§ 172-b. Enforcement of article. The state department of agriculture and markets shall enforce the provisions of this article, and it is hereby authorized and empowered to approve and register such brands and labels intended for use under the provisions of this article as may be submitted to it for that purpose and as may in its judgment conform to the requirements of this article; provided, however, that in any prosecution under this article the fact that any brand or label involved in said prosecution has not been submitted to such board for approval, or if submitted, has not been approved by it, shall be immaterial.