Grazing Winter Wheat with Special Reference to the Mineral Blood Picture

Abstract

In this study chemical analysis showed growing wheat to be an excellent source of calcium, phosphorus, magnesium and protein. Before March 25 the calcium-phosphorus ratio averaged 1.1:1 and after March 25, 0.8:1. When the calcium-phosphorus ratio of the wheat was above 1:1 Hereford calves grazing wheat pasture chose principally bone meal. As the calcium phosphorus ratio became lower than 1:1 they ate ground limestone almost exclusively. Calves receiving bone meal and ground limestone failed to make more gain than those on wheat pasture alone. Calves receiving dry forage in addition to wheat pasture and mineral supplement made slightly larger gains than those receiving no dry feed. Analyses of blood for serum calcium, phosphorus, and magnesium failed to show any definite results that might be correlated with animal disorders resulting from grazing wheat. Blood phosphorus was lower for the calves on wheat pasture than for those in dry lot. Serum magnesium of animals receiving green wheat alone was lower than that of the animals receiving mineral and dry feed. Blood analyses from six animals stricken with symptoms resembling milk fever or grass-tetany while grazing wheat pasture showed that serum calcium and phosphorus were low and serum magnesium high. As a result of treatment with calcium gluconate, serum calcium and phosphorus were increased while serum magnesium was generally lowered. Consideration of Ca:P, Mg:P, Ca:Mg and Ca plus Mg:P ratios in these cases failed to show any uniformity either before or after treatment. This supports the belief that grass-tetany and milk fever may be complex nervous or glandular disturbances instead of simple mineral deficiencies.