Participating flocks, and the eggs and baby poultry produced from them, that have met the respective requirements specified in this section may be designated by the following terms and their corresponding designs illustrated in § 145.10.

(a) U.S. Pullorum-Typhoid Clean. A flock in which freedom from pullorum and typhoid has been demonstrated to the Official State Agency under the criteria in paragraph (a)(1) or (a)(2) of this section. (See § 145.14(a) relating to the official blood test for pullorum-typhoid where applicable.)

(1) It has been officially blood tested within the past 12 months with either no reactors or reactors that, upon further bacteriological examination conducted in accordance with part 147 of this subchapter, fail to isolate S. pullorum or S. gallinarum.

(2) It is a breeding flock that meets one of the following criteria:

(i)(A) It is a multiplier or primary breeding flock of fewer than 300 birds in which a sample of 10 percent of the birds in a flock or at least 1 bird from each pen, whichever is more, has been officially tested for pullorum-typhoid within the past 12 months with either no reactors or reactors that, upon further bacteriological examination conducted in accordance with part 147 of this subchapter, fail to isolate S. pullorum or S. gallinarum; or

(B) It is a multiplier or primary breeding flock of 300 birds or more in which a sample of a minimum of 30 birds has been officially tested for pullorum-typhoid within the past 12 months with either no reactors or reactors that, upon further bacteriological examination conducted in accordance with part 147 of this subchapter, fail to isolate S. pullorum or S. gallinarum.

(ii) It is a flock that has already been designated U.S. Pullorum-Typhoid Clean and uses a subsequent bacteriological examination monitoring program of hatcher debris or eggs for ostriches, emus, rheas, or cassowaries acceptable to the Official State Agency and approved by the Service in lieu of annual blood testing.

(iii) It is a multiplier breeding flock located in a State that has been deemed to be a U.S. Pullorum-Typhoid Clean State for the past 3 years, and during which time no isolation of pullorum or typhoid has been made that can be traced to a source in that State, that uses a bacteriological examination monitoring program of hatcher debris or eggs or a serological examination monitoring program acceptable to the Official State Agency and approved by the Service in lieu of annual blood testing.

(b) U.S. Avian Influenza Clean. This program is intended to be the basis from which the breeding-hatchery industry may conduct a program for the prevention and control of avian influenza. It is intended to determine the presence of avian influenza in all ostrich, emu, rhea, and cassowary breeding flocks through routine serological surveillance of each participating breeding flock. Acceptable tests include antigen and antibody detection tests, as approved by the Official State Agency. A flock, and the hatching eggs and chicks produced from it, will qualify for this classification when the Official State Agency determines that it has met one of the following requirements:

(1) It is a primary breeding flock in which 10 percent of the flock, up to a maximum of 30 birds, has been tested negative for type A influenza virus with all pens represented equally and when the tested birds are more than 4 months of age. Positive samples shall be further tested by an authorized laboratory. To retain this classification:

(i) A sample of at least 30 birds must be tested negative at intervals of 180 days, or

(ii) A sample of less than 10 percent of the birds, up to a maximum of 30 birds, may be tested and found to be negative at any one time if all pens are equally represented and a total of 30 birds are tested within each 180-day period.

(2) It is a multiplier breeding flock in which a minimum of 30 birds has been tested negative to type A influenza virus with all pens represented equally and when the tested birds are more than 4 months of age. Positive samples shall be further tested by an authorized laboratory. To retain this classification:

(i) A sample of at least 30 birds must be tested negative at intervals of 180 days, or

(ii) A sample of at least 10 percent of birds from each pen with all pens being represented must be tested negative at intervals of 180 days; or

(iii) A sample of less than 10 percent of the birds may be tested, and found to be negative, at any one time if all pens are equally represented and a total of 10 percent of the birds are tested within each 180-day period.