All laws or parts of laws, now in force in this commonwealth, under and by virtue of which taxes for state purposes are levied and assessed upon horses, mares, geldings, mules and cattle, shall be and they are hereby repealed, so far as they give authority to impose state taxes on the same: Provided, That this section shall not take effect until the next meeting of the board of revenue commissioners of this commonwealth.
72 P.S. § 3251