Earlier studies at Aarhus University have shown that feeding pigs chicory can replace castration. Scientists have now taken a step closer to understanding how chicory affects boar taint. If the farmer feeds his pigs chicory for 14 days prior to slaughter he can avoid unpleasant boar taint in the pork. Feeding chicory is, however, not very widespread on Danish farms. One of the reasons is that chicory is too expensive.
- We can see that there is a reduced skatole content in pig’s fat and blood when the pig has been fed chicory for 14 days prior to slaughter. We investigated if this is because metabolism of the compound in the liver is improved for some reason. We conducted analyses to find the liver enzymes that metabolise skatole and androstenone and found that the enzyme content was higher and that enzyme activity was greater after feeding chicory, says PhD student Martin Krøyer Rasmussen from Aarhus University.
Skatole is produced by bacteria in the pig gut from which it is absorbed into the blood. Via the blood the compound finds its way to the liver where it is broken down by enzymes. Androstenone is also a problem. It is a pheromone produced in the pig’s testicles. It is also metabolized in the liver. Androstenene inhibits skatole metabolism. If skatole and androstenone are not metabolised in time with their production, they accumulate in the fat and give rise to boar taint in pork.
- In our studies we also found a clear effect of chicory on androstenone. We measured less androstenone in the fat, a higher level of the enzyme that metabolizes androstenone in the liver, and higher levels of the particular mRNA and protein that need to be present to build the enzyme, explains Martin Krøyer Rasmussen.
The next step for the scientists will be to find out if there is something bioactive in chicory that stimulates the liver directly or if the body is affected in some other way so that the liver reacts indirectly. The scientists will investigate this by subjecting liver cells grown in the laboratory to chicory directly and thereafter measuring if there is a higher enzyme level.
Wednesday 5 October, 2011/ Aarhus Universitet/Denmark.