Salmonella pullorum in Turkeys-Experimental Testing in Natural Infection.

IN ALBERTA, a number of factors influence the choice of pullorum testing techniques for turkeys. These include: (1) great distance between flocks; (2) subzero weather at the time of testing; (3) expense of travelling and personnel; (4) the low incidence of pullorum infection in poults; and (5) the difference of opinion indicated in the scientific literature about the relative efficiency of the tube agglutination, rapid serum plate and whole blood tests for the detection of pullorum carriers. In an effort to clarify the fifth point, experimental testing of 20 naturally infected turkey poults was conducted and a brief review of the available literature on pullorum testing was made. L. D. Bushnell (3) reported that the pullorum tube agglutination test in 1:25 dilution was more satisfactory than the whole blood test and the rapid serum plate test, and that the rapid serum plate test, although insufficiently selective, was better than the whole blood stained antigen test. Gauger (7), reporting on tests made on 30 turkeys naturally infected and 17 turkeys artificially infected with Salmonella pullorum, found a very close agreement between the rapid whole blood K antigen and tube agglutination tests when the tube test titre was completed at agglutination in 1:25 dilution or higher. Corpron et al. (5) working with 20 mature turkeys, found the tube agglutination test to be sensitive and more consistent in reaction than the whole blood plate agglutination test for the detection of agglutinins in the serum of turkeys artificially infected with S. pullorum. They also reported that the tube test gave positive reactions earlier. After the height of the titre had passed, the tube test also revealed positive sera which were negative to the whole blood antigens. Garland et al. found that both the tube test, with complete agglutination at 1:25 dilution and the whole blood test with turkey Redigen, compared favourably for detecting carriers of S. pullorum. K antigen proved slightly less sensitive than turkey Redigen for detecting S. pullorum carriers. Carpenter et al. (4) reported the whole blood test to be satisfactory only during infection and egg laying periods. Gwatkin (8) found an agreement between the whole blood and the tube tests of 85.7 per cent and 84.3 per cent with 1:25 and 1:50 dilutions of the tube test. This was with 150 poults infected artificially and by contact. Gwatkin and Dzenis (9) found that the agglutination tests with whole blood and the tube methods showed a disagreement of 10 per cent on total reactions in turkeys artificially infected with regular variant and mixed form cultures of S. pullorum. The same workers (10) found that in turkeys artificially infected with single and multiple oral doses of the