Review Article
Vasantha I
Abstract
The different mammalian species show a wide diversity in methods of breeding. Some of them limit their reproductive activity to certain period of the year while some breed throughout the year. This is to avoid the unfavorable environmental conditions including the non-availability of feed, water, housing etc. However, the difference in breeding strategies lies in the central regulatory system the supra chiasmatic nucleus. It controls the circadian rhythm and the nocturnal drive of melatonin. There by the GnRH/LH are under the negative feedback influence of the oestrogen. Change in daylight period is the primary factors those onsets the breeding season. In addition to it, change in oestrogen concentration, neuropeptides, Kisspeptin, GnIH, Thyroid glands and many other environmental factors like availability of food, water, housing, space and climate also influence the onset of breeding.