  We study resistivity temperature dependence of a three dimensional metamagnet
near the metamagnet phase transition point in the case when magnetic structure
tends to split into regions with high and low magnetization. We show that in
the case of weak pinning the spin relaxation time of domain wall is much larger
than that of the volume spin fluctuations. This opens a temperature range where
resistivity temperature dependence is determined by scattering of conducting
electrons by the domain wall fluctuations. We show that it leads to
quasi-linear low temperature dependence of resistivity.
