Neb. Rev. Stat. § 27-614: Neb. Rev. Stat. § 27-614

(1) The judge may, on his own motion or at the suggestion of a party, call witnesses, and all parties are entitled to cross-examine witnesses thus called.

(2) The judge may interrogate witnesses, whether called by himself or by a party.

(3) Objections to the calling of witnesses by the judge or to interrogation by him may be made at the time or at the next available opportunity when the jury is not present.