Browsing by Subject "Boar taint"

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    Immunocastration of male pigs
    (2020) Kress, Kevin Benjamin; Stefanski, Volker
    In Europe, male piglets have been surgically castrated for centuries in order to avoid boar-tainted carcasses and to eliminate boar-specific aggressive and sexual behavior. Surgical castration of male piglets is still legal within the European Union during the first week of life, even without anaesthesia or analgesia. These circumstances have led to increasing societal criticism, as the castration is painful and violates the physical integrity of the animals. In 2010, European stakeholders of the pork chain committed themselves voluntarily to ending surgical castration from 2018 onwards, but at present, more than 2 years later, the majority of male piglets are still castrated surgically without adequate pain relief. Immunocastration is one alternative to surgical castration or pork production with boars. Although this technique is approved for commercial use in Europe since 2009, the market shares of immunocastrates within the European pork market are very low. The main reasons for this low market acceptance are uncertainties whether immunocastration is reliable, competitive and accepted along the pork chain. The main objective of the present doctoral thesis was therefore to investigate the advantages and disadvantages of immunocastration with regard to the three pillars of sustainability aspects. The various sustainability aspects of immunocastration were summarized and reviewed. In addition, the effects of different housing conditions on the reliability of immunocastration were experimentally tested, as was the impact of housing conditions and sex group on the growth performance of male pigs. Finally, the consequences of pork production with immunocastrates and boars on the profitability of German pig production were analyzed with a simulation model using different carcass pricing systems for immunocastrates and risk scenarios for boar taint. Immunocastration is an active immunization against GnRH and consists of two consecutive vaccinations to induce antibodies which temporarily suppress testicular functions and prevent boar taint. It is a method which ensures both a high product quality and a high level of animal welfare. The impact of immunocastration on the three pillars of sustainability has been studied extensively, although a contemporary global overview of its different aspects has been missing. Performance results in immunocastrates are better than in barrows, but worse than in boars. The environmental impact of pork production with immunocastrates is lower than with barrows, but higher than with boars. The level of aggression is considerably lower in immunocastrates compared to boars. Societal concerns are mainly related to food safety, and are not supported by scientific evidence. After the second vaccination, immunocastrates switch physiologically from a boar-like to a barrow-like status. Therefore, the timing of the second vaccination is a fine-tuning tool to balance advantages of boars with their environmental and economic benefits against the increased risk of welfare problems and boar taint. Nevertheless, both the synergic and the conflicting relationships between the pillars of sustainability must be communicated along the value chain to produce tailored pork products. The present doctoral thesis shows that immunocastration can balance the advantages and disadvantages of pork production with boars or barrows, and thus serve as a sustainable alternative for the European pork chain. If used correctly, immunocastration is reliable in preventing boar taint and can be economically competitive with traditional surgical castration. Based on this thesis, future studies might investigate quality assurance systems that reliably detect non-responders, or animals that are incorrectly vaccinated, before slaughter or at slaughter line. In addition, the economic impact of switching from traditional pork production with barrows to pork production with immunocastrates along the entire pork chain should be further analyzed.
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    Male reproductive organ weight: Criteria for detection of androstenone-positive carcasses in immunocastrated and entire male pigs
    (2023) Fazarinc, Gregor; Batorek-Lukač, Nina; Škrlep, Martin; Poklukar, Klavdija; Van den Broeke, Alice; Kress, Kevin; Labussière, Etienne; Stefanski, Volker; Vrecl, Milka; Čandek-Potokar, Marjeta
    Immunocastration and rearing of entire males (EMs) are sustainable alternatives to surgical castration. However, these animal carcasses have variable risk of boar taint and should be identified at the slaughter line. We aimed to identify a simple and reliable indicator of androstenone-related boar taint by evaluating pelvic urogenital tract weight as a marker of boar-taint animals at the slaughter line. The pelvic urogenital tract, testes, and accessory sex glands of EMs and immunocastrates (ICs) were collected, dissected, and weighed, before colorimetric measurements of testicular tissue. Additionally, GnRH antibody titers and testosterone, androstenone, and skatole levels were determined. Our results showed that 81.8% of EMs had androstenone levels above the risk threshold (>0.5 µg/g fat; EM/Ahigh subgroup), whereas in ICs, the C/Ahigh subgroup with androstenone >0.5 µg/g fat accounted for only 4.3%. Androstenone levels correlated negatively with GnRH antibody titers and positively with testosterone levels and reproductive organ weights. Identification of ICs with androstenone levels above the threshold (IC/Ahigh subgroup) may be achieved via testes or pelvic urogenital tract weight measurements. However, in EMs, the latter is a more reliable parameter. A principal component analysis based on these variables and hierarchical clustering also distinguished the Ahigh from the Alow subgroup, irrespective of IC/EM. The findings highlight the possible use of pelvic urogenital tract weight along with testes weight as a simple, reliable, and efficient morphometric indicator for identifying androstenone-positive carcasses of different sex categories.