Studies On Hemorheology And Mineral Elements Of Hoof Deformities In Holstein Dairy Cattle

The purpose of the studies was to provide scientific theories for prevention and curing of hoof deformities in dairy cattle.20 holstein dairy cattle, in Changsha region, were chose as research object. Changes of main hemorheological parameters of hoof deformities and normal hoof in dairy cattle in summer (June) and winter (December) were measured and analyzed systematically. The content of 9 mineral elements (Mn, Zn, Cu, Co, Mg, Fe, Cd, Cr, Ca) in the dairy diets, hair, hoof, milk and whole blood were determined by flame atomic absorption spectrophotometry .The results were as follows:1. In summer, at shear rates of 1S-1, 3S-1, 5S-1, 10S-1, 30S-1, 60S-1 , whole blood viscosity of hoof deformities were higher than those of normal hoof in dairy cattle (P<0. 05). Low-shear blood reductive viscosity of hoof deformities in dairy cattle(47. 85±6. OOmPa. s) was higher (37. 02± 2. 30mPa.s) (P<0. 01) . Packed cell volume of hoof deformities in dairy cattle 0.33±0.02 was higher 0.28±0.05 (P<0. 05). Erythrocyte sedimentation rates of hoof deformities in dairy cattle were faster (P<0. 05).2. In winter, at shear rates of 5S-1, 10S-1, 30S-1, 200S-1, whole blood viscosity of hoof deformities in dairy cattle were higher(P<0. 05). Plasma viscosity of hoof deformities in dairy cattle (2. 56 ± 0. 30mPa. s) was higher than that of normal hoof in dairy cattle (2.27±0. 18mPa. s) (P<0.05). Erythrocyte sedimentation rates of hoof deformities in dairy cattle were faster than that of normal hoof in dairy cattle (P<0.05).3. The content of Cu in the hair of hoof deformities in dairy cattle were higher than those of the control group. The content of Fe, Ca in the hoof ofhoof deformities in dairy cattle decreased, but the content of Cr increased.In the milk of hoof deformities in dairy cattle, the content of Mn were higher. The content of Zn in the whole blood of hoof deformities in dairy cattle increased while the content of Co decreased in contrast with that of the control group.4 The content of Mn, Cr, Cu in the formula feed and the content of Mn, Cu in green grass and straw were elevated. The content of Cu, Cr, Cd exceeded the standard, whereas Ca, Mg was deficient in drinking water.In summer, packed cell volume increased and aggregation of erythrocyte strengthened, which resulted in increasing of whole blood viscosity at low shear rates; In winter, plasma viscosity increased and aggregation of erythrocyte strengthened, which also resulted in increasing of whole blood viscosity. Increasing of whole blood viscosity, strengthening of aggregation of erythrocyte, which caused microcirculatory disturbance in the hoof part of dairy cattle. At the same time, metabolism turbulence of Fe, Ca, Cu, Cr, Co, Zn influenced horn growth normally, decreased horn hardness, in result that hoof became softening, horn wore off abnormally. In addition to supporting huge weight on hoof and unscientific management, which were the factors that formed hoof deformities in holstein dairy cattle.