Influence of biological and environmental factors on the hormone levels in ovine males breeds of double aptitude (meat and milk) | Influencia de los factores biológicos y ambientales sobre los niveles hormonales de machos en razas ovinas de doble aptitud leche-carne
2009
Palacios, C., Universidad de Salamanca (España). Facultad de Ciencias Agrarias y Ambientales | Martín Gil, J., Universidad de Valladolid, Palencia (España). Escuela Técnica Superior de Ingenierías Agrarias | Hernández Navarro, S., Universidad de Valladolid, Palencia (España). Escuela Técnica Superior de Ingenierías Agrarias | Correa Guimaraes, A., Universidad de Valladolid, Palencia (España). Escuela Técnica Superior de Ingenierías Agrarias | García, R.V. | Lafuente, M.A.
In this study we compare, in addition to testicular perimeter, plasmatic concentrations for cortisol and sexual hormones with sexual activity, age and breed in ovine males. Blood extractions have been made in December and for the analytical determinations electrochemiluminescent assays were used. The studied animals have been 26 males of Churra breed, 8 males of Assaf breed, and 18 males of Castilian breed. Sexually active males show serum hormonal concentrations greater than those of passive males in all studied parameters (p<0.001). The level of testosterone (ng/ml) of passive males of Assaf breed (6.22) is greater than the one of those of Churra breed (1.27), p<0.01. In active males, those of Churra breed have greater concentration (6.3 ng/ml) than those of Castilian breed (1.3 ng/ml), p<0.001. Older males exhibit greater testicular perimeters (31.21 cm) than those of youngest (29.57 cm), and testosterone levels are also higher than youngest ones (4.5 vs 1.2 ng/ml), p<0.05. The stress of the animals, evaluated through the serum cortisol (Möstl and Palme, 2002), is dependent on sexual activity (1.6 vs 0.86 ng/ml, p<0.05). In conclusion, the studied factors have proven to affect the testicular size and sexual hormones and cortisol levels (or their state of stress).
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