(a) Blood test 300 birds per age group pursuant to the procedures set forth in section 57.8(a) of this Part.

(b) Culture 60 birds according to the procedures set forth in section 57.8(c) of this Part.

(c) If flocks are negative upon organ culture reevaluate the flocks by retesting as provided in subdivisions (a) and (b) of this section. If organ cultures continue to be negative, flocks shall revert to negative status, provided that every three months for the remaining productive life of the flocks. No additional birds shall be added to the houses until the houses have been cleaned and disinfected and their environments have been tested pursuant to the procedures set forth in section 57.8(b) of this Part and found negative for Salmonella enteritidis.