Vie CONG. INTERN. REPROD. ANIM. INSEM. ARTIF., PARIS, 1968, VOL. II

The "male effect" on reproductive responses
in female farm animals.

Al Brager.” NMyses S MRETSE
Royal (Dick) School of Veterinary Studies,
Edinburgh, Scotland.

 

TIntroduction

The phenomenon reported by Whitten (1957) showed
that the presence of the male mouse could exert real
influence on the manitestation of oestrus in the
female. Work by Coleman, (1950, 1951) Robinson
(1951) Riches and Watson (1954) with sheep has also
shown that the ram, by his presence among ewes,
could advance the manlfestatlons of seasonal oestrus
in ewes.

General Observations

The manner in which the male can accelerate
some influence on breeding activities in the female,
behaviourally, has been considered in relation to
several farm species. Reports have shown that the
bull among cows advances the time of the first oestrus
post partum (Petropavlovskii and Rykova, 1958;
Nersesjan, 1959). General observations suggest that
the presence of a boar among sows reduces the
incidence of anoestrus. Research in Edinburgh has
shown that the teasing of ewes, before their breeding
season, with a vasectomised ram provides teased ewes
with earLier lambing dates than control ewes when
both units have been joined together with a fertile
ram,

Observations on the Physical Nature of the Male

Effect

 

 

 

 

It has been observed that a considerable amount
of pre-copulatory behaviour in the male animal is
concerned with "nudging". Some ot this nudging is
directed at the female perineal region. This local
stimulation has been observed to have an effect on
uterine motility in the oestrous subject.

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