Bovine blood biomarkers as a way of processed animal proteins detection in feedingstuffs

The prohibition of using animal by-products in feedingstuffs depends on two factors: their nature defined by the tissue/cell type and the species of origin, and on their destination (pets, fur animals or other farmed animals). Proteomics is particularly well-suited to the purpose of PAPs detection as it is a tissue and species-specific method.

The aim of this study was the identification and the selection of specific peptide biomarkers using tandem mass spectrometry for the detection of bovine blood products and blood meals in animal feed.

Twenty-nine samples of blood meals and blood products (plasma or haemoglobin powder) of porcine, poultry and bovine origin as well as three milk products and two fish meals were analysed using a Q TOF mass spectrometer. Vegetal feed samples adulterated with 1% or 10% of bovine plasma powder, haemoglobin powder or blood meal were also analysed to evaluate the applicability of the method.

Four proteins of interest were highlighted: Alpha-2-macroglobulin, apolipoprotein A-1, serotransferrin and haemoglobin (α and β chains). From these proteins, sixteen peptides were identified as potential bovine blood biomarkers in feedingstuffs. Nine of them could be used for the detection of plasma powder and seven of them for haemoglobin powder or blood meal. The evaluation of these peptides by a search against NCBInr database revealed that some of them could also be used to detect other ruminant bloods such as ovine or caprine ones.

These preliminary results are promising. Efforts are now focused to improve the protocol in order to increase the sensitivity of the method as regards the selected proteins.