84
SEASONAL VARIATION IN SEMEN QUALITY
[Vol. XXII, Part II,
As has been stated before the total number of spermatozoa was calculated by
multiplying the density of the ejaculate by its volume. It was expected, therefore,
that in bulls, showing significant differences in volume but not in sperm concentra-
tion the total number of spermatozoa with larger volume of ejaculate would be
higher. This was found to be true in bulls 248 and 187. Sperm-concentration of
these two bulls did not vary. However, as bull 187 was much superior to bull 248
in volume, the total number of spermatozoa was significantly greater than that of
248 which had the lowest semen volume. There was no significant variation in
the total number of spermatozoa between bulls 187 and 200. This was perhaps due
to the fact that the volume of semen of the latter was significantly less than that
of the former although its sperm concentration was significantly higher. Bulls
194 and 195 did not vary in this characteristic as there was neither significant
variation between their semen volumes nor between their sperm concentrations.
Between bulls 195 and 240 there was not significant variation in sperm concentra-
tion. Although there was a significant variation in their volume of semen, the
variation was not so great as between bulls 187 and 248. It was prehaps due to
this reason that no significant variation in the total number of spermatozoa between
bulls 195 and 240 was observed.
Regarding the blood constituents it will be seen from the table that there was
a very close relationship between cell volume and haemoglobin contents. Bulls
having higher concentration of haemoglobin also had higher cell volume in blood.
Judged by these two characteristics, the quality of blood of bull 187 was poorest.
Furthermore, the semen quality of this bull as regards initial motility and sperm
concentration was very poor and the pH of semen was high. Bull 248 was signi-
ficantly inferior to bulls 240 and 194 for blood as well as for semen attributes. Bull
194 which showed highest concentration of haemoglobin and cell volume in blood
also showed highest sperm concentration in semen. Its total number of sperma-
tozoa did not vary significantly from that of bull 240 which showed the highest
number of spermatozoa.
From the records of bulls 187, 194 and 248 it appears that there was a direct
correlation between semen and blood quality of bulls. Had it been really so, bulls
200 and 248 which did not vary significantly in their blood constitutions should
not have varied in their semen quality as well. But bull 248 was the poorest of all
for volume and total number of spermatczoa. The pH value of semen was also
high and there was not significant variation in sperm concentration between 248
and 187 which had the lowest sperm concentration. Similarly, bull 195 did not
vary significantly in blood picture from bull 248 but its semen quality was decidedly
superior to bull 248.
Table V shows C. D. at 5 per cent level of variable factors between years. From
the table it will be seen that during the first year of the experiment the initial
motility of spermatozoa was significantly higher than in the second year, whereas,
the pH value in the second year was more than in the first year. Blood samples
of the animals during 1946-47 were richer in haemoglobin and cell volume than in
1945-46. It is apparent, therefore, that although the general conditions of the