Flow resistance of an aq. suspension of hay particles (up to 11% by volume) in a pipeline was studied. The apparent viscosity of the suspensions decreased with the increasing the shearing rate and solid phase content. The flow resistance increased with increasing volume flow and decreasing solid phase content. The Ostwald-de Waele equation described well the flow of low concd. suspensions while the Herschel-Bulkley equation was the best for describing the flow of suspensions with high concn. of solid phase.