The magnetoacoustic SAW interaction has been experimentally investigated for yttrium-iron garnet films placed on gallium gadolinium garnet substrates. In this paper, we propose a new approach to the analysis of hysteresis dependencies which consist of two branches for different directions of magnetic field variation. For each of the branches, even and odd portions were separated. The even portions were shown to be related to magnetostriction and the odd ones to DeltaE-effect and magnetostriction linearized internal magnetic field of domains.