188
SEMEN
QUALITY
OF
GOATS
[Vol. XXII, Part III,
Volume of semen. No work has been done on seasonal influence on the
volume of semen in goats, excepting that of Phillips et al., [1943] who used only two
bucks in their experiment. The data, therefore, could not indicate clearly the
seasonal trend. The results obtained in this study are not in agreement with the
observations of Phillips and his co-workers. According to them highest average
volume was obtained in fall but in this experiment highest average volume was found
in summer. Spring was found to be the worst period by Phillips et al., for semen
volume whereas in this experiment the lowest semen volume was observed in winter.
Initial motility. Results obatined in the present experiment on seasonal
influence on motility of spermatozoa is in general agreement with those found in
rams by Shukla and Bhattacharya [1947]. But they differ from the findings of
Phillips and his co-workers [1943] in goats who obtained highest average initial
motility in fall and lowest in winter. In this experiment spring which showed
highest initial motility was also found to be the best season for sperm concentration.
Autumn was found to be the worst season for initial motility as well as for sperm
concentration. Initial motility which has been estimated in this experiment by
direct microscopical examination is the most empirical method of determining
motility. It is dependent not only on sperm concentration but also on abnormal
spermatozoa as found in some of the individual goats. Further more, cold air tempe-
rature as obtained in winter decreases the initial motility. As between winter and
summer there was no significant variation in sperm concentration and percentage
of abnormal spermatozoa, the low initial motility in winter might be due to cold
environmental temperature.
Hydrogen—ion-concentration. The average pH. of goat semen was slightly
higher than that of ram as observed by Shukla and Bhattacharya [1947]. From the
records of individual goats it has been found that like ram semen samples with high
pH values were generally associated with poorer semen quality and vice versa. It was
expected, therefore, that when there was some correlation between pH and sperm
concentration in individual animals, a significant seasonal difference should have been
observed in this factor as in case of sperm concentration. But in the present investi-
gation pH did not show significant seasonal variation. There are two plausible
explanations for this result. Firstly, it has been stated by McKenzie and Berliner
[1937] that a rough co-relation exists between pH and sperm concentration and one
cannot expect a significant coefficient of co-relation between the two. Secondly,
in the present study pH was determined with B. D. H. capillator by colorimetric
method which cannot give very accurate results.
Sperm concentration. Results obtained on the influence of season on sperm
concentration are in general agreement with those obtained by Phillips et al., [1943],
except that according to them summer was the second best season, whereas in this
case winter has been found to be the second best season. The results agree with
those reported with rams by Shukla and Bhattacharya [1947] and with bulls by
Mukherjee and Bhattacharya [1947]. These authors carried out their experiments
under the same climatic conditions in which this experiment was conducted. It
seems, therefore, that the slight difference in the results obtained in this experiment
from those of Phillips and his associates might be due to the difference in the climate
of the two places.