Predicting the digestibility of grass grown for first-cut silage

Meteorological factors influencing the temporal changes of digestibility of grasses in spring and early summer are discussed. Annual observations in England of the digestibility of three grasses are then related to the relevant meteorological variables using two multiple regression analysis methods. The resulting regression relationships are tested on independent data, and finally sets of regression coefficients are recommended for predicting from synoptic meteorological data the weekly progress of digestibility in different areas of England: a simplified set of regression relationships for predicting digestibility values a few days ahead which require forecasts of only temperature in order to be applied operationally is also given.