Neb. Rev. Stat. § 52-1502

Any owner of any stallion, jack or bull within the state may file with the county clerk of any county therein on or before October 1 of each year, a full and complete list of the mares or cows served by such male within such county during that year. Such list shall contain the name of and a brief description of all animals so served, the owners thereof, the terms on which each was bred, and the time when payment thereof becomes due; and it shall be verified by the owner of such stallion, jack or bull, or his lawfully authorized agent.