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Early onset of puberty in cattle: implications for gamete quality and embryo survival
Advancing the age at which puberty and subsequent sexual maturation is attained in cattle is central to the reproductive and economic efficiency of both beef and dairy production systems worldwide. Onset of puberty in both male and female cattle is regulated by a complex network of biochemical processes and involves interaction amongst many key metabolic, neuroendocrine and reproductive tissues. While our understanding of the biochemical interplay that conditions and eventually triggers the pubertal process has improved in recent years, much of the intricate mechanistic detail still eludes us. Environmental factors such as nutritional management as well as the genetic makeup of the animal undoubtedly influence the timing of puberty in cattle. In particular, there is now overwhelming evidence to support the importance of early life nutrition in regulating the timing of puberty in both bulls and heifers. For both genders, there is significant evidence that an improved metabolic status, early in calfhood, advances maturation of the hypothalamic-pituitary-gonadal axis; therefore, facilitating earlier sexual development. While advancing sexual maturation is a desirable goal, it is important that any strategy employed does not impinge upon normal gametogenesis or post-pubertal fertility potential. To this end, the aim of this review is to discuss the underlying biology of puberty in cattle with particular emphasis on the role of nutritional management during early calfhood, in (i) advancing the maturity of the hypothalamic-pituitary-gonadal axis and (ii) implications for the quality of gametes and subsequent fertility.
RD17376 Accepted 02 October 2017
© CSIRO 2017