Reducing pig odour by changing feed

The scientists' research leader, animal nutritionist Brian Kerr, said the Agricultural Research Service Swine Odor and Manure Management Research Unit is hoping to devise pig feed that will reduce odour-causing ingredients. It is evaluated how factors like nutrition, microbial ecology and pathogens affect pig excretion and how they produce stinking waste.

 

The researchers, managed to control nitrogen-containing compounds such as ammonia by reducing the pigs' protein intake by giving them less soybean meal and balancing their diet with crystalline amino acids.

Kerr said the research showed that for every 1% reduction in dietary crude protein intake, ammonia emissions dropped by 8 to 10%.

Another tactic being examined is changing the type and amount of fibre being fed to pigs. Kerr explained that swine do not digest all of their dietary fibre. Unit studies found that metabolising of this fibre leads to more production of volatile fatty acids that help keep ammonia from being released.

In addition, the unit is trying to understand how sulfur-containing elements could be changed to less stinking smells.