ESTIMATES OF TRUE ILEAL DIGESTIBILITIES OF CORN, SOYBEAN-MEAL AND ALTERNATIVE FEED INGREDIENTS FOR SWINES

Nine crossbred barrows with an initial weight of 52.59+/-.57 kg were e ach surgically fitted with a T-cannula at the terminal ileum in order to measure the coefficients of true amino acid digestibilities (TAAD) of eight feedstuffs for subsequent use in testing the utility of amino acid digestibility values in diet formulation. The feed ingredients i nvestigated were: corn, wheat bran (WB), two sources of soybean meal ( SBM 1 and SBM 2), cottonseed meal (CSM), poultry by-product (PBP), and meat and bone meal (MBM 1 and MBM 2) from two origins. A nitrogen fre e diet (NFD) was used to estimate the endogenous losses of amino acids . The TAAD coefficients in corn and WE were significantly lower (P les s than or equal to.01) than in the other sources except for lysine in CSM and threonine in MBM 1. True lysine digestibility coefficients for corn (59.9%) was in the range of values found in the literature, The SBM 1 and SBM 2 yielded similar (P greater than or equal to.01) amino acid digestibility. The MBM 1 and MBM 2 despite visual differences in appearance were also similar (P greater than or equal to.01). The obta ined estimates are in the range of literature values and can be used t o calculate diets based on the amino acid digestibility.