Researcher Hanne Maribo: reducing boar taint through feed

Hanne Maribo

Hanne Maribo is a senior scientist at the SEGES Pig Research Centre, part of the Danish Agriculture & Food Council. Maribo worked in pig research for 30 years. She started her studies in Animal Science and Economics, and received her Phd at the Meat Research Institute.

Can you tell something about your current research?
“During the last ten years I have worked on feed for male pigs to reduce boar taint and increase productivity. Especially the use of fiber sources and pure grains as well as increasing energy and protein levels in the diet.”

How does feed reduce skatole levels?
“The research results show that adding chicory to feed reduces the skatole content of up to approximately 60%. Reducing skatole content by using chicory three days before slaughter compared to two weeks before slaughter gives the same results on the skatole level but is much cheaper. This is due to the fact that the halftime of skatole in fat equals eleven hours. Farms with a delivery section can thus limit the time for which the more expensive feed has to be applied.”

Are there any other feed sources that also affect skatole content?
“Yes, both sugar beet pulp pellets, Jerusalem artichoke and pure grain have a reducing effect on skatole. Using sugar beet for two weeks resulted in a 50% lower skatole content. For pure grain we observed reductions in skatole content of 30%. This is quite remarkable given the already low skatole levels we had in the control group. The principle behind this is that using pure grain reduces tryptophan in the diet, and thereby the substrate for producing skatole.”

And what about the feed cost?
“Using chicory results in 1 euro higher feed cost per pig. For sugar beet and pure grain the increase in feed cost per pig equals €1-2 respectively. When we learn more about the halftime, farmers can use the additives efficiently.”

What would you do if you were a pig farmer who does not castrate the piglets?
“As a pig farmer raising entire male pigs I would use feed with extra energy and protein with split sex rearing. And if there is a penalty on boar taint prevalence, I would use feed with fibres (chicory or sugar beet) or pure grain only during the last few days before slaughter. The age of the slaughter pigs and the breed is also important. Androstenone increases with age/weight and by choosing fathers with a low breeding value for androstenone you can reduce androstenone in the offspring. There are many ways in which skatole levels can be reduced, of which feed is an important factor.”

Read more about feeding techniques on our topic page.