n the last years probiotics have constantly increased in importance and aroused growing interest in animal nutrition. Processing of feed has become more and more aggressive and these tough feed manufacturing conditions, aimed to reduce the microbial charge by potential pathogens such as Salmonella and E. coli, also lead to the elimination of the lactic acid bacteria, which are beneficial for the host animal. It is therefore important to add to the feed an adequate amount of live lactic acid bacteria which, once in the upper part of the intestine, can positively affect the intestinal microbial balance of the animals. In the EU the ban of the antibiotic growth promoters as feed additives has also contributed to this new trend. The application of probiotics in animal nutrition represents nowadays a modern and natural way to improve the zootechnical performances as well as the health and welfare of farm animals.