THE EFFECT OF FOOD DRY-MATTER INTAKE ON ENDOGENOUS ILEAL AMINO-ACID EXCRETION DETERMINED UNDER PEPTIDE ALIMENTATION IN THE 50 KG LIVEWEIGHTPIG

The daily ileal excretion of amino acids was measured at different foo d dry matter intakes for the 50 kg liveweight pig under conditions of peptide alimentation. The experiment comprised two cross-over design t rials each involving four pairs of entire male pigs fitted with simple T-cannulae at the terminal ileum and fed a hydrolysed casein semi-syn thetic diet. Each pair of pigs received one of four sequences of food dry matter intake arranged in a Latin square design, namely 0-06, 0.08 , 0.10 and 0.12 (Trial 1) and 0.05, 0.07, 0.09 and 0.11 (Trial 2) of m etabolic bodyweight (W0.75) day-1. Each pig received the diet at its d escribed level of intake for 8 days, with continuous 24 h collection o f ileal digesta on the fifth and eighth days. Chromic oxide was includ ed in the diet to permit correction of ileal flows to complete digesta collection. Pooled digesta from each pig at each level of dry matter intake were centrifuged and ultrafiltered and the high-molecular-weigh t fraction was analysed for amino acid and nitrogen contents. There we re significant (P < 0.05) linear relationships between endogenous ilea l amino acid, nitrogen and dry matter excretion (mg day-1) and food dr y matter intake (g day-1) except for lysine, glutamic acid and phenyla lanine which increased in a curvilinear manner (P < 0.05). The results indicate that dietary dry matter intake influences endogenous excreti on from the ileum. The relationships, determined under physiological c onditions, provide preliminary data on the magnitude of small intestin al amino acid loss in the young growing pig.