In vitro ruminal degradability of cereal grain starch

Abstract

An in vitro method was used to determine ruminal degradability of starch (IVRDS) in a set of cereal grains. The set included 9 feed samples, including 2 samples of ground wheat, 2 samples of wheat treated with sodium hydroxide, ground barley, barley treated with sodium hydroxide, 2 samples of ground oats and ground maize. Ruminal degradability of starch was assayed by the feed fermentation for 2, 4, 6, 16 and 24 hours. A significant difference in starch degradability was found between treated and untreated ground samples after 2-hour fermentation (13.73 ± 3.12 vs. 32.77 ± 8.17; P < 0.001), 4-hour fermentation (33.44 ± 7.31 vs. 60.30 ± 16.71; P < 0.001) and 6-hour fermentation (42.63 ± 7.13 vs. 74.20 ± 6.38; P < 0.001). On the basis of the rate of ruminal degradability of starch the order of cereal grains was as follows (from the highest to the lowest value): ground oats, ground wheat, ground barley, ground maize, wheat and barley treated with sodium hydroxide.