PROBIOTICS IN POULTRY - MODES OF ACTION

This paper reviews recent advances on the use and mode of action of pr obiotics (direct-fed microbials) in poultry. The addition of probiotic s to the diet has been found to improve growth performance and feed co nversion in broilers, and egg mass, egg weight and egg size in layers. The mode of action of probiotics in poultry includes (i) maintaining normal intestinal microflora by competitive exclusion and antagonism; (ii) altering metabolism by increasing digestive enzyme activity and d ecreasing bacterial enzyme activity and ammonia production; (iii) impr oving feed intake and digestion; and (iv) neutralizing enterotoxins an d stimulating the immune system.