The use of feed additives is not the same in all parts of the world. Some are still used to cover up bad quality grain, but more and more feed additives are becoming technically advanced ingredients. And some even have hidden, beneficial side effects.Typical feed additives include vitamins, trace elements, yeast, enzymes, plant extracts and antioxidants. The use and effects of all these individual ones have been studied extensively. But do we know everything about these additives yet?Enzymes for example. This is a group of feed additives that is used on a large scale, everywhere around the world. The last few years, more research is being conducted in the use and dosage rates of enzymes. Their know effects include unlocking certain undigestible ingredients or breaking down long protein or sugar chains in raw materials. But over-supplementing of the enzyme phytase for example can have beneficial effects in terms of animal health, and is already been put into practice at some farms. Another great example of new insights on well-known products is the research work from Christophe Courtin and his team from Leuven University in Belgium also showed other ‘hidden’ beneficial effects of the enzyme xylanase. The arabinoxylan oligosaccharides (AXOS) has a prebiotic effect , which has not been known before. AXOS is a degradable product that is released when the enzyme xylanase degrades the NSP arabinoxylan (AX), present in the wheat bran.“AXOS is a pool of molecules that end up as degradation products of the effect of xylanase and they meet the criteria set for prebiotics”, explained Courtin at a recent enzyme symposium. A prebiotic has to be non-digestible, resistant to gastric acidity, fermented by colon microbiota and stimulate the gut bacteria in a selective way. “AXOS meets all these criteria”, the Belgium researcher said. It can therefore be beneficial for poultry to prevent colonisation of Salmonella in the gut.It is interesting that well known feed additives, such as enzymes, are used more and more for different purposes and can therefore be even more efficient and cost-effective than previously thought. It is almost as if we are entering an era with a new types of feed additives: the better versions of the old ones. I also think that nowadays nutritionists and farmers are asking for more technically advanced feed additives that have proven their benefits and are more focused on gut health and immunity enhancing effects. In other words, additives that keep the animals healthy in an antibiotic-free farm. And moreover, feed additives are only used when they also can be a profit to the farmer. This also includes additives that can enhance the end-product and can therefore be sold as a premium or niche product.  Benefiting the animal without extra savings is not enough. The multiple benefits of some feed additives is therefore very beneficial and welcome.I wonder if the dosage rates of certain other feed additives, such as aromatic plants and spices, yeast or certain vitamins, will also be updated as soon as research shows that these ingredients also show secret extra benefits. And I am not even talking about the interaction of certain feed additives that can also unlock certain extra effects in the animal. Research on the benefits and the best way to use certain feed additives will never stop I guess.