The meat of entire male pigs can sometimes have an unpleasant odour when fried. This is the main reason for castrating young male pigs in Denmark. Being neutered is a painful experience for the young pig and means extra work for the farmer. Moreover, several main actors in the pig meat chain have agreed on a plan to voluntarily end the surgical castration of pigs in Europe by 1 January 2018. The quest for alternatives has therefore begun.

One approach to solving this problem is to reduce the concentration of the substances that create the foul smell and that is what scientists from Aarhus University are focusing on in a new project funded by the Green Development and Demonstration Programme under the Ministry of Food, Agriculture and Fisheries.

The project seeks to find out whether the substances that taint the meat can be taken out of circulation by using adsorbents. Adsorption occurs when a material binds another substance to its surface. One of the substances that causes boar taint, which the scientists are putting under the microscope, is androstenone.

- Boar taint in the meat is caused by two components: skatole and androstenone. While much research has been carried out on skatole, we have very little knowledge on androsterone, says senior researcher Nuria Canibe from the Department of Animal Science at Aarhus University and leader of the research project.

Boar lure

Androstenone is a substance produced by the mature male pig, which he uses, among other things, to attract sows in heat. Androstenone is found in high concentrations in the boar's saliva. When a sow that is ready to mate detects the "scent", she will stand stock-still so that the boar can mount her. The boar’s excess androstenone can be found in the blood plasma and adipose tissue, which is why it taints the meat.

Most people do not have the same liking for the smell of androstenone as the sow on heat, so it is important to avoid it in the meat. This could possibly be done by feeding the animals an adsorbent.

New research shows that adsorbents such as activated carbon can reduce the concentration of androstenone in fat and blood plasma and thus reduce boar taint in the roasted meat. Activated carbon has been used for centuries to bind moisture, odours and noxious substances and to clean air and water.

The scientists will examine whether androstenone is absorbed from the gut. They will identify how much of the adsorbent effect can be attributed to the binding of androstenone in the gut and to the binding of sex hormones that could potentially affect the metabolism of androstenone in the liver. Finally, the scientists will develop methods to identify adsorbents that have the potential to reduce boar taint.

What is the difference between absorption and adsorption?

For further information please contact: Senior researcher Nuria Canibe, Department of Animal Science, email: Nuria.Canibe@agrsci.dk, telephone: +45 8715 8058