Bacillary white diarrhoea : results of testing a breeding flock / by T. Dalling, J.H. Maosn, and W.S, Gordon.

  • Dalling, Thomas.
Date:
[1927?]
Catalogue details

Licence: In copyright

Credit: Bacillary white diarrhoea : results of testing a breeding flock / by T. Dalling, J.H. Maosn, and W.S, Gordon. Source: Wellcome Collection.

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    A. The results were as follows: I.D. 4 Agg • 4 I.D. I.D. 4 Agg. 4 82 402 152 9 The hens were now divided into three groups, {&) those reacting to doth tests 4 those reacting to agglutination test alone (91 birds), (b) those negative to both tests (402 birds), (c) those reacting to intradermic but not to agglutination tests (152 birds)* Reason, eggs laid by negative For the remainder of the breeding reacting hens (group b) were used; no B.W.D. resulted. Eighty eggs laid by hens of group (c) were incubated; no B.W.D. was found. Twelve hens from group (a), i.e., reactors to both tests, were sent to the laboratory. They were mated with a non-agglutinator cockerel and their eggs were collected and hatched out under hens. The following results were got: Chicks Chicks Eggs. hatched. B*W II 3 1 11 7 r> 13 10 2 13 9 1 13 6 2 13 5 2 74 40 10 died T\ «u. One hen died. The ovary showed typical 3. 3. pullorum was cultivated from them. 3. lesions and Discussion. This work confirms the view held by American workers and record- ed in the report of the Proceedings of the United States Livestock Sanitary Association (1), that the agglutination test is valuable as a means of removing 3. pullorum carrier fowls from a breeding flock. We regard complete agglutination at a serum titre of 1 in 40 as a positive reaction, Whether 1 in 10, as used in some American labor¬ atories, or 1 in 100, is the best dilution to use in large scale eradi¬ cation work does not appear yet to be fully settled. It is probable that the intradermic method of testing may also be useful. Results of testing the above flock, would indicate that the intradermic method of testing condemns a greater percentage of hens than