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-Forty-three batches of cereals (10 of wheat, 10 of triticale, 5 of barley, 5 of rye, 7 of maize and 6 of sorghum) were analysed and studied for their nitrogen (N) and amino acid (AA) ileal digestibility. Each batch was tested on four castrated male pigs, weighing between 30 and 90 kg, and fitted with an end-to-end ileo-rectal anastomosis. Ileal true digestibility (TD) of AA was calculated by correcting ileal apparent digestibility (AD) for basal endogenous AA losses, measured by means of a protein-free diet. Ileal real digestibility (RD) of AA was calculated by correcting AD for total endogenous AA losses, estimated by a multiple regression model. TD of N and most AA decreased (P < 0.001) from wheat, triticale and maize, to barley and sorghum and to rye (90.3, 88.7, 89.9, 85.4, 83.7 and 80.1%, respectively, for the sum of all AA). Estimates of endogenous N losses decreased (P < 0.001) from triticale, sorghum and wheat, to maize, barley and rye (on average 3.10, 2.93, 2.63, 2.43, 2.27 and 2.16 g N . kg -1 DM ingested, respectively). Barley excluded, there was a trend toward increasing endogenous AA losses with increasing dietary acid detergent fibre (ADF) concentration (r = 0.57, P < 0.001). Barley caused low endogenous N losses relative to its ADF concentration.

. 2000. Ileal digestibility of protein and amino acids of feed peas with different trypsin inhibitor activity in pigs. Can. J. Anim. Sci. 80: 643-652. Ileal digestibility of protein and amino acids was measured in pigs fed 13 round, tannin-free peas samples and related to the following physical, chemical and biological characteristics of these samples: thousand-seed weight, proportion of hulls, starch, fibre, crude protein, ether extract and ash contents, trypsin inhibitor activity and trypsin inhibitor activity per unit of crude protein (TIAP). Each pea sample was included in a diet containing starch, sucrose, minerals and vitamins and fed to four barrows (50 to 100 kg) fitted with an endto-end ileo-rectal anastomosis. Standardised ileal protein and amino acid digestibilities, except for alanine of peas decreased linearly with increasing TIAP (P < 0.01) and was not affected by fiber content. For example standardized ileal digestibilities values (%) decreased by -0.1975, -0.1617, -0.2171, -0.2630, -0.2029 and -0.3536 per unit of TIAP (expressed in unit of trypsin inhibited per milligram crude protein), respectively, for crude protein and lysine, threonine, methionine, cystine and tryptophan.

Phytasic activity and phytic P content, which are important factors in determining the availability of P, were measured in 56 wheat samples. The different agronomic and genetic factors which could have an influence on these two variables were studied, specifically N and/or P fertilisation, date of harvest, preharvest sprouting and variety of French wheat. Phytasic activity ranged from 206 to 775mUg−1, with an average of 508mUg−1 and a standard deviation of 109mUg−1. Only the variety of wheat appeared as a significant factor explaining the endogenous phytasic activity (P=0·006). The phytic P content varied between 0·92 and 2·80gkg−1 DM, with an average of 2·18gkg−1 and a standard deviation of 0·35gkg−1 DM. None of the factors studied significantly affected the phytic P content of the wheat. This content was correlated with the total P content (r=0·56;P<0·05). The activity of the endogenous phytase was independent of the quantity of its substrate, the phytic phosphorus of the kernels of wheat.