The integrated metabolism of boar taint - towards developing effective strategies to reduce taint.

公猪异味是来自整头公猪（公猪）的加热猪肉产品中的异味或异味。它是由睾丸中产生的 16-雄烯类固醇（雄烯酮）以及肠道菌群从色氨酸产生的粪臭素和其他吲哚的高水平积累引起的。公猪通常会被阉割以防止公猪异味，但对阉割的动物福利担忧导致一些欧盟国家禁止手术阉割（www.boars2018.com），这在北美成为一个重要问题只是时间问题。在不进行去势的情况下控制公猪异味还可以促进生长，提高瘦肉产量，提高饲料利用率并减少饲料消耗，从而提高盈利能力，并通过降低能源成本和减少每单位猪肉的粪便量来减少猪肉生产对环境的影响。许多膳食添加剂和管理实践已被描述为在不进行去势的情况下减少公猪异味，但不同猪对这些处理的反应各不相同。 我们的实验室为了解公猪异味化合物的综合代谢做出了重大贡献，总体目标是设计有效的治疗方法来控制公猪异味。我们尚未调查公猪个体间公猪异味差异的原因。此外，公猪异味化合物代谢的某些方面尚未得到充分探索。这包括睾丸和肝脏中 16-雄烯类固醇的代谢、血浆中 16-雄烯类固醇的转运及其被脂肪细胞的摄取。肠道微生物群与猪个体的生理学之间的关系对于肠道粪臭素的产生和吸收以及肝脏的代谢也尚未完全了解。对这些过程的更全面的了解可能会为开发减少公猪异味的方法提供更多机会。我们在参与公猪异味代谢的基因中鉴定出了许多单核苷酸多态性 (SNP)，目的是开发减少公猪异味的遗传工具和选择方案。我们现在计划确定突变如何影响这些基因的表达和基因产物的活性，以便我们了解它们如何改变公猪异味的量。我们还可以利用这些基因型信息来制定有效的治疗方案，以根据基因型减少个体动物的公猪异味。我们的目标是： 1. 完成公猪异味代谢方面的表征工作， 2. 整合代谢、生理和基因组信息，以确定导致公猪异味个体差异的过程，以及 3. 利用这些信息开发新颖且有效的方法，以减少公猪异味而无需去势。

Boar taint is an off-odour or off-flavour in heated pork products from entire male pigs (boars). It is caused by the accumulation of high levels of 16-androstene steroids (androstenone), which are produced in the testis, and skatole and other indoles, which are produced from tryptophan by the gut microflora. Male pigs are normally castrated to prevent boar taint, but animal welfare concerns against castration have led several EU countries to ban surgical castration (www.boars2018.com) and it is only a matter of time before this becomes an important issue in North America. Controlling boar taint without castration would also improve growth, increase lean yield, improve feed utilization and decrease feed consumption, which will improve profitability and reduce the environmental impact of pork production from reduced energy costs and less manure per unit of pork produced. A number of dietary additives and management practices have been described to decrease boar taint without castration, but the response to these treatments varies among individual pigs. Our lab has made significant contributions to the understanding of the integrated metabolism of boar taint compounds, with the overall goal of designing effective treatment methods to control boar taint. We have not yet investigated the causes for the variations in boar taint among individual pigs. Moreover, some aspects of the metabolism of boar taint compounds have not yet been fully explored. This includes the metabolism of 16-androstene steroids in the testis and liver, the transport of 16-androstene steroids in plasma and their uptake by adipocytes. The relationship between the gut microbiome and the physiology of the individual pig on the production and absorption of skatole from the gut and metabolism by the liver is also not fully understood. A more complete understanding of these processes may provide further opportunities to develop methods to reduce boar taint. We have identified a number of Single Nucleotide Polymorphisms (SNPs) in genes involved in boar taint metabolism with the goal of developing genetic tools and selection protocols to reduce boar taint. We now plan to determine how the mutations affect the expression of these genes and the activity of the gene products, so we can understand how they can alter the amount of boar taint. We can also use this genotype information to develop effective treatment protocols to reduce boar taint in individual animals based on their genotypes. Our objectives are: 1. To complete work on the characterization of aspects of boar taint metabolism, 2. To integrate metabolic, physiological and genomic information to define the processes that lead to individual differences in boar taint and 3. To use this information to develop novel and effective methods to decrease boar taint without castration.