We report the results of Monte Carlo simulations of the suspension of elongated magnetic particles in a nematic liquid crystal (LC) subjected to an external magnetic field. We deal with a model where the LC host is characterized by a set of directors on a spatially fixed three-dimensional lattice. For elastic free energy of the LC matrix, we use the expression based on the Gruhn-Hess lattice model. Ferroparticles are modeled as long line segments interacting with clusters of LC molecules within the unit cell of the lattice through pair potential similar to that in the Lebwohl-Lasher model.