No matter what regulations may dictate it’s unrealistic to expect complete elimination of salmonella from animal feed, especially at the point when the animal actually consumes the feed. Nevertheless, it is always best to shoot for the stars than hit the ditch!
But, if we cannot achieve a zero-tolerance level for salmonella in animal feed at least with current technology and know-how), we can at least drastically reduce it to a point where it does not pose a significant threat to animals or humans. From a nutritionist's point of view, there are indeed a few practical things we can implement immediately to help reduce salmonella in animal feed.
We can reduce or avoid ingredients that are known to harbor high(er) levels of salmonella, especially if they are of suspect quality and (or) without microbiological guarantees. Such are fish meal, meat meal, blood-derived products, and some milk products.
Certain organic acids used at the correct dosage are known to be quite effective against salmonella in animal feed. There is a great amount of literature on this topic, but the most important aspect is that the required dosage is rather higher than currently practiced (for cost saving reasons).
Steam heating, pelleting, extrusion, and expansion, all can reduce the salmonella load in ingredients and complete feeds. However, the required temperatures to achieve zero salmonella concentrations usually end up being destructive to the nutritive value of the heated feedstuff.
Salmonella is bound to reenter the animal feed system at some point, such as through an unclean truck or a half-filled silo. To this end, it is best to pay attention to what happens to feed after it leaves the feed plant. In general, the shorter the route and time from production to consumption reduces the chance for any significant salmonella growth to occur.