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Research r...FinishersTrial report 955

Trial report 955: Screening of organic entire males

Rejection rates due to boar taint are high among organic entire males and vary greatly between herds. Research showed that if rejection was based on skatole, 18% were rejected, and if also based on “Human nose” 26% were rejected.


Many organic entire male pigs produced in Denmark are rejected at slaughter due to boar taint. Research demonstrated that if rejection was based on skatole levels (>0.25 ppm), 18% of the male pigs were rejected, and if rejection was also based on the Human nose method, 26% of the male pigs were rejected. If androstenone levels were also included in the evaluation, rejection rates reached 68%.

Entire males from six organic herds were slaughtered and carcasses were subject to analysis of skatole and to the Human nose method at the slaughterhouse. In addition, skatole, indole and androstenone were analysed at a laboratory. To ensure that pork is free of boar taint, it will be necessary to analyse for both skatole and androstenone in the future. Today, pigs weigh more and are therefore closer to sexual maturity at slaughter than they were years ago. Organic male pigs grow more slowly, are older at slaughter and are fed a different type of diet than conventional pigs, and they are therefore expected have higher levels of skatole as well as androstenone.

If the limit for rejection at the slaughterhouse is 0.25 ppm for skatole, averagely 18% - varying from 4% to 27% - of organic entire males will be rejected. If also the Human nose method is applied, rejection rates averaged 26% varying from 10% to 39%. Today, male pigs from conventional farms are rejected at slaughter due to skatole levels above 0.25 ppm, but for these farms it is still profitable to produce entire males as they can do so with fairly low rejection rates (4-5%).

If rejection is based on skatole and androstenone (skatole >0.25 ppm; androstenone >1.00 ppm), 68% of the organic entire males would be rejected.

The correlation between skatole analysed at the slaughterhouse and at a laboratory was close to 100%, which confirms identical outcome of both methods. The correlation between the Human nose method and skatole levels shows that the Human nose method accounts for approx. 60% of the variation in skatole and approx. 50% of the variation in androstenone levels.

Financial support

The project was financially supported by the Pig Levy Fund and the Ministry of Food, Agriculture and Fisheries of Denmark, and the European Agricultural Fund for Rural Development. Project ID VSP/09/10/48.2.


Updated: 01.11.2012


Hanne Maribo

Chief scientist, PhD

Tel.: +45 3339 4390