Genetic solution to the problem of boar taint for production of entire malesP.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 Netherlandsb Animal Breeding and Genomics Centre, Wageningen URc 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”

21,972 samples

Strong boar taint

Boar taint

Weak boar taint

Deviant but not boar taint

Normal pork odour

3

21

0

4

Human Nose Scores (HNS)

Source: Mathur et al. (2011) submitted to Meat Science journal

•Androstenone Androstenone (pheromone)(pheromone)

•Produced in testesProduced in testes

•Related “urine” odourRelated “urine” odour

•Androstenone Androstenone (pheromone)(pheromone)

•Produced in testesProduced in testes

•Related “urine” odourRelated “urine” odour

But the science believes in boar taint compounds

•Skatole (3-methyle-Skatole (3-methyle-indole)indole)

•Produced in hind Produced in hind gutgut

•Related “Fecal” Related “Fecal” odourodour

•Skatole (3-methyle-Skatole (3-methyle-indole)indole)

•Produced in hind Produced in hind gutgut

•Related “Fecal” Related “Fecal” odourodour

Accumulated in fatAccumulated in fat

Genetic parameters

TraitAnd (ln)

Ska (ln)

P (high Ska)

HNS

Androstenone (ln) .54 .33 .31 .27

Skatole (ln) .37 .41 .84 .36

P (High Skatole) .33 .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

More than 7,000 boars

Production traits

And (ln)

Ska (ln)

P (high Ska)

HNS

Daily Gain -.06 -.10 -.15 -.07

Fat depth .17 .12 .13 .29

Loin depth -.13 -.10 -.13 -.11

Genetic correlations

Source: Windig et al. (2011) submitted to Journal of Animal Science

N= 7,336 : Androstenone and Skatole N= 20,130 : Human Nose Scores

Reproduction traits

And (ln)

Ska (ln)

P (high Ska)

HNS

Age at first insem. (d) -.10 -.13 -.19 -.10

Gestation length (d) .06 .06 .05 .11

Weaning to inse. Int. (d) -.09 .11 -.06 -.11

Total number born (N) -.07 .06 -.04 .08

Still born ln(N+1) -.07 .04 -.13 .02

Mortality (%) .12 .02 .05 -.09

Genetic correlations

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

Genomic selection

Genomic Breeding Values (GBVs)

Genomic Breeding Values (GBVs)

Phenotypic data

HNS,

And, Ska

Genotypes based on selected SNP panel

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

TOPIGS

LBT-boar

a)

b)

c)

Genomics

Human nose scores

ASI compounds (carcass and biopsy)

LBT = Low Boar Taint

Effect of genetic selection

Strong boar taint

Boar taint

Weak boar taint

Deviant but not boar taint

Normal pork odour

3

21

0

4

Human Nose Scores

- 41%

- 40%

- 19%

- 8%

+ 5%

Effect of LBT boars (%)

Conclusion

Boar taint can be reduced Boar taint can be reduced through geneticsthrough genetics

through a combination of:

A) Boar taint compounds (And, Ska)B) Human nose scoresC) Genomic information

Thanks !Thanks !