Earlier studies at CEDAR established the positive effects on intake and milk production when forages other than grass were incorporated into dairy cows rations. The area of forage maize and its integration in UK dairy rations continues to increase and as a result has generated considerable interest in supplementation of diets based on maize (MS) and grass silage (GS). The aim of the current study was to determine the effect of using starch (S) and fibre (F) based concentrates on feed intake and milk production of Friesian cows offered a forage mixture of MS and GS in a 3:1 DM ratio.

Forty individually fed multiparous Friesian cows were used in a continuous design study. At week 3 of lactation cows were allocated to one of four treatment groups (Table 1), in which all cows were offered ad libitum access to a forage mixture containing on a DM basis 750 g/kg MS and 250 g/kg GS and 10 kg fresh weight/d of either a starch (229 g starch and 58 g NDF kg/DM) or fibre (85 g starch and 124 g NDF/kg DM) based concentrate. Both concentrates contained 237 g CP and 13.1MJ ME/kg DM and were offered twice dairy in equal quantities.