Effects of immunization against GnRH upon body growth, voluntary food intake and plasma hormone concentration in yearling red deer stags (Cervus elaphus)

Autor:	T. E. Trigg, T. N. Barry, R. W. Purchas, D. O. Freudenberger, Y. X. Sun, Peter R. Wilson
Rok vydání:	1993
Předmět:	Food intake Animal science Immunization Turnover Velvet antler Genetics Cervus elaphus Animal Science and Zoology Biology Luteinizing hormone Agronomy and Crop Science Testosterone Hormone
Zdroj:	The Journal of Agricultural Science. 121:381-388
ISSN:	1469-5146 0021-8596
Popis:	SUMMARYRed deer stags in New Zealand were given a series of immunizations against GnRH at 9–12 months of age (spring/early summer) in 1989 and 1990 and the effects upon plasma concentrations of luteinizing hormone (LH) and testosterone during the rut (15–17 months; autumn) and upon body growth to slaughter at 22 months (spring) were studied in two experiments. Control animals showed a sharp peak in plasma LH and testosterone concentration during late summer/early autumn, just preceding the rut, with scrotal circumference increasing to a maximum during the rut; body growth stopped during the rut in Expt 1 but not in Expt 2. Immunization caused the development of significant antibodies against GnRH during late spring and summer, and reduced but did not eliminate the increase in plasma LH and testosterone and scrotal enlargement leading up to the rut. Immunization did not affect body growth or voluntary feed intake during the rut in either experiment, but in Expt 1 early immunization significantly increased growth during both the pre-rut and post-rut periods. Immunization did not effect dressing out percentage, slightly increased carcass fatness in Expt 1 but not Expt 2, and reduced velvet antler growth by 12 months of age.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::09c26afb9d7f8045fccc9b72c8cef879 https://doi.org/10.1017/s0021859600085579 Zobrazit plný text záznamu