Commercial Flock. A person having a commercial flock in Maryland shall have the flock tested in accordance with either §A(2) or (3) unless the flock is: Participating in and meets the requirements of the: NPIP's “U.S. Sanitation Monitored” program for egg-type chicken breeding flocks, 9 CFR 145—147, or “Salmonella Enteritidis Monitored Flock Program of Pennsylvania” or an equivalent plan of another state, provided that plan has been approved by the Secretary; Derived immediately from a multiplier breeding flock that has been tested and found negative for Salmonella serotype enteritidis under the procedures outlined in §B; or Derived immediately from a primary breeding flock that has been tested and found negative for Salmonella serotype enteritidis under §C. Environmental Sampling/Serological Test. A person shall allow the Department to: Collect environmental samples from all egg belts, elevators, or both, within caged systems or throughout open floor systems; Culture or biochemically test these samples for the presence of Salmonella serotype enteritidis species; Test, if any flock tests positive to environmental testing, a random sample of 500 birds per house for the presence of Salmonella enteritidis antibodies; and Permanently identify and submit a statistically significant sample of seropositive birds to an official state diagnostic laboratory for pathological examination and culture for Salmonella serotype enteritidis. Blood Testing. A person shall permit the Department to: Test a random sample of 300 birds per house for the presence of Salmonella serotype enteritidis antibodies; and Handle birds testing positive in the manner provided under §A(2)(d). Multiplier Breeding Flock. Except as provided in §B(2), a person having a multiplier breeding flock shall have the flock tested by the Department as follows: At least 300 birds per age group shall be randomly selected and blood tested for the presence of Salmonella serotype enteritidis; The flock shall undergo environmental sampling of nests and litter each month; At least 30 dead in shell embryos shall be tested each 3 months; and Any serological evidence of infection shall be followed with bacteriological examination of a statistically significant sample of reactor birds from each age group and, only if the bacteriology is negative, shall the flock be considered negative. A person owning a multiplier breeding flock is not required to have the flock tested as described in §B(1) if the flock is participating in and meets the requirements of: The NPIP's “U.S. Sanitation Monitored” program for egg-type chicken breeding flocks; or The “Salmonella Enteritidis Monitored Flock Program of Pennsylvania” or an equivalent program of another state, provided that plan has been approved by the Secretary. Primary Breeding Flock. Except as provided in §C(2), a person having a primary breeding flock shall follow the same procedures outlined in §B. Instead of randomly selecting and testing 300 birds per age group as provided under §B(1) for a primary breeding flock a person shall allow the official State agency to randomly select and test the larger of the following two groups: 300 birds per age group; or 1 percent per age group. Effect of Isolating Salmonella Serotype Enteritidis. If Salmonella serotype enteritidis is isolated from a flock in Maryland, a person may distribute, offer for sale, or sell only: Eggs from that flock that: Have been pasteurized or otherwise heat treated to kill Salmonella serotype enteritidis, or Are to be pasteurized, provided the eggs are moved to a plant that the USDA has approved for processing egg products; and Birds or progeny from that flock for slaughter, provided the birds are moved for slaughter to an official establishment to be inspected and either condemned or passed for cooking only.