1. The aim of this study was to investigate if male-to-female aggression of common pheasants in the course of the breeding season was related to the concentration of plasma testosterone and/or other biochemical plasma indicators in male pheasants housed in breeding cages. The influence of season on the concentration of testosterone and biochemical indicators was also investigated. 2. Males were divided into non-aggressive and aggressive groups during the breeding season based on ethological evaluation. At the beginning, in the middle and at the end of the breeding season, a blood sample was taken from all males on the same day and the concentration of selected biochemical indicators and the total circulating testosterone in the plasma were determined. 3. Male-to-female aggression during the breeding season of pheasants was not influenced by the total plasma testosterone of males. 4. The concentration of total plasma testosterone in males decreased gradually during the breeding season. 5. Male-to-female aggression of pheasants did not have a significant effect on any of the assessed biochemical indicators. 6. The influence of the breeding season affected the activities of alanine aminotransferase and aspartate aminotransferase as well as the concentrations of glucose, magnesium, potassium and chloride in the blood plasma of cage-housed male pheasants.

b Department of Animal Nutrition Faculty of Veterinary Hygiene and Ecology University of Veterinary and Pharmaceutical Sciences Brno Brno Czech Republic

c Department of Ecology and Diseases of Game Fish and Bees Faculty of Veterinary Hygiene and Ecology University of Veterinary and Pharmaceutical Sciences Brno Brno Czech Republic

Department of Animal Husbandry and Animal Hygiene Faculty of Veterinary Hygiene and Ecology University of Veterinary and Pharmaceutical Sciences Brno Brno Czech Republic

References provided by Crossref.org

The Neurobiology of Behavior and Its Applicability for Animal Welfare: A Review