  We study Quillen's model category structure for homotopy of simplicial
objects in the context of Janelidze, Marki and Tholen's semi-abelian
categories. This model structure exists as soon as the base category A is
regular Mal'tsev and has enough regular projectives; then the fibrations are
the Kan fibrations of simplicial objects in A. When, moreover, A is
semi-abelian, weak equivalences and homology isomorphisms coincide.
