We present an investigation of the magnetic properties of metallic La_0.75Sr_0.25MnO₃/LaNiO₃ multilayers. We have deduced that the free energy of the structures is mainly driven by the magnetic anisotropies of the La_0.75Sr_0.25MnO₃ layers. We have proved the existence of a magnetocrystalline cubic anisotropy, whose easy axes are oriented in the <1 1 0> directions and a substrate-induced in-plane uniaxial anisotropy that favours a (0 1 0) orientation of the magnetization. We have also shown that the magnetic layers are ferromagnetically coupled for LaNiO₃ spacers thinner than 2 nm. For thicker spacers, the coupling strength oscillates with increasing LaNiO₃ thickness.