Digestibility of whole barley and oat grains by cattle of different ages

Abstract

ABSTRACT1. Three trials were conducted to investigate in cattle of different ages the digestibility of whole barley and whole oat grains in diets with approximately a 1:1 ratio of hay to concentrates. The cattle used were four 17-month-old steers in Trial 1; four non-lactating cows in Trial 2; and six heifers at 7, 10, 13 and 16 months of age in Trial 3. 2. Steers and cows completely digested the starch in the rolled cereals and the steers digested more of the starch of whole barley than the cows. The digestibility of starch in whole oats was high (0·72) and similar in both types of cattle.3. The heifers when 7 months of age had the highest coefficients of starch digestibility for both whole barley and whole oats (0·62 and 0·83 respectively). Digestibility of starch declined with age, but this effect was masked by variations within and between animals at different ages. It is concluded that barley should be rolled before feeding but with oats the benefits from rolling are likely to be small and possibly only worth while when given to adult cattle.