Proponents of circular agriculture want to use animal waste in livestock feed so as to use as much of the animal protein as possible. This is allowed, but only in what are called ‘food webs’, in which, for example, abattoir waste from pigs is processed into chicken feed, says Leo van Raamsdonk, of Rikilt.
A bone fragment of a chicken, 250 micrometer scale. © Rikilt
In order to prevent the spread of BSE (‘mad cow disease), there has been a ban on using abattoir waste from cows in livestock feed in Europe since 2001. The EU placed restrictions on the processing of other animal waste flows too, including meat waste, skin and bones – all of which contain valuable proteins. Proponents of circular agriculture want this ‘bone meal’ to be brought back into use as livestock feed, and therefore want the EU to relax the rules. It is important to keep a close eye on food safety, though, says Van Raamsdonk of Rikilt.
‘Using waste from ruminants in livestock feed is, and will remain, strictly forbidden. There is no support for relaxing those rules, because no one wants to have 180,000 mad cows again, as we did in 2000. The point is that the prions that cause mad cow disease accumulate in the animals’ brains animals over many years. Prion diseases have now been found in deer, reindeer and dromedaries. So you don’t want to bring waste products from ruminants back into the food chain.’
There is more scope for using waste from other animals, though, adds Van Raamsdonk. ‘The EU currently bans the use of pig and poultry waste in feeds. Since 2002, the EU has labelled this cannibalism: animals should not eat members of their own species.’
Bone meal from pigs and poultry may only be used in feed for domestic pets and fish. Van Raamsdonk thinks this rule could be relaxed. ‘The EU is working on that. In the new proposal, pig waste products may be processed into poultry feed. Then the EU still observes the cannibalism ban, but more animal waste products can be processed into livestock feed.’
These EU rules have consequences for the design of the new circular agriculture, thinks Van Raamsdonk. ‘Waste from production chain A – pigs – should be supplied to production chain B – poultry – while waste products from B are supplied to A or C – fish farming. Then you create food webs, in which waste products are moved around via a whole range of different processing methods.’