Submitted to: Encyclopedia of Animal Science
Publication Type: Book / Chapter
Publication Acceptance Date: 8/19/2003
Publication Date: 11/1/2004
Citation: Klindt, J.M. 2005. Hormones: Protein. In: Pond, W.G., Bell, A.W., editors. Encyclopedia of Animal Science. Marcel Dekker,Inc., New York, NY. p. 520-522.
Technical Abstract: Hormones are produced and released from endocrine glands directly into the bloodstream and transported to distant tissues. They direct physiological processes to maintain homeostasis and direct growth, developmental, and reproduction. Hormone secretion is regulated by genetic and environmental inputs and constant negative and positive feedback control by metabolites, neurotransmitters, and other hormones. Protein hormones are polymers of amino acids that effect their actions through binding to cell surface receptors. Protein hormones are released from almost all organs and tissues and have endocrine, autocrine, and(or) paracrine actions in regulation of all physiological processes in animals, functioning as stimulatory and inhibitory regulators. Currently, protein hormones are used in animal production for enhancement of milk production in dairy cows, improvement in efficiency of body weight gain and carcass composition in pigs in Australia, estrous synchronization and induction, and suppression of boar taint in intact Australian male hogs. With full understanding of their regulation and actions and development of recombinant and transgenic technologies, protein hormones may be harnessed to provide greater control over productive processes in livestock.