Amino acid digestibilities in different samples of wheat shorts for growing pigs

An experiment was carried out to investigate-the variability in apparent il eal amino acid (AA) digestibilities in simulated samples of wheat shorts co nsisting of different proportions of wheat bran (WB),wheat shorts (WS), and wheat flour (WF), hereafter referred to as wheat fractions. The proportion s of WS, WE, and WF and the NDF content (DM basis) of the wheat fractions w ere as follows: A, 70% WS, 30% WE, and 42.3% NDF; B, 85% WS, 15% WE, and 41 .8% NDF; C, 100% WS and 41.3% NDF; D, 85% WS, 15% WF, and 35.2% NDF; and E, 70% WS, 30% WF, and: 29.5% NDF. Six barrows, average initial BW of 37.2 kg , fitted with a simple T-cannula at the distal ileum, were fed one of six e xperimental diets according to a 6 x 6 Latin square design. Six diets were formulated to contain 17% CP (as-fed basis). Diets A, B, C, D, and E contai ned 17.53% soybean meal (SBM), which contributed 50% of the CP in these die ts. The wheat fractions contributed the remaining 50% of the CP in these di ets. Diet F contained 35.05% SBM, which was the sole source of dietary CP. Chromic oxide was used as the digestibility marker. During the first experi mental period, the daily dietary allowance was provided at a rate of 5% (wt /wt) of the average BW. Thereafter, the daily dietary allowance was increas ed by 100 g at each successive period. Each experimental period comprised 1 2 d. Following a 7-d adaptation period, feces were collected for 48 h and i leal digesta for a total of 24 h. The: apparent ileal digestibilities of AA in the wheat fractions were calculated using the difference method. The di gestibilities were usually lowest in the wheat fractions containing WE and highest in those containing no WE. The average of the digestibilities of th e indispensable AA was 63.5% for wheat fraction A, which contained 30% WE, and 71.9% for wheat fraction C, which did not contain WB. There were no dif ferences (P > .05) in lysine digestibilities among the wheat fractions, whi ch ranged from 54.7 to 64.1%. Of the indispensable AA, with the exception o f arginine, lysine, and methionine, the apparent ileal digestibility values of AA were negatively correlated (P < .05) with the NDF content in the whe at fractions.