Milk yield and composition of dairy cows fed concentrate based on naked oats

A 1.5-yr study was designed to determine the effects of feeding isonitrogen ous and isoenergetic concentrates based on naked oats, corn, or a mixture ( 50: 50 on as-fed basis) of naked oats and corn on milk yield and compositio n. In vitro dry matter (DM) digestibility and ruminal degradabilities of DM , N, and starch of naked oats were compared with those of covered oats. Twe nty-seven multiparous Holstein cows were blocked by similar calving date an d assigned to 9 replicates. All cows were fed a mixture of grass silage, pr otein supplement, concentrate, and a vitamin and mineral mix for ad Libitum intake. Treatment diets were fed from 3 to 36 wk of lactation. Milk yield and composition, yield of 4% fat-corrected milk, and yield of protein and f at were similar among treatments. Ruminal effective degradabilities of DM w ere higher for naked oats than for covered oats, but the ruminal degradabil ities of crude protein and starch were similar. The rapidly degradable fi a ctions of DM, crude protein, and starch were greater for naked than covered oats; the potentially degradable fractions were less. In vitro DM digestib ility of naked oats was higher than was that of covered oats. Naked oats ma y be a good alternative to corn for milk yield.