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The Pig Toilet

Special thanks to Eyes on Animals - Lesley Moffat

In Kees' pigsty, some of the piglets have learnt to pee and poo in separate corners of the pen. The urine can be used directly as an organic fertilizer substitute, but even better is the lack of ammonia emissions. Ammonia is only produced when the urine and faeces come into contact with each other. The faeces-bacteria contain an enzyme called urease which transforms the urea present in the urine into ammonia (NH3). This nitrogen-hydrogen compound does not only cause a bad smell, it also dissipates the valuable nitrogen present as urea into nitrogen-gas, one of the most aggressive greenhouse-gases.

It just so happens that pigs are naturally trained animals. They prefer to poo and pee away from the nest. Pigs are also very smart, and trainable. In 2012, Kees started testing his theory with three pigs, to see if he could train them to poo and pee in different places. He rewarded the pigs with sour sweets, lemon drops. Pigs love the sweet-sour flavour combination, and they don't mind a good crunch either. After five days of sitting by the pen, Kees had trained his first pigs completely. He patented his find in 2015, and since 2018 has set up further tests on a larger scale at his farm.

Advantages of the Pig Toilet


Airwashing systems are used in intensive livestock farming to reduce the output of polluting gases. With the Pig Toilet, the need for pricey air washing systems will reduce massively due to the huge drop in ammonia. This is great news for the environment.

Secondly, all pigs can walk around in clean air and clean pens without the need for floors to be slatted.

A third important advantage is the pure urine-fraction that is easily collected separately. Using this as fertilizer in arable farming provides a major environmental benefit and an important contribution to the realization of circular agriculture. The solid faeces can be composted together with leaves to improve the humus content of the soil. All in all, a win-win-win-win situation.

Varkenstoilet foto Ronald.jpeg
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