ENSILED ROLLED OR DRIED BARLEY DRAIN AND DIFFERENT LEVELS OF GRASS-SILAGE AND HAY TO DAIRY-COWS

Ensiled rolled barley grain and dry-stored barley were compared in two 2 x 2 factorial design experiments on individually fed dairy cows. In experiment 1, lactation weeks 4-12, the cows were also offered 1 or 4 kg of hay, and grass silage ad libitum. In experiment 2, lactation we eks 15-26, they were offered 6 or 10 kg DM grass silage complemented w ith barley and protein concentrate in order to equalise energy and pro tein requirements among the blocks. The rumen degradability of barley was determined with the in situ technique. Compared with dry barley, e nsiled barley grain contained less starch and NDF and more sugars. The proportions of DM, N and starch that instantly disappeared in ensiled barley from the nylon bags were 0.62, 0.74 and 0.71, respectively. Co rresponding figures for dry barley were 0.10, 0.04 and 0.04. This resu lted in diverse kinetic parameters, and the calculated effective rumen protein degradability was higher for ensiled grain. However, after 24 h of incubation less DM, N, starch and NDF had disappeared from ensil ed barley than from dry barley. The ensiling of barley grain resulted in a 6% decrease (p less than or equal to 0.05) in milk production (en ergy corrected) in both experiments. During lactation weeks 15-26, the feeding of ensiled barley also lowered the intake of grass silage, es pecially at the high silage level, with a consequent decrease in the i ntake of metabolizable energy. Milk composition was not affected. The level of hay fed did not influence the effect of barley conservation. The higher grass silage level resulted in a lower yield of milk and a higher milk fat content.