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Digestion in sheep of diets containing naked oats or barley
Author(s) -
Martin Pamela A
Publication year - 1990
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.2740520406
Subject(s) - rumen , digestion (alchemy) , hay , fatty acid , zoology , chemistry , meal , food science , avena , straw , biology , agronomy , biochemistry , fermentation , chromatography
Four sheep fitted with cannulas in the rumen and proximal duodenum were used to compare the digestion of two diets in an experiment conducted according to a two‐period reversal design with 28‐day periods. Chopped hay (400 g day −1 ) was given with either 500 g barley and 120 g soya bean meal day −1 or 500 g naked oats and 100 g soyabean meal day −1 . Digestion in the stomach, duodenal flow and faecal excretion of chemical constituents were measured using chromium‐mordanted straw as a marker. As a consequence of compositional differences between the cereals, daily intakes of neutral detergent fibre (NDF), acid detergent fibre (ADF) and total fatty acids were 331 and 295, 172 and 161, and 12·1 and 36·9 g for the barley and the naked oats diet respectively. Dietary substitution of naked oats for barley reduced ( P < 0.05) the extents to which NDF and ADF were digested in the stomach. There was an associated decrease ( P < 0.05) in the proportion of acetic acid in the rumen volatile fatty acids, and the proportion of propionic acid tended to be increased. Rumen ammonia N concentration was reduced ( P < 0.05). Duodenal passage of total N and non‐ammonia N was increased ( P < 0.001), as was that of total fatty acids ( P < 0.05),when naked oats were given but there were no significant differences between diets in N or total fatty acid digestibilities in the total tract. The results show that dietary substitution of naked oats for barley can alter ruminal digestion through effects that appear to derive from the associated increase in lipid intake.