EFFECTS OF LENGTH OF ACCESS TIME TO FEED AND ALLOTMENT OF HAY ON GRASS-SILAGE INTAKE AND PRODUCTION IN LACTATING DAIRY-COWS

Effects of the length of the time of access to feed (for h or for 8 h) at high (4 kg) or low (2 kg) amounts of hay in silage-based rations were studied for two years. Each year the feeding experiment comprised 56 individually fed cows in a 2 x 2 factorial design. The experiment covered weeks 1-12 of the lactation in year 1 and weeks 1-20 in year 2. The cows were fed unwilted silage ad libitum, restricted amounts of hay and concentrate according to ECM yield. Increasing the access time from 8 h to 24 h increased silage DM, roughage DM and total DM intake (almost-equal-to 6%) in both years. This resulted in increases of ECM yield by 4% and 7% in years 1 and 2, respectively. Increased allotment of hay increased significantly roughage DM intake, in year 2, when the quality of the hay was high, but not in year 1, when it was lower. Total DM intake was also significantly increased, in year 2, when high levels of hay were fed. Restricted feeding time and low level of hay gave the poorest performance. It was concluded that 8 h/day of access to feed was not enough in early lactation.