Effects of morphological fractions on estimated milk yields in forage maize depending on growing site and plant maturity

This study was undertaken to determine the effects of the morphological fractions of forage maize for milk production as predicted by the spread sheet model called MILK 2006. The plants were harvested at increasing maturities at three different sites in Sweden and separated into stems, leaves, kernels and cobs. Chemical and in vitro analyses of the plant fractions as specified in the MILK 2006 model for predicting estimated milk yields Milk Mg-1 dry matter (DM) and Milk ha(-1) were undertaken. Partial least squares regression analysis was used to evaluate the impact of the proportions and qualities of the fractions on Milk Mg-1 DM and Milk ha(-1). Estimated milk yields could not be predicted based on the proportions of the fractions and their nutritional values. The most important parameters for determining Milk ha(-1) was the DM yield, and for the estimated Milk Mg-1 were the concentrations of starch and the fibre digestibility of the whole crop.