Neb. Rev. Stat. §§ 52-1504
Every such lienor may foreclose such lien by delivering to any sheriff or constable a true copy of such lien certified by the clerk of the county, together with an affidavit of the lienor or any agent or attorney having knowledge of the facts, stating the amount due and unpaid on such lien, with direction to such officer to foreclose such lien. Thereupon such officer shall seize such mare or cow and its offspring and sell the same in the manner provided by law for the sale of personal property on execution, and retain the principal and interest and expenses of such seizure and sale, and the overplus, if any, pay over to the owner of such mare or cow, or deposit the same for him with the county clerk, and make and file due return thereof with the county clerk.
Neb. Rev. Stat. §§ 52-1504