No slaughterer or packer shall bleed or slaughter any livestock except by a humane method. The following methods are in all instances prohibited:
     (a) Use of a manually operated hammer, sledge or pole-ax as a means of slaughtering any animal or of rendering any animal unconscious in preparation for slaughter.
     (b) Shackling and hoisting or hanging any animal while such animal is conscious, in the positioning of such animal for slaughter.