Nutrient contents for supplements removed are estimated as the pasture nutrient content times a maturity factor. The maturity factor is an estimate of the decrease in plant nutrient contents as pastures become more mature. Typically, as pastures mature, lignin content (stalks, seed heads, etc) increase and plant nutrient contents decrease. The maturity factor varies for each nutrient. Baleage and silage are assumed to have the same maturity, whereas hay has a lower maturity factor, with values for N of 0.86 for baleage and silage, and 0.6 for hay. Note that the model requires the nutrient content of the removed supplements. Supplements fed, particularly average and poor quality supplements, can have considerable lower nutrient contents.