Title of article :
Seasonality of reproduction in sheep
Author/Authors :
Bryant، M.J. نويسنده , , Rosa، H.J.D. نويسنده ,
Issue Information :
ماهنامه با شماره پیاپی سال 2003
Abstract :
Unlike most domestic livestock species, sheep are widely known as an animal with marked seasonality of breeding activity. The annual cycle of daily photoperiod has been identified as the determinant factor of this phenomenon, while environmental temperature, nutritional status, social interactions, lambing date and lactation period are considered to modulate it. The aim of this paper is to review the current state of knowledge of the reproductive seasonality in sheep. Following general considerations concerning the importance of seasonal breeding as a reproductive strategy for the survival of species, the paper describes the manifestations of seasonality in both the ram and the ewe. Both determinant and modulating factors are developed and special emphasis is given to the neuroendocrine base ofphotoperiodic regulation of seasonal breeding. Other aspects such as the role of melatonin, the involvement of thyroid hormones and the concept of photorefractoriness are also reviewed.
Keywords :
Complete feed , goat , Feed blocks , Nutrient utilisation , Rumen microbes
Journal title :
Small Ruminant Research
Journal title :
Small Ruminant Research