Reproductive tract morphology and symmetry of farmed common eland (Tragelaphus oryx) bulls, and their relationship with secondary sexual traits and social rank

Abstract

Common eland bulls are important game ranching animals in southern Africa, for tourism, breeding/live sales, trophy hunting, and game meat production. Interest has grown in their production potential, intensifying animal husbandry and breeding approaches. However, little scientific information is available regarding the intensive management of this species, including information regarding scientifically based selection criteria for breeding bulls. Often, simple phenotypic traits are utilised unless high-value game animals are being bred, with horn and body size often being the only traits considered for breeding bulls. This study provides basic information about the reproductive tract morphology, symmetry, and their relationships with secondary sexual traits, social rank, and temperament in common eland. Six eland males (2-2.5 years old; 203 ± 20 kg) were utilised for the study. Social rank, body weight and body condition score, temperament score, and horn size were determined before the animals were culled, and their reproductive tracts were collected for morphometric and histological evaluation. Results indicate relatively low asymmetry in bilateral reproductive tract components. Individual traits of eland bulls such as age, body weight, and social rank correlated the development of some testicular morphologies and thus may possibly be used in zoos, game ranching, and commercial production for the selection of breeding males, but not temperament and horn length, which should be carefully evaluated. Whilst this study provides baseline information from a limited sample size, further studies should incorporate the assessment of testicular hemodynamics, as well as the effects of factors such as season and androgen secretion patterns over a wider age range of common eland males and populations to provide further information for the management practices of breeding common eland bulls.

Keywords: Alternative farming species; Breeding selection; Game ranching; Temperament; Testes; Testicular morphology.