In order to carry out the provisions of ORS § 596.020, the State Department of Agriculture may require such testing, treating and examining of livestock sold, traded, exchanged or handled at or through any stockyard as in its judgment may be necessary to prevent the spread of brucellosis, tuberculosis or paratuberculosis, hog cholera and other infectious, contagious or communicable diseases among the livestock of this state. [1957 c.390 § 20; 1959 c.63 § 7]