98
EFFECT OF MUSCULAR EXERCISE ON SEMEN
[Vol. XXII, Part II,
From Table I and Table II it will be seen that—(i) Volume. In both ejaculates,
the bulls in the 'no-exercise' group produced on an average slightly larger ejaculates
than the bulls in the 'exercise' group. The overall mean for the former was 1.50 c.c.
as compared to 1.29 c.c. of the latter. F. ratios as worked out separately for the
two ejaculates were found to be not significant, while in the 'pooled' analysis F. ratio
approached five per cent level of significance.
(ii) Initial motility. In the first ejaculate, the mean motility rating was slightly
higher for the 'exercise' group than the 'no-exercise' group, while it was the other way
about in the second ejaculate. The overall means for the 'exercise' and 'no-exercise'
groups were 2.33 and 2.51 respectively. The group differences when considered
separately and together for the two ejaculates were not statistically significant.
(iii) Sperm concentration. As in the case of the initial motility, sperm concentra-
tion was higher for the exercised bulls than the non-exercised ones in the first eja-
culate and vice versa in the second ejaculate. The respective overall means for the
exercised and non-exercised bulls were 557.0 M/C and 568.5 M/C. The difference
was not statistically significant.
(iv) Per cent of abnormal sperm. The percentage of abnormal sperm followed
the same trend as initial motility and sperm concentration. In the first ejaculate,
the figure was slightly higher for the exercised than the non-exercised bulls, while
in the second ejaculate, it was the other way. The overall group means for the
exercised and non-exercised bulls were 7.33 per cent and 7.47 per cent respectively.
The difference was not statistically significant.
(v) Reaction time. Exercised bulls took on an average lesser time to give both
the ejaculates than the non-exercised bulls. The overall means for the two groups
were 80.5 seconds and 86.0 seconds respectively. The difference was not statistically
significant.
(vi) Total sperm in an ejaculate. The exercised bulls on an average gave large
number of sperms in the first than in the second ejaculate as compared to the non-ex-
ercised bulls ; the overall group means for the bulls in the two lots being 758.5 milli-
ons and 909.0 millions respectively. The difference was not statistically significant.
Experiment II. The data are summarised in Table III. The figures in the table
are averages of all observations in like treatment periods. In statistical analysis,
the question arose as how best to utilise the data within a period. In the previous
experiment as only one observation per ejaculate (first or second) was available, this
did not present much difficulty. In the present experiment, 4 observations per
period of one month were available. Cochran, Autrey and Cannon [1941] who
have used a short time switch over design in studying the effect of different rations
on milk production have used the total milk production during the experimental
period as a single observation for analysis. Branton, Bratton and Salisbury [1947]
who employed a similar design in studying the nutritive requirements of dairy bulls
used in artificial insemination have used the average value instead of the total value