Growth and Development: Postnatal Development as a Harbinger of Future Performance.

This article presents abstracts of various papers related to cattle growth and development, that were presented during the symposium held on July 26, 2005, Cincinnati, Ohio, which was organized by the American Dairy Science Association, the American Society of Animal Science and the Canadian Society of Animal Science. One of the papers presented is "Hormone and Growth Factor Regulation of Tissue Remodeling in the Mammary Gland," by D. Flint, G. Allan, J. Beattie and others. Insulin-like growth factor binding protein-5 (IGFBP-5) production increases dramatically during forced involution of the mammary gland in rats, mice and pigs. Growth hormone increases production of the survival factor IGF-I, whilst prolactin enhances the effects of GH by inhibiting IGFBP-5 synthesis which would otherwise prevent the actions of IGFs. Another paper is "Effects of Modified Calf Growth on Mammary Development, Endocrine Physiology, and Performance," by M. Vestergaard, S. Purup and others. The purpose of rearing heifers comprises a utilization of the genetic potential of the animal to achieve the most favorable body and mammary gland development by optimizing feeding and rearing conditions.