Reproductive Characteristics of Abyssinian Jennies Exposed to Stallions and Jackasses

Abstract

The aim of the study was to describe the intraspecies and interspecies sexual interactions and reproductive features Abyssinian type jennies exposed to jackasses and stallions. Twenty post-pubertal jennies, 3 jackasses and 4 stallions were used in the study. Jennies were divided in to two groups of ten each (stallion group and jack group). PGF_2a was used to induce heat. A vasectomized jackass was used to assist heat detection. Jennies in the jack group were bred by two jackasses and jennies in the stallion group were bred by a stallion. Mating was on the 6^th and 8^th days after PGF_2a injection and within the last three days after spontaneous return to heat. The durations of estrus and the estrus cycle were 7.4 ± 0.9 (mean ± SD) and 24.3 ± 2.1 (mean ± SD) days respectively. All jennies were receptive to jackasses but not to stallions. The number of cycles per pregnancy in the intraspecies mating was lower than the number of cycles in the interspecies mating (p < 0.05). The lengths of gestation of jennies in foal with jackasses and a stallion were 370.2 ± 4.5 (mean ± SD) and 330 days respectively. The mating resulted in five donkey foals and a hinny. The study showed that Abyssinian jennies have a high intraspecies reproductive potential but low pregnancy rate and abortion appear limitations in interspecies hybridization.

Key words: Hinny, Jackass, Jenny, Reproduction, Stallion