Influence of flame roasting and feeding frequency of barley on performance of dairy cows.

In Experiment 1, 24 multiparous cows in early lactation were fed a basal diet for ad libitum intake consisting of 24.3% (DM) corn silage, 25.9% whole crop barley silage, 33.1% alfalfa silage, and 16.7% of a protein supplement. Raw barley grain, or barley flame roasted to reduce its rate of rumen degradation, was fed twice daily or seven times daily. Of the 24 cows offered roasted barley, 3 refused to consume it even after 2 wk. Thus, results are for the 21 cows that consumed raw and roasted barley. Cows fed raw barley seven times ate more DM, OM, NDF, and CP than cows fed raw barley twice daily and also produced more milk, protein, and lactose. Cows fed roasted barley twice daily ate more NDF than those fed raw barley twice daily and also produced more milk, protein, and lactose. No benefit resulted from increasing the feeding frequency of roasted barley from two to seven times daily. Experiment 2, conducted to investigate the apparent unpalatability of roasted barley, showed that cows fed a TMR containing 40% (DM) of the roasted barley used in Experiment 1 consumed less NDF but tended to produce more lactose. Based on results of both experiments, if raw barley is fed alone, it should be fed multiple times per day to maximize production. However, infrequent feeding of roasted barley is an acceptable alternative, if the cows will consume the roasted barley. When barley can be fed multiple times per day or in a TMR, benefits of roasting appear to be negligible.