Post‐mortem examination of the reproductive organs of female wild boars (Sus scrofa) in Sweden

Abstract

In recent decades, wild boars (Sus scrofa) have increased in numbers and distribution in Europe. Compared to other wild ungulates of similar body size, wild boars have a high reproductive capacity. To increase the knowledge of wild boar reproduction, the objective of this study was to investigate characteristics of reproductive organs, and to provide information on the occurrence of abnormalities in reproductive organs from free-ranging female wild boars. Between December 2011 and December 2015, reproductive organs from female wild boars (>30 kg body weight), were collected during hunting in four Swedish counties at estates where supplementary feeding was applied. The organs were macroscopically examined and measured. The stage of the reproductive cycle was defined according to the ovarian structures and in relation to uterus characteristics. Observed abnormalities were noted. The results from 569 animals that met the requirements to be included in this study showed significant differences in weight and length of the uterus between the various reproductive stages. Sampling region had significant effect on these differences. Abnormalities in the reproductive organs were present in approximately 10% of the examined animals. The prevalence of abnormalities increased significantly with age and was significantly affected by sampling region.

The reproductive pattern and potential of free ranging female wild boars (Sus scrofa) in Sweden

“…The collected reproductive organs were frozen at −20 °C until the macroscopic laboratory examination [ 7 ]. The size and weight of the uterus and ovaries were recorded as were the ovarian structures (follicles and corpora lutea, CL).…”

“…The uteri were cut open and the contents examined. The reproductive stage was determined based on the data from the macroscopic examination [ 7 ]. Animals in prooestrus, oestrus, metoestrus and dioestrus were classified as cyclic.…”

“…To understand the population dynamics of a game species such as the wild boar, knowledge of its reproductive period, oestrus cycle and reproductive success is essential [ 7 , 8 ]. Wild boar biology has been studied in several countries with a long history of wild boar populations.…”

“…The knowledge about Swedish wild boar and its management is limited, and only a few studies have been published. These studies have mainly described wild boar movement patterns, behaviour, and habitat selection [ 17 – 20 ], but few include data on reproduction [ 7 , 21 ], i.e. reproductive performance and reproductive potential of the species in Sweden.…”

An approach to stress assessment during hunting: Cortisol levels of wild boar (Sus scrofa) during drive hunts

“…Laboratory analysis was conducted at the endocrinological laboratory of the clinic for cattle of the University of Veterinary Medicine Hannover, Foundation using radioimmunoassay (Cortisol RIA KIT, Beckmann Coulter, Inc., Krefeld) while following the instructions from the manufacturer. Additionally, we sampled uteri and ovaries for the ongoing analysis of the reproductive status of female wild boar [ccording to techniques described in 27,35,36]. With this information, we categorized female wild boar as potentially pregnant (several corpora lutea, but no visible embryos), pregnant (developed foetuses) and non-pregnant (no visible corpora lutea or foetuses).…”