Digestion and utilization of high moisture barley by lactating dairy cows

Two experiments were conducted to study digestion and utilization of dry and high moisture barley. Dry matter yield of dry barley was 2.99 tonnes/ha in contrast to 3.58 tonnes/ha for high moisture barley. In Experiment 1, 38 cows in early to midlactation were assigned to two diets (40% alfalfa hay; 9.4% supplement and 50.6% barley, DM basis) that differed only in the type of barley fed: diet 1, rolled dry barley, and diet 2, rolled high moisture barley. Although DM intake, milk yield, and 4% FCM were not significantly influenced by diet, cows fed diet 2 had higher milk persistency than those fed diet 1. In Experiment 2, three lactating cows fitted with ruminal and duodenal cannulae were assigned to three dietary treatments in a Latin square design. Diets 1 and 2 were as in Experiment 1, whereas diet 3 contained ground high moisture barley. Digestibility coefficients tended to be lower and duodenal starch percent higher for cows fed diet 3 than those fed diets 1 or 2. No significant dietary differences were observed in ruminal pH, VFA, or ammonia concentrations. Although ensiling and processing influenced the rate and extent of DM and CP degradation in situ, treatment did not influence effective degradability. Results suggest that the feeding value of high moisture barley for lactating cows is equivalent to dry barley on a DM basis.