Behavior of Donkey Jacks (Equus asinus) Breeding Horse Mares (Equus caballus) at Pasture1

Abstract

The aim of this study was to describe behavior of donkeys breeding mares at pasture. Three jacks (Jl, J2, J3) were individually pastured with the same group of 30 mares on 35 hectares for 15 consecutive days each. The mean daily diurnal observation period was 11 h. Sexual behavior was observed during the precopulatory, copulatory, and postcopulatory phases. It was found that behaviors shown by jacks breeding mares were similar to those shown by jacks breeding jennies. Mares did not participate actively by showing estrus andistimulating the male. Precopulatory interactions were frequent but not prolonged, with frequent rejections by the mares. Erections occurred when jacks withdrew from the mares and the majority of the copu-lations were with the mare last teased. Behaviors shown by jacks characterized a territorial social structure. Resulting breeding efficiency was low.