Genetic solution to the problem of boar taint for production of entire males P.K. Mathura,*, H.A. Mulderb , J. Ten Napelb, J. J. Windigb, R.E. Crumpb, B. van der Felsb , L. Heresc, S. Bloemhofa, M. S. Lopesa, E. F. Knola a IPG, Institute for Pig Genetics B.V., The Netherlands b Animal Breeding and Genomics Centre, Wageningen UR c VION Food Group, The Netherlands

Genetic solution to the problem of boar taint Detection methods Human Nose Scores (HNS) Androstenone and skatole Genetic parameters Production Reproduction Genomic analysis Breeding strategy

Boar taint Consumers recognise boar taint by SMELL When pork is heated

So do the slaughter plants .. Schnippe, Schweinzuch und Schweinemast, SUS, 4:2011

We did so in the “lab” Human Nose Scores (HNS) 4 3 2 1 21,972 samples Strong boar taint Boar taint Weak boar taint Deviant but not boar taint Normal pork odour 3 2 1 21,972 samples Source: Mathur et al. (2011) submitted to Meat Science journal

But the science believes in boar taint compounds Accumulated in fat Skatole (3-methyle-indole) Produced in hind gut Related “Fecal” odour Androstenone (pheromone) Produced in testes Related “urine” odour

Genetic parameters More than 7,000 boars Trait And (ln) Ska P (high Ska) HNS Androstenone (ln) .54 .33 .31 .27 Skatole (ln) .37 .41 .84 .36 P (High Skatole) .96 .40 .35 Human Nose Score (HNS) .65 .90 .93 .12 Heritabilities (diagonal), Genetic correlation (below diagonal), Phenotypic correlations (above diagonal). Significant estimates in bold Source: Windig et al. (2011) submitted to Journal of Animal Science

Production traits Genetic correlations And (ln) Ska P (high Ska) HNS Daily Gain -.06 -.10 -.15 -.07 Fat depth .17 .12 .13 .29 Loin depth -.13 -.11 N= 7,336 : Androstenone and Skatole N= 20,130 : Human Nose Scores Source: Windig et al. (2011) submitted to Journal of Animal Science

Reproduction traits Genetic correlations And (ln) Ska (ln) P (high Ska) HNS Age at first insem. (d) -.10 -.13 -.19 Gestation length (d) .06 .05 .11 Weaning to inse. Int. (d) -.09 -.06 -.11 Total number born (N) -.07 -.04 .08 Still born ln(N+1) .04 .02 Mortality (%) .12 Significant estimates in bold

Genomic information Reduction in boar taint due to a single SNP with large effect Source: Duijvesteijn et al. BMC Genetics (2010)

We used a panel of SNPs Each AI boar genotyped with a panel of boar taint related SNPs selected out of 60K SNPs

Genotypes based on selected SNP panel Genomic Breeding Values Genomic selection Phenotypic data HNS, And, Ska Genotypes based on selected SNP panel Genomic Breeding Values (GBVs)

Breeding goal Reduce “True” Boar taint Assumed to follow normal distribution Values on underlying scale based on area under the curve

Sorting of LBT boars a) b) c) LBT = Low Boar Taint ASI compounds (carcass and biopsy) b) TOPIGS LBT-boar Human nose scores c) LBT = Low Boar Taint Genomics

Effect of genetic selection Human Nose Scores Effect of LBT boars (%) 4 Strong boar taint Boar taint Weak boar taint Deviant but not boar taint Normal pork odour - 41% - 40% - 19% - 8% + 5% 3 2 1

Boar taint can be reduced through genetics Conclusion through a combination of: A) Boar taint compounds (And, Ska) B) Human nose scores C) Genomic information Boar taint can be reduced through genetics

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