318
SEMEN QUALITIES OF BUFFALO-BULLS [ Vol. XXV, Part IV,
Besides the above mentioned semen characteristics, the reaction time of the
animals was also noted at the time of collection of the semen. Reaction time
as stated by Mukherjee and Bhattacharya [1952], is the time interval between the
release of the bull near the cow and the actual moment of ejaculation. This has
been expressed in seconds. During the experimental period, daily records of maxi-
mum and minimum air temperatures and that of relative humidity were kept.
RESULTS
Data regarding the average reaction time and semen attributes of the buffalo-
bulls together with the meteorological data of each month are presented in Table I.
Examination of data reveals that there did not exist any relationship between the
reaction time and the quality and quantity of semen produced. No marked varia-
tion seems to exist in volume of semen and initial motility of spermatozoa.
Average monthly variations in reaction-time, semen characteristics, air
temperature and relative humidity are presented in Fig. I. From the graph it is
apparent that the curves for sperm concentration and total number of spermatozoa
show a uniform trend of variation. Curves for air temperature and relative humidity
are also uniform and show monthly variations. It seems from Fig. 1 that when the
relative humidity increases the air temperature decreases.
Four seasons were distinguished for the purpose of studying the effect of seasons
on reaction-time and semen characteristics as reported previously by Mukherjee
and Bhattacharya [1952] and Shukla and Bhattacharya [1952, a and b]. They
are August to October—autumn, November to January—winter, February to April—
spring and May to July—summer.
The data on average reaction-time and semen characteristics and the meteor-
ological data during the months and the seasons were subjected to analysis of
variance. The summary of the results of analysis are presented in Table II. It
is seen that between the two experimental years, there were highly significant
variations in reaction-time and in all the characteristics of semen except in pH and
sperm concentration. Among the seasons, variability in reaction-time was
significant. Variations in all characteristics of semen except volume and pH. were
highly significant. Variations in initial motility, sperm concentration and
percentage of abnormal spermatozoa were highly significant and the total number
of spermatozoa significant due to the interaction between seasons and years.
Between months within season, highly significant variations were found in pH
of semen, sperm concentration and percentage of abnormal spermatozoa. As regards
the average air temperature and relative humidity, it may be seen from the Table
that their variations were highly significant between seasons only and that there was
no significant variation between the two experimental years.
To test the differences between significant and highly significant factors as
presented in Table II, critical difference (C. D.) of the variable factors between seasons
and years at 5 per cent level of probability have been worked out and are presented
in Tables III and IV. From the Tables, it will be seen that average figures under the
same bar did not vary at 5 per cent level. Table III, shows C. D. of variable factors