Feed artificially contaminated with various levels of nalidixic-acid-resistant Salmonella montevideo was fed to newly hatched chicks for 7 days. Cloacal and cecal swabs were obtained from the chicks at 7, 14, and 21 days of age to monitor Salmonella colonization relative to the feed contamination level. In one of three trials, less than one Salmonella montevideo per gram of feed was sufficient to establish colonization in 1-to-7-day-old chicks.