Acta Vet. Brno 2019, 88: 401-412
Reproductive characteristics of wild boar males (Sus scrofa) under different environmental conditions
The wild boar population has been on a permanent increase over the last decades, causing conflicts with the requirements of modern human society. Existing effort to stabilize wild boar numbers generally fails with one of the causes being the high reproductive potential of wild boar. The aim of this study was to assess the onset of sexual maturity in wild boar males with regard to age, physical frame and environmental conditions on the basis of testicle development and sperm production. This study assessed the dimensions of gonads and the occurrence of sperm in boars caught during common hunts. Environmental conditions were found as an important factor for growth and sexual maturity of wild boar males. The body weight was a more important factor for sperm production than the age of young wild boar males. The weight threshold for sperm production in the testes was 29 kg of live weight, which corresponds to 6 months of age on average. This study has proven that environmental conditions are a significant factor affecting the physical development of male wild boars, more specifically the growth rate of their body frames and the onset of sexual maturity. In a better quality environment boars grow faster and enter puberty at an earlier age. Poor food supply and/or high hunting pressure result in slower body and testicular growth, as well as the production of sperm at a later age (approx. 2-3 months later).
Keywords
Testicles, gonads, mating season, sperm, feeding, body weight.
Funding
This study was supported by the Specific University Research Fund of the FFWT Mendel University in Brno, Grant No. LDF_PSV_2016013. Spaces for laboratory analyses were provided by the Department of Morphology, Physiology and Animal Genetics, and Department of Animal Breeding, Faculty of AgriSciences, Mendel University in Brno. We also thank Zuzana Rečková for help with laboratory analyses and Ken Urquhart for language revision.