none673siDecays of beauty baryons to the D0 p h− and Λ+c h− final states (where h indicates a pion or a kaon) are studied using a data sample of pp collisions, corresponding to an integrated luminosity of 1.0 fb^−1, collected by the LHCb detector. The Cabibbo-suppressed decays Λ0b → D0 p K− and Λ0b → Λ+c K− are observed, and their branching fractions are measured with respect to the decays Λ0b → D0 p π− and Λ0b → Λ+c π−. In addition, the first observation is reported of the decay of the neutral beauty-strange baryon Ξ0b to the D0 p K− final state, and a measurement of the Ξ0b mass is performed. Evidence of the Ξ0b → Λ+c K− decay is also reported.openR. Aaij; B. Adeva; M. Adinolfi; C. Adrover; A. Affolder; Z. Ajaltouni; J. Albrecht; F. Aless...