Age of sexual maturity in Holstein bulls. Change in the semen characteristics of bulls from 5 to 17 months of age

概要

論文の詳細を見る
1. Morphological and Chemical analysis was made in semen of six Holstein bulls from 5 to 17 months of age, to determine the age of sexual maturity. Semen was collected once a week by the electrical ejaculation and evaluated on the following characteristics : volume, pH, concentration of spermatozoa, sperm count per ejaculate, initial motility and percentage of live spermatozoa. In addition, the concentration of fructose, total nitrogen, ascorbic acid, acid-soluble phosphorus, calcium, sodium, potassium and chlorine in semen were estimated. 2. Puberty in the bulls as shown by the appearance of motile spermatozoa in semen, was in average 8. 5 months of age. The volume of semen was less than 2.5ml before 12 months of age. At 13 months, mature values were recognized in the sperm count per ml and per ejaculation, as 4×108 and 10×108, respectively. Sperm motility showed 50 in the index of motile sperm at 11 months. pH showed above 8.0 before 6 months, then gradually decreased to below 6.8 after 10 months of age. 3. Seminal fructose did not appear until bulls reached 5.3 months of age in average. At 9 months, more than 500 mg of fructose and total nitrogen, and 19.5 mg of calcium were evaluated in the 100ml semen. 35 mg of acid-soluble phosphorus and 6.5 mg of ascorbic acid were evaluated in the 100ml semen at 13 and 14 months of age, respectively. Chlorine was more than 400 mg in 100ml before 8 months of age, thereafter it decreased to less than 270 mg at 11 months. Sodium and potassium in semen showed an almost constant value throughout the experimental period. 4.These results shows that the age of sexual maturity in Holstein bulls is 13 or 14 months.
日本繁殖生物学会の論文

Age of sexual maturity in Holstein bulls. Change in the semen characteristics of bulls from 5 to 17 months of age

スポンサーリンク

概要

日本繁殖生物学会 | 論文

スポンサーリンク