Abstract
On the chemical composition of goat semen only a few reports have been issued. In the present experiment the chemical constituents of the goat semen collected from each of three goats during 12 to 24 months were examined. And five goats were killed for determining the chemical composition of the secretions of their accessory sexual organs. On the other hand, it has already been known that the egg-yolk coagulating enzyme exists in the goat semen characteristically, so we also intended to examine the presence of constituents that characterizes the goat semen in comparison with the semen of other farm animals. Principal results obtained are as follows.
1. The pH value of the ejaculated goat semen was 6.5 on the average (Brom Thymol Blue test paper method). Semen volume and sperm density were 0.63 ml and 37.5 x 108/ml on the average respectively. Semen volume was larger in the breeding season than in the non-breeding season, while sperm density was higher in the non-breeding season.
2. Concentration of total nitrogen in the seminal plasma of ejaculated goat semen was about the same as in bull or ram semen, and non-protein nitrogen was about 4 times as much as in bull and ram semen and 10 times as much as in boar semen. Concentrations of fructose and citric acid in the seminal plasma were 707.7 mg /d/ and 384.0 mg/dl respectively, and the amounts of these constituents were extremely larger in the breeding season than in the non-breeding season.
3. Phosphrous compounds were analized on each of fractions fractionated by SCHNEIDER'S method. A large amount of acid-soluble phosphorus were detected in the seminal plasma and the level of nucleic acid phosphorus was high in the sperm. Concentrations of potassium and chloride were considerably higher in goat seminal plasma than in ram semen, and the levels of calcium, sodium and magnesium were about the same as in ram semen.
4. General properties and chemical composition of the accessory sexual gland secretions of goat were as ows.
The pH value of the Cowper's gland secretion was extremely higher than that of the seminal vesicle or the prostate gland, being 8.3 (electrode) on the average of 7 Cowper's glands. Concen-tration of total nitrogen was higher in the secretion of each gland than in the seminal plasma, and the non-protein nitrogen level (T. C. A. soluble) was high especially in the secretion of the Cowper's gland. Most of fructose and citric acid were detected in the seminal vesicle secretions being only in a small amount in the other two glands. Concentration of the total or the acid-soluble phosphorus was rather low in the secretions of any of these three glands than in the seminal plasma. Calcium and potassium were found in relatively large amounts in the Cowper's gland secretion, and the magnesium level was extremely high in the seminal vesicle secretion.
From the above results the chemical composition of goat semen was clarified considerably, and it seems that there was no marked difference in the semen characteristics between goat and other farm animals such as bull and ram especially with reference to the presence of an egg-yolk coagulating enzyme.
