AVAILABILITIES OF AMINO ACIDS IN BARLEY AND WHEAT FOR GROWING PIGS

Abstract
The apparent ileal and fecal availabilities of amino acids in four barley samples and in four wheat samples were determined with four growing barrows (Yorkshire × Lacombe), fitted with ileocecal re-entrant cannulae. The experimental rations consisted of 96.8% barley or wheat, 2.7% minerals plus vitamins and 0.5% chromic oxide. True availabilities were calculated based on metabolic ileal and fecal amino acid levels obtained in previous studies. There were differences (P <.05) between the apparent ileal as well as between the true ileal availabilities of lysine, methionine, phenylalanine and glutamic acid in the barley samples. The apparent ileal availabilities ranged from 64.9 to 72.5% for lysine, from 72.1 to 83.9% for methionine and from 64.4 to70.4% for threonine. In the same sequence, the true availabilities of these amino acids ranged from 71.2 to 78.8%, from 75.4 to 87.3% and from 74.6 to 79.3%. There were no differences between the apparent as well as between the true availabilities of amino acids in the barley samples when these were measured by the fecal analysis method. With the exception of serine, there were no differences between the apparent as well as between the true ileal availabilities of amino acids in the wheat samples. The average apparent ileal availabilities were 76.7, 82.1 and 76.5% for lysine, methionine and threonine, respectively. In the same sequence, the average true ileal availabilities of these amino acids were 83.5, 85.0 and 85.7%.
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