9 C.F.R. § 147.17 Laboratory procedure recommended for the bacteriological examination of cull chicks for salmonella.
Title 9 - Animals and Animal Products
The laboratory procedure described in this section is recommended for the bacteriological examination of cull chicks from egg-type and meat-type chicken flocks and waterfowl, exhibition poultry, and game bird flocks for salmonella. (a) From 25 randomly selected 1- to 5-day-old chicks that have not been placed in a brooding house, prepare 5 organ pools, 5 yolk pools, and 5 intestinal tissue pools as follows: (1) Organ pool: From each of five chicks, composite and mince 1- to 2-gram samples of heart, lung, liver, and spleen tissues and the proximal wall of the bursa of Fabricius. (2) Yolk pool: From each of five chicks, composite and mince 1- to 2-gram samples of the unabsorbed yolk sac or, if the yolk sac is essentially absent, the entire yolk stalk remnant. (3) Intestinal pool: From each of five chicks, composite and mince approximately 0.5 cm2 sections of the crop wall and 5-mm-long sections of the duodenum, cecum, and ileocecal junction. (b) Transfer each pool to tetrathionate selective enrichment broth (Hajna or Mueller-Kauffmann) at a ratio of 1 part tissue pool to 10 parts broth. (c) Repeat the steps in paragraphs (a) and (b) of this section for each five-chick group until all 25 chicks have been examined, producing a total of 15 pools (5 organ, 5 yolk, and 5 intestinal). (d) Culture the 15 tetrathionate pools as outlined for selective enrichment in illustration 2 of §147.11. Incubate the organ and yolk pools for 24 hours at 37 °C and the intestinal pools at 41.5 °C. Plate as described in illustration 2 of §147.11 and examine after both 24 and 48 hours of incubation. Confirm suspect colonies as described. Further culture all salmonella-negative tetrathionate broths by delayed secondary enrichment procedures described for environmental, organ, and intestinal samples in illustration 2 of §147.11. A colony lift assay may also be utilized as a supplement to TSI and LI agar picks of suspect colonies. [61 FR 11525, Mar. 21, 1996]
Title 9: Animals and Animal Products
PART 147—AUXILIARY PROVISIONS ON NATIONAL POULTRY IMPROVEMENT PLAN
Subpart B—Bacteriological Examination Procedure
§ 147.17 Laboratory procedure recommended for the bacteriological examination of cull chicks for salmonella.
