) were 30kg, 157.57g and 175.33Cmʹ at this age, respectively. Density and activity of spermatozoid were increased after this age (165 days old lambs). Following of this study, the Iambs were tested for quantity and quality of semen and sexual behavior until 18 months of age. They did not show any clear sexual trend and collection of semen was impossible by artificial vagina in this period. Sexual trend and semen production were normal after this age (18 months). In this suitable situation 2.4 billion spermatozoids per ml of semen were found in 58 kg of body weight. The result of this study have shown that high sexual capacity and normal spermatozoid production were associated with 58 kg of body weight and 18 months of age in Mehraban male lambs.