Neb. Rev. Stat. § 22-221

No transferred territory under the provisions of sections 22-218 to 22-220 shall be released from the payment of its proportion of the debts of the county from which such territory is transferred. Such proportionate indebtedness from such transferred territory shall be collected by the county to which such territory is transferred, at an equal or greater rate than is levied and collected in the county from which such territory was transferred, such rate to be ascertained by the certificate of the county clerk of the last-named county, and when so collected, to be paid over to the county entitled thereto. The territory so transferred shall not be taxed for the payment of any indebtedness of the county to which the territory is transferred, incurred previous to the transfer.