Competitive exclusion in the young bird: challenge models, administration and reciprocal protection

The competitive exclusion (CE) concept has been tested against both non-invasive and invasive salmonella serotypes. Studies with different challenge models indicate that CE treatment is likely to protect the young bird against all serotypes that are capable of intestinal colonization. Spray or ‘droplet’ application of the CE-treatment material was compared with administration in the first drinking water. Both methods gave a similar degree of protection against Salmonella infantis. A study was made to compare protection of newly hatched chicks and turkey poults by the one commercial CE product Broilact ®, and two similar preparations involving intestinal microorganisms from an adult turkey. Each preparation protected both avian species when administered orally prior to challenge, but the degree of protection obtained varied with the type of preparation and its host origin.