T. Penev, Z. Manolov, I. Borissov, V. Dimova, Tch. Miteva, Y. Mitev, V. Kirov
Abstract. The investigation was performed in three Bulgarian free-stall cattle farms with different flooring types. The floor of farm A was covered with two rubber mat types, with and without abrasion lining. At the other two farms, floors were made of grooved concrete which was used for 6 years (farm B) and for 4 years (farm C). The purpose of the investigation was to determine the friction coefficients on the different floorings with tribometer described by Phillips and Morris (2000) and the influence of some factors as usage period, presence of manure and water on the floor. The coefficient of static friction of dry floors at the studied farms varied from 0.46 on the concrete floor at farm B to 0.59 on the rubber floor with abrasion lining. It indicated that dry floors at the surveyed farms provided good safety for standing animals. The dynamic friction of dry floors was the lowest at farm B – 0.44, and the highest on the rubber floor with abrasion lining at farm 1 – 0.56. When water was spilled on the floor, static friction coefficients of all studied floorings decreased except for the rubber floor with abrasion lining, where it increased up to 0.61. The dynamic friction coefficients were lower when all floors were wet. The lowest dynamic friction coefficient was determined on the floor at farm B – 0.39, which is under the critical minimum. This was attributed to its longer usage and thus, its wearing and smoothing. Static friction coefficients on manure-covered floors varied from 0.4 to 0.49. The lowest dynamic friction coefficient (0.36) was measured on the floor at farm B, and the highest (0.46) – on the rubber floor with abrasion lining, farm A.