title: Progress in identifying and maintaining salmonella-free commercial chicken breeding flocks. 1. 1967-1969.
mesh_terms: D000818:Animals; D001947:Breeding; D002645:Chickens; D005260:Female; D008297:Male; D010375:Pedigree; D011201:Poultry Diseases / Q000175:diagnosis / Q000382:microbiology / Q000401:mortality / Q000517:prevention & control*; D012475:Salmonella / Q000302:isolation & purification; D012481:Salmonella Infections, Animal / Q000175:diagnosis / Q000401:mortality / Q000517:prevention & control*; D012499:Sanitation; D013997:Time Factors