Abstract
Methods of the semen collection may be a factor influencing the activity of the egg-yolk coagulating enzyme in goat semen. In this experiment, enzyme activity of the semen collected by the electrical stimulation (E. S.) was compared with the activity of the semen collected by the artificial vagina (A. V.). And the other experiment was carried out to examine the changes in the enzyme activity of the semen collected by the artificial vagina 7 to 8 times successively in about an hour until most of the sperm was depleted.
The general properties and some seminal constituents such as fructose, citric acid and protein were examined in both experiments mentioned above.
These two experiments were carried out using three male Saanen goats in the breeding season of 1960 to 1962.
Principal results obtained are as follows.
A. General properties and the enzyme activity of the ejaculate collected by E. S. The data from 25 sperm free ejaculates obtained by E. S. and the one from 18 semen samples collected by A. V. were compared.
1. The pH value of the E. S. ejaculates, 7.9+0.6 was markedly higher than that of the A. V. semen, 6.3+0.1.
2. Concentrations of fructose, citric acid and protein in the seminal plasma of the E.S. ejaculate were 1.8±1.0g/dl, 170.6±145.7mg/dl, 246.1±166.0mg/dl respectively, and these were markedly lower than those of the A. V. semen, 7.1±1.1 mg/ dl, 1242.7±16.0 mg/dl, 794.6±153.3 mg/dl.
3. Enzyme activity ofthe seminal plasma of the E. S. ejaculate and of the A. V. semen was 41.6±10.0 mg/0.1 ml, 29.5±4.3 mg/0.1 ml respectively. Specific activity of the enzyme (activity per mg of protein) of the E. S. ejaculate was about 6 timeshigher than that of the A.V. semen.
4. It was found from the results of thepaperelectrophoretic studies that the seminal plasma protein which has a higher specific activity showed lower mobility.
These results mentioned above suggest that the sperm free fractions collected by E.S. contained seminal vesicle constituents only in small amounts but much of the Cowper's gland secretion which may be rich in the enzyme.
B. General properties and the enzyme activity ofthe semen collected 7-8 times successively in about an hour.
1. Comparing the 1st collection with the 7-8 th collection, it is found that semen volume was reduced from 0.91 ml to 0.31 ml, and the sperm density was decreased from 34.8x108/m/lto 6.2x108 /ml.
2. Concentrations of the seminalfructose, citric acid and protein that may be secreted from the seminal vesicle were not markedly decreased in a degree of depleted condition of this ex-periment. Fructose concentration tended to increase slightly up to the 3rd collection.
3. Activity of the egg-yolk coagulating enzyme secreted from the Cowper's gland was 11.60 mg/ 0.1 ml in the 1 st collection, and was markedly increased up to the 5 th collection, the increased activity, 51.43 mg/0.1 ml, being maintained up to the 8th collection.
From the above results it was suggested that the secretory functions of the seminal vesicle and of the Cowper's gland may be considerably different.
