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Both the egg and the broiler producers require a continuous supply of commercial chicks as in the best season throughout the year. To comply with their requests, hatching eggs which were assured of high fertility and hatchability should be produced by the breeder.
Seasonal differences of fertility and hatchability of eggs obtained from the natural mating (NM) and the artificial insemination (AI) methods were inquired, using the data during a four-year period from 1960 to 1963 at this Institute and the private hatchery in Chiba prefecture.
Four purebreds, White Leghorn (WL), New Hampshire (NH), Barred Plymouth Rock (BP), White Cornish (WC), and 6 crossbreds, WL ?? ?? xNH_ ?? ?? _, NH ?? ?? ×WL ?? ??, WL ?? ?? ×BP ?? ??, BP ?? ?? ×WL ?? ??, (WC ?? ?? )x(WL ?? ?? xNH ?? ?? ), (WC ?? ?? )×(WL ?? ?? xBP ?? ?? _)( ?? ?? ), were used in this study.
A total of 2, 259, 851 eggs were used in the four years-1, 932, 366 and 327, 485 eggs from the NM and AI groups, respectively.
1. Average percentages of fertility in the NM and AI groups were 83.7 and 81.9, respectively, and no significant difference was found between them.
2. The seasonal ranking of the fertility in the NM group coincided with that of the fertility in the AI. The highest fertility in both the NM and AI groups occurred in spring season, representing 86.5% and 83.9%, respectively. The percentages of the fertility in fall and winter in the NM group were 84.2 and 82.2, respectively, and those in fall and winter in the AI were 83.1 and 81.7, res-pectively. The lowest fertility in both the NM and AI groups was observed in summer, showing 81.8% and 78.9%, respectively. There found a significant difference at 1% level among the seasons in the NM group, and that at 5% level in the AI by the analysis of variance.
In the monthly fertility, the highest in the NM was observed in April and May (86.8%), and that in the AI occurred in October (84.8%). The lowest fertility in the NM was found in August (79.1%), being July (77.9%) in the AI. Significant differences at 1% level were detected among each month in both groups.
3. The percentages of the fertility in each breed in the NM group, as shown in Tables 1 and 2, were 87.3 in WL x WL, 84.5 in WL x BP, 83.1 in BP x BP, 82.8 in NH x NH, 82.1 in NH x WL, 81.8 in WLxNH and 80.6 in BPxWL, and there observed a significant difference at 1% level among these breeds.
4. Average percentages of hatchability of the fertile eggs in the NM and AI groups were 86.8 and 87.7, respectively, and no significant difference was observed between them.
5. The highest hatchability in the NM group was observed in spring (88.7%), the second in winter (87.5%), the third in summer (85.6%), and the lowest in fall (85.5%), showing a significant difference at 5% level among the seasons. The highest hatchability in the AI group occurred in fall (88.5%), the second highest in spring (88.2%), the third in winter (87.3%), and the lowest in summer (86.9%), and no significant difference was found among them. In the monthly differences of the hatchability in the NM group, the value in March was the highest (89.1%) and that in September was the lowest (83.2%), showing a highly significant difference among each month. The highest hatchability in the AI group was observed in May (93.3%), being the lowest in January (82.3%), and there also existed a highly significant difference among each month.
6. In the breed differences of the hatchability in the NM group, crossbred of NHxWL showed the highest (90.6%) and that of WLxBP was the lowest (81.7%), being a significant difference at 1% level among the breeds.
7. While average percentage of the early dead germ in the NM group was 7.5, that in the AI was 9.3. In the seasonal differences, the percentage of the early dead germ in the former group was the lowest in spring (6.2%), showing the highest in summer (8.9%).

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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.

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Some of the factors affecting the activity of the egg-yolk coagulating enzyme in goat semen have been reported in the previous report of this study. This experiment was performed to clarify the variations in the enzyme activity owing to the collection time and the season when the semen was collected throughout the year, March 1960 to April 1962. Besides, some seminal constituents, fructose, citric acid and protein, that are probably secreted from the seminal vesicle were determined quantitatively in comparison with the activity of the egg-yolk coagulating enzyme which may be secreted from the Cowper's gland. And thus we intended to examine the presence of any relationship between the seminal vesicle constituents and the Cowper's gland secretion.
Principal results obtained are as follows.
1. Activity of the egg-yolk coagulating enzyme was significantly higher in the breeding season, August to March, than in the non-breeding season in each goat.
2. It was recognized that the enzyme activity of the seminal plasma was enhanced significantly as the collection time was advanced, from the results of averaging 110 trials of three successive ejaculations on three goats throughout the year.
3. Concentrations of fructose, citric acid and protein in seminal plasma were significantly higher in the breeding season than in the non-breeding season as in the case of the coagulating enzyme, but there was no significant difference among the collection time, 1 st, 2 nd and the 3 rd in contrast to the results obtained in the enzyme activity. So it was suggested that some difference might be seen in the secreting mechanism between the seminal vesicle and the Cowper's gland

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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.

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