Bioavailable Pantothenic Acid in Cereal Grains and Soybean Meal

Abstract

Summary Three experiments were conducted to determine the bioavailability of pantothenic acid (PA) in corn, barley, sorghum, wheat and dehulled soybean meal (SBM). Crossbred chicks were fed a purified diet essentially devoid of PA from day 1 to 7 posthatching. Crystalline amino acid diets were fed ad libitum during the test period (8 to 21 or 8 to 22 days posthatching). The test ingredients (15% of the diet) were incorporated into the PA-free basal diet at the expense of cornstarch. A PA standard curve was generated by supplementation of the basal diet with 0, 1, 2 or 3 ~g PA/g diet. The slope-ratio assay was used to determine bioavailability estimates (micrograms PA/gram test grain = grams gain/gram test grain consumed + grams gain/microgram PA consumed). Corn, barley, sorghum, wheat and SBM were found to contain 4.6 + 1.3, 11.1 -+ 1.2, 6.0 + 1.5, 9.6 + 1.3 and 21.7 -+ 1.3 #g bioavailable PA/g, respectively. The value of 21,7/~g PA/g for SBM is higher than previously reported estimates. Graded levels of SBM (0, 5, 10 and 15%) were fed so that a more accurate estimate of the PA content of SBM could be obtained. This assay yielded an estimate of 17.7 /ag PA/g SBM, which is also well above previously reported values. It is possible, therefore, that these values represent overestimates because SBM may stimulate growth, apart from its contribution of PA, when added to crystalline amino acid chick diets. A fourth assay was conducted tO determine whether PA supplementation is necessary in a corn-SBM-based diet. A small response was observed in rate and efficiency