The Department of Agriculture shall enforce the provisions of Section 19501 and is authorized and directed to perform the following duties:

Designate, on or before March 1, 1968, and at such times thereafter as it deems advisable, methods of slaughter and of handling in connection with slaughter, with respect to each species of livestock enumerated in Section 19501, which conform to the provisions of Section 19501. In addition, the department may designate other methods not specifically described in Section 19501. However, nothing in this section shall authorize the department to prohibit any method specifically permitted in Section 19501.