RELEVANT CONCEPTS OF THE SEXUAL CYCLE OF SMALL CATTLE (a discussion article is proposed for discussion)

Abstract

The article analyses the definition of the term “sexual cycle”, which was
given by many famous researchers. The classifications of the sexual cycles are given, together
with the concepts of the cycle stages. The teaching of W. Heape, who divided the sexual cycle
into several stages and gave them names and definitions, is examined in detail. They are as
follows: the first, preparatory (proestrus), the second, main stage of mating activity (estrus),
the resting stage (metestrus) and the final stage of relative rest (diestrus). It is noted that practically all foreign and Russian researchers take as a basis the staging of female sexual cycle,
which include three stages: excitation, inhibition, equilibration. Three consecutive stages of
the sexual cycle are considered: preovulatory, postovulatory, luteal, which reflect a certain
functional state of the central nervous system and its respondence to various external and internal stimuli. The definitive staging of the female sexual cycle is emphasized. The stages differ in external behavioural reactions and consecutive interior physiological processes that are
determined by a complex neurohumoral mechanism, which in turn is “triggered” by variable
environmental factors. At the same time, the article disputes the necessity of using the three
commonly used terms – heat, oestrus and ovulation to describe the sexual reflexes. It is explained that the existing division into phases (phenomena) within the stage of sexual cycle
excitation (follicle maturation and ovulation, oestrus, general reaction (sexual arousal) and
heat) is, to some extent, conventional. It is claimed that all the phenomena of the excitation
stage of the sexual cycle exist within a set of symptoms with the conventional name “heat”
(oestrus),which includes other phenomena as integral parts of it.