  In the context of a broad class of quenched models, we derive a generalized
differential form of the Kadanoff-Baym (KB) ansatz which relates the out of
equilibrium correlated and spectral Green's functions. This relation holds at
any time both before the quench (when it coincides with the
fluctuation-dissipation theorem) as well as after it. We also examine, in the
context of exactly soluble quenched models, the validity of some of the earlier
alternative extensions of the KB ansatz.
