(1) Required laboratory examination for the presence of unwholesome mammary secretions, whether an infectious, physiological, or environmental origin, must be made on all raw milk samples at least twice each 6 months. Samples shall be analyzed at the department of livestock's diagnostic laboratory or at a laboratory approved by the department administrator.

(2) When a herd milk sample exceeds any of the following screening test results: California mastitis test -- weak positive (CMT1+) ; catalase test -- 30 percent oxygen; modified whiteside test -- positive (1+) ; Wisconsin mastitis test -- WMT value of 28; a somatic cell count using the direct microscopic clump count method or equivalent, or the electronic method must be made on that sample. The results of the somatic cell direct count are the official results.

(3) Whenever the somatic cell count indicates the presence of 1,500,000 or more somatic cells per ml., the following procedures must be applied:

(a) A notice sent to the producer warning him of the excessive somatic cell count;

(b) Following the second consecutive high somatic cell count, a milking time inspection made by a representative of the department.

(c) A third milk sample taken after a lapse of 3 days and within 14 days of the inspection required under (3) (b) above. If this sample also indicates a high somatic cell count, the department must request the producer to obtain expert advice on the correction of his problem.