The European Commission project currently under study is to authorize the use of processed animal proteins (PAP) from poultry in pig feed, and PAP from pigs in poultry feed. Processed animal proteins consist exclusively of by-products from animals slaughtered for human consumption (see box below). There are also plans to allow insect PATs for pigs and poultry.
Avoid prion diseases
The main risk of incorporating poultry and pig protein into animal feed is the transmission and amplification transmissible spongiform encephalopathies (TSEs). These diseases are transmitted by prions, infectious protein particles, which can be spread if products from an infected animal are found in food intended for an animal of the same species. We speak then amplification of the disease.
Current European regulations lay down certain rules to avoid this risk. The first is “non-cannibalism”: it is excluded to give an animal processed animal proteins from its own species. Furthermore, since ruminants are known to be potential carriers of TSEs, such as bovine spongiform encephalopathy or scrapie in sheep and goats, their PAPs are prohibited for use in the feed of all farm animals.
Finally, the draft European text provides, in the event of authorization of poultry PAT in pig feed and vice versa, a effective separation by species of the production sites, from the slaughterhouse to the delivery of feed to the breeder. However, the regulations examined provide that derogations may be granted under the responsibility of the Member States. In fact, in France, as in other European countries, certain slaughterhouses and food production plants concern several species.
The need for strict separation of the food production chain
«The approach of ANSES’s experts was to identify risk situations during which TSEs, known or unknown in the field, might be transmitted, amplified and difficult to control a decade later, like what occurred for bovine spongiform encephalopathy agent in the 80s explains Charlotte Dunoyer, Head of the Animal Health, Food and Welfare Risk Assessment Unit at ANSES. ” This epizootic most certainly developed from a very small number of cases, or even just one, which were then amplified by the intra-species recycling of bovine by-products. »
The main risk of transmission of a TSE would be cross contamination : when animal by-products which are not intended for a species are incidentally found in its diet. These contaminations can take place both before the manufacture of PAPs (at the slaughterhouse and during the collection of by-products), during the manufacture of PAPs or following, in the animal feed production plants that use them. , as well as during the various transports.
THE mixed slaughterhouses, processing several species, are the weakest link in this production chain, the risk of transmission is assessed as the highest there. Indeed, it has been shown experimentally that pigs can develop the disease if they are contaminated by certain ruminant TSEs. This might, for example, be the case if, prior to the manufacture of poultry PAP intended for pig feed, parts of ruminant carcasses were mistakenly mixed with those of poultry. THE minimal risk is achieved when the separation by species of all the sites in the production chain is effective. ANSES therefore recommends strict compliance with this rule.
Insects, a new source of food considered
While insects currently pose little risk of transmitting TSEs, they might, on the other hand, transfer to pigs and poultry pathogenic microorganisms and chemical contaminants. To avoid them, ANSES recommends compliance with certain sanitary rules for breeding insects for animal feed. Thus, the food source for insects must comply with the regulations in force for the feeding of farm animals. This means that they should not be fed waste or excreta, major sources of microbial contamination. Similarly, insects must be completely stripped of the substrate on which they are reared before starting the process of transformation into PAT. A 24-hour fasting period would flush out any contaminants that may be present in the insects’ gut. Finally, some species can accumulate heavy metals such as lead, cadmium or arsenic. The recommendation is therefore to control the presence of these contaminants in insect PAPs.
