All property subject to valuation for property taxation purposes shall be valued as of January 1 of each tax year, except that livestock shall be valued as of the date and in the manner prescribed under Section 7-36-21 N.M. Stat. Ann. and tangible personal property of construction contractors shall be valued as of the date and in the manner prescribed under Section 1 [7-38-7.1 N.M. Stat. Ann.] of this act.