Effect of early androgen treatment on subsequent social behavior in heifers.

摘要: Abstract Two groups of four heifers received daily injections 0.30 mg/kg testosterone propionate in oil for 100 days, between 3 and 6 months age. other the same age only served as controls. Three to five after end treatment, a series experiments was designed compare dominance ability, aggressiveness, reactions associated with fear, treated control animals. Dominance when faced animals social experience, is higher than controls, 85% them being dominant. Treated established relationships themselves more slowly did or mixed pairs. In all fought often Those which became subordinate those When subordinate, withdrew less frequently not react aggression. dominant, were never more, sometimes less, aggressive It proposed that changes structure organized capacity become dominant at first encounter are due reduction fear induced by androgens. The acquisition rank cattle may be principally differences “emotionality” rather aggressiveness.