Mineral element status of soils, native pastures and cattle blood serum in the mid-altitude of western Ethiopia

Abstract

Despite the crucial role of mineral elements in animal production and health, their status in soil, native pasture and animal body tissues or fluids in the mid-altitude of Ethiopia has had little study. To determine the concentration of mineral elements in soil, native pasture and blood serum of Horro cattle (local zebu), samples were collected from four sites situated within a 30km radius of Bako Research Centre (BRC) at the end of the rainy season and during the following dry season. Mean mineral element concentrations in soil and native pasture in the bottomlands tended to exceed levels in the uplands for almost all investigated elements. Soil Ca, Mg, K, Fe, Mn and Cu concentrations were within the optimum range for active plant growth, but the levels of available Zn and P were below the critical limit. At the upland sites the effect of season on native pasture mineral element concentration was significant only for P (P<0.05) and K (P<0.01). Upland native pasture Zn concentrations in both wet and dry seasons and Cu and P in the dry season were below cattle requirements, but the remainding mineral elements were above or within the recommended range. Except for P, season affected serum mineral element concentrations significantly (P<0.01). There was no significant (P>0.05) difference between male and female cattle for any serum mineral measured. A season x gender interaction was significant (P<0.05) only for serum P. Dry season serum Zn and Mg concentrations in female cattle and dry season serum Cu concentration in both sexes fell below the critical value. The correlation coefficient between soil and native pasture was r = 0.81 for Ca (P<0.05) and r = 87 for Mg (P<0.05). A negative relationship was obtained between wet season soil Mg and serum Mg in male cattle (r = -0.96; P<0.05). A high negative correlation (r = -0.99; P<0.01) was also obtained between native pasture Mg and serum Mg from male cattle in the wet season. Based on the information obtained from soil, native pasture and serum assays, low levels of Zn, P, Cu and Mg in soil and native pasture could potentially limit livestock production in the study area.


Keywords: animal nutrition; communal grazing; Horro cattle; seasonal changes; minerals


African Journal of Range & Forage Science 2002, 19(3): 147-155