Potential for a Genetic Solution for Boar Taint in Canadian Pigs

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1 Potential for a Genetic Solution for Boar Taint in Canadian Pigs M. Jafarikia 1, J. Squires 2, F. Schenkel 2, F. Fortin 3 S. Wyss 1, W. Van Berkel 4, B. Sullivan 1, T. Oke 5 1 Canadian Centre for Swine Improvement, Ottawa ON; 2 University of Guelph, Guelph ON 3 Centre de développement du porc du Québec, Québec QC; 4 Western Swine Testing Association, Lacombe AB; 5 Ontario Swine Improvement, Innerkip ON The Problem of Boar Taint Boar taint: Boar taint is an unpleasant odour produced by the accumulation of androstenone and skatole in fat tissues of intact male pigs. Boar taint compounds are pheromones secreted by boars to attract the sows in the wild. However, meat produced from intact males containing too much taint can affect the eating quality of pork. Current solution of boar taint in Canada: Castration is a common practice for preventing boar taint. However, alternative solutions are of interest due mainly to animal welfare concerns. Potential long-term solution: Genetic selection is a potential solution for decreasing boar taint levels in meat from intact males. Technologies are available to scan animals for candidate genes associated with boar taint, which would allow for selection against alleles responsible for increased levels of androstenone and skatole. Currently there are more than 100 single nucleotide polymorphisms (SNPs) associated with boar taint identified at the University of Guelph. Potential negative impact of a genetic solution: Since boar taint compounds are pheromones, there is a concern that selection against boar taint alleles may negatively affect traits related to reproductive performance. However, previous research at the University of Guelph has found relatively weak correlations (unpublished data). Presented at the CMSA/CMC 2013 Technical Symposium Banff, Alberta Ongoing Research Objective: To provide tools for reducing boar taint using SNP markers in genes involved in the synthesis and degradation of boar taint compounds. Table 1: Genotyping animals Breeds Duroc Landrace Yorkshire Target Genotyped to study the association of SNPs with performance traits and 700 to study the association of SNPs with androstenone and skatole. Table 2: Measuring boar taint levels Breed Duroc Landrace Yorkshire Androstenone Boars Average(ng/g) 1, %Acceptable Skatole Boars Average(ng/g) %Acceptable Number of boars with taint compound measured to date (target is 700 per breed). 2 maximum acceptable levels for androstenone and skatole were 1000 ng/g and 200 ng/g, respectively. Preliminary Results SNP frequency: Animals were genotyped for 77 SNPs out of an initial 122 selected candidate SNPs. Preliminary analysis found 52, 69 and 70 SNPs having minor allele frequencies greater than 1% in a sample of 316 Duroc, 493 Landrace and 513 Yorkshire pigs, respectively. Table 3: Percentage of boars with androstenone and skatole above (high) or below (low) acceptable levels Androstenone High Low Skatole High 6% 4% Low 30% 60% Conclusions and Next Steps In comparison to the levels of skatole, more pigs pg with higher levels of androstenone observed (Table 3). The observed variation of boar taint compounds and genotype frequencies support the potential of using genetics for lowering the levels of boar taint in Canadian pigs. Association analysis will be followed by validation of predicted androstenone and skatole levels compared to actual phenotypes on an independent sample of 900 additional boars. Acknowledgements: Financial support provided by the Canadian Agricultural Adaptation Program (CAAP),regional swine improvement centres across Canada and participating Canadian breeders.

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7 New Project Proposal Alternatives for the control of boar taint in Canadian pork 1,000 commercial pigs (females, intact males, barrows and immunocastrates) Two groups of sires pre-selected based on their boar taint genotype Individual id performance including feed intake, behaviour, growth and fat/lean/imf deposition Full carcass and meat quality assessment Methods to measure boar taint on carcasses Sensory analysis of cooked pork produced during commercial trials