Neb. Rev. Stat. §§ 52-1501
Every owner, lessee, agent or manager of any stallion, jack or bull shall have a lien upon any mare and her colt or upon any cow and her calf served by such stallion, jack or bull for the full amount of the reasonable or agreed value or price of such service. Every such owner, lessee, agent or manager of such stallion, jack or bull desiring to perfect a lien upon any mare and her colt, or upon any cow and her calf, shall at any time after breeding any such animal to any such male, file with the county clerk of the county a verified notice of lien describing such animal with reasonable certainty, giving the name of the owner and his place of residence if known, and the name and residence of the person having the possession of such animal, the location of such animal, the terms of payment for such service, the amount thereof, the name of the male, the date of service, and the time or event when the same shall become due and payable and such other matters as to make the same more certain. Thereafter such lienor shall have a first lien upon such animal or animals described therein, and their offspring as soon as the same may be born, subject, however, to the lien of record of any prior mortgage in good faith.
Neb. Rev. Stat. §§ 52-1501