June, 1956]
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further tests, they were able to show that high sexual activity with oestrous cows
was not due solely to the special odour of cows on heat, but appeared to be due
to the constant change of cows that provided the novel and varied stimuli. In
natural mating each cow by itself provides the novel and varied stimuli. But
in artificial service, since collections are taken under uniform and unvaried sets of
conditions, a factor of importance in the initial stages to train the bull to the technique
through conditioned reflex, depending upon the length of service and the nature of
the bulls, the reaction of the bulls is likely to get 'dulled'. It is then that the change
of stimuli are best calculated to produce the desired results. Evalmpieva [1945]
working on rabbits found direct correlation between the appearance of internal
inhibition of sexual reflexes on the one hand and the monotony of the mating environ-
ment on the other. The more stereotyped and uniform were the conditions under
which matings took place sooner the inhibition occurred. An increase of the inter-
val between each mating to 48 hours as well as the alteration of environmental
conditions slowed down the development of inhibition. The latter was evoked at
an unequal rate in different males, failing to develop in some animals on account of
variable type of nervous activity (temperament), peculiar to each animal. Smirnov-
Ugrjumov [1945] classified temperamental types into four classes : (1) impetuous
or uncontrollable, (2) lively, (3) quiet and balanced and (4) weak. Males of type
(1) were not liable to develop inhibition due to external factors and were incapable
of developing differential inhibition resulting in extinction of sexual reflexes, and
did not show any signs of internal inhibition clue to frequent matings in the same
environment. Those of type (2), exhibited a transitory inhibition due to external
factors, readily developed both positive and inhibitory sexual reflexes and quickly
showed the symptoms of internal inhibition, if mated frequently in the
same environment. The type (3) behaved mainly as type (2) but development of
positive and inhibitory sexual reflexes occurred more slowly. Those of type (4)
rapidly developed inhibition in sexual reflexes as a result of external and internal
factors.
The buffalo bulls in our experiments belonged to types (2) and (3). Types (1)
and (4) were absent. Since we had tried only the effect of short term changes of
sexual stimuli and change of environment and given only one chance consisting of
three ' tries ' of five minutes duration, the effect of such changes could best be
assessed through the reaction time values. In general, it was noticed that those
with lower sex-drive responded better than those with higher sex-drive. These
results bear out the findings of the Russian workers. But unlike the Russian
workers, we had employed a delicate experimental design and analysis of the results
showed significant variation only in the following : (i) reaction time when a bull
was substituted for the routine anoestrous female in Experiment I(a), (ii) percentage
of abnormal sperm in the second ejaculate of Experiment I(b), (iii) percentage of
abnormal sperm in the first ejaculate of Experiment III, (iv) initial motility in first
ejaculate of Experiment IV and (v) sperm concentration in the first ejaculate of
Experiment VI. No significant variation could be detected in other cases.
The significant change in reaction time when the bull was substituted for the
routine anoestrous cow was in all probability due to radical change in. teasers. The
negative results obtained when the experiment was repeated indicate that probably