So where do these ‘beneficial’ bacteria come from? When chicks hatch their digestive tracts are virtually sterile. If raised by a mother hen, they would obtain the beneficial microflora by consuming some of their mother’s fecal mate- rial. This is not possible in artificial incubation and brooding. Probiot- ics are a collection of the normal beneficial microflora that would inhabit a chicken’s digestive tract. By spraying it in the shipping boxes or supplying it in the first feed the chicks receive the ’good’ bacteria that they need to fight off infection by pathogenic bacteria, such as salmonella.