a1 Houghton Poultry Research Station, Houghton, Huntingdon, Cambs. PEI 7 2DA
The continuous administration of food containing 10 mg/kg of avoparcin to groups of 28 chickens in contact with five chickens experimentally infected with a nalidixic acid-resistant (nalr) mutant of a salmonella strain strongly favoured the colonization of their alimentary tracts with salmonella organisms. Bacitracin, 10 mg/kg, either had no effect or only slightly favoured salmonella colonization and sodium arsenilate usually hindered it.
(Received June 02 1979)