304 HOG CHOLEKA 



for marketing under the conditions set forth in para- 

 graph 1 of this section. If the test is again found "un- 

 satisfactory," as defined in 1 and 2, rule C, paragraph 

 2, section 5, of this regulation, the serum shall not be 

 marketed unless and until it is either concentrated, re- 

 fined, and tested in a manner approved by the chief of 

 bureau, or mixed with other serum and tested as pro- 

 vided in section 7 of this regulation. 



SECTIONS. Paragraph 1 (c) . Anti-hog-cholera serum 

 which has been found "unsatisfactory for purity" may 

 again be tested for purity upon 8 pigs, provided each 

 pig receives a single injection in the axillary space of at 

 least 20 c. c. of the product to be tested. Immune pigs 

 may be used for testing the purity of anti-hog-cholera 

 serum if desired. The pigs used should be held under 

 the supervision of a bureau employee for at least 15 

 days. 



SECTION 11. Paragraph 3. Should the return date of 

 any batch of anti-hog-cholera serum expire before the 

 serum is used, the serum should be retested, and if found 

 satisfactory as defined in rule D, paragraph 2, section 5, 

 of this regulation, the return date may be extended one 

 year from the date of retest. 



REGULATION 20. BACTERINS, VACCINES, TOXINS, ETC. 



SECTION 2. Paragraph 1. The return date on the 

 trade labels of blackleg vaccine prepared from attenu- 

 ated B. chauveaui, or blackleg muscle virus, shall be a 

 date not more than one and one-half years later than 

 the date on which the preparation of the product is 

 completed, without regard to the filling of final con- 

 tainers. 



