Submitted to: Joint Abstracts of the American Dairy Science and Society of Animal Science
Publication Type: Abstract Only
Publication Acceptance Date: March 15, 2002
Publication Date: June 22, 2002
Citation: Soder, K.J., Stout, W.L., Gburek, W.J., Folmar, G.J. Effect of Soil Type and Fertilization Level on Mineral Concentration of Pasture: Relationship to Ruminant Performance and Health. Joint Abstracts of the American Dairy Science and Society of Animal Science. Journal of Dairy Science. 2002. v. 85(Suppl.1): Abstract p. 386. Technical Abstract: A study was conducted to measure the effects of varying levels of dairy slurry application on mineral content of forages from three soils types. Slurry was applied to orchardgrass (Dactylis glomerata L., cv. Pennlate) using 60 cm diameter drainage lysimeters to measure the direct impact of four levels of slurry (urine and feces) N application (0, 168, 336, 672 kg N/ha/yr) on mineral content of the forage on three soil types (Hagerstown, Hartleton, and Rayne soil types). The results were then related to potential impacts on performance and health of grazing dairy cows. Forage P was not affected by slurry application (mean = 0.46% DM). Forage grown on the Harlteton soil had the highest P content (0.6% DM). Forage K increased with increased slurry (2.50, 2.85, 3.22, and 3.45% DM, respectively), and was lowest for forage grown on the Rayne soil (2.69% DM). Forage Ca decreased with increased slurry (0.59, 0.56, 0.50, and 0.49% DM, respectively) and was not affected by soil type. Forage Mg also decreased with increased slurry (0.25, 0.24, 0.24, and 0.23% DM, respectively), and was highest for the Harlteton soil (0.27% DM). The variable results in mineral content associated with soil type may have, in part, been due to prior soil fertility. The P and Mg levels in all treatments were generally adequate for grazing dairy cows. The K levels were high in relation to NRC recommendations for prepartum dairy cows, which may predispose them to milk fever. The Ca levels were inadequate for lactating dairy cows. Comprehensive forage testing and ration balancing based on individual farm situations is the best strategy to ensure proper mineral nutrition of grazing animals.