Although processed proteins from ruminants are still prohibited for feeding food-producing animals, the possibility of using other by-productsnamely fat, collagen or gelatin, is contemplated.
A very low risk of BSE but an ever-present danger
Since May 24, 2022, France has been classified as “ countries with negligible bovine spongiform encephalopathy (BSE) risk by the World Organization for Animal Health. However, the possibility that a few asymptomatic cases pass through slaughterhouses is not excluded. If the by-products of these animals are used for animal feed after being processed, precautions are necessary to avoid contamination of other animals. Experts from the ANSES working group are particularly attentive to preventing further spread of BSE agents: ” The BSE crisis probably emerged from a very low number of initial cases “, they recall in the notice.
Recommendations to avoid contamination of fats by prions
The limited data available suggests that prions, which induce BSE, do not accumulate in the fat of infected cattle. However, these fats could be contaminated with spinal cord projections. Indeed, if the animal is infected, the latter carries a large quantity of prions. However, when splitting carcasses at the slaughterhouse, the blade passes through the spinal cord. The fats located nearby will thus be exposed via the projections. and could transmit the BSE agent if used for animal feed.
Conversely, the ANSES experts consider that fat obtained from adipose tissue distant from the spine or not exposed to splashes presents a negligible risk. They could thus be used in animal feed. ANSES recommends that studies be conducted to quantify spinal cord projections on adipose tissuetaking into account current slaughterhouse practices.
Moreover, fat removed prior to carcass splitting or when the spinal cord is previously removed presents a negligible risk transmission of BSE. Similarly, in animals under 48 months of age, the spinal cord is highly unlikely to be infectious and contaminate fat. The fat of individuals under four years of age could therefore be used for animal feed.
As for sheep and goats, the working group considers the number of tissues likely to be infected by the agent of scrapie, another TSE, to be too high. He therefore recommends do not use fat from small ruminants.
Collagen and gelatin: a point of vigilance
Bovine collagen and gelatin are produced from the skin and bones of these animals. Their use was authorized at European level in August 2021 for pig and poultry feed. The main point of vigilance noted by the experts concerns the use of bones with a high risk of contamination by prions. The Agency therefore recommends do not use the backbones of cattle older than 30 months to produce collagen and gelatin.
This expertise complements the report on the use of processed animal proteins (PAT) from pigs and poultry published in 2021.