Nutrition of grazing cattle. 2. Estimation of phosphorus and calcium in pasture selected by grazing cattle

Abstract

Linear regressions of phosphorus in pasture samples representative of pasture selectively grazed by cattle on phosphorus in organic-matter faeces are developed for six pasture types. A linear regression is calculated for the six pasture types. Estimates of phosphorus percentage from this regression in feeds fed to stalled cattle are compared with analytical values of phosphorus percentage in these feeds. Agreement is satisfactory. Regressions of calcium in selectively grazed pasture on calcium in organic-matter faeces are developed. The effect of calcium in drinking water is an appreciable source of error in the regression of calcium in pasture on calcium in organic-matter faeces. The accuracy of estimates from regression of phosphorus and calcium in selectively grazed pasture is not increased by including other variables in multiple regression analysis.