The effects of feed intake and purified cellulose on the endogenous ileal amino acid flow in growing pigs

Abstract

The effects of level of feed intake (0.8, 1.2 and 1.6 kg/d) and body-weight of the pig (49 and 92 kg) in Expt 1, and dietary neutral-detergent fibre (NDF; 30, 60, 90, 120 and 150 g/kg) in Expt 2 on the endogenous ileal flow of amino acids (AA) and nitrogen were studied with protein-free diets into which purified wood cellulose was incorporated at the expense of maize starch. In Expt 1, one of the protein-free diets containing 90 g NDF/kg was used. Female pigs were fitted with a simple ‘T’ cannula at the terminal ileum. In Expt 1, the endogenous ileal AA and N flow, expressed as g/kg dry matter (DM) intake, decreased significantly (P< 0.05) with increasing DM intake, except for proline. By contrast, the values expressed as g/d remained constant. There was no significant difference in endogenous ileal flow (P> 0.05) between initial body-weights of 45 and 90 kg except for histidide, isoleucine, phenylalanine, threonine, valine and serine, in which the ileal flow determined at the higher body-weight was significantly higher (P< 0.05). In Expt 2, the effects of dietary cellulose levels on the endogenous ileal flow of AA and N were not significant (P> 0.05), although the values tended to increase as dietary cellulose levels increased for most AA and for N. It is concluded that the daily endogenous ileal flow of AA and N remains relatively similar at different DM intake and cellulose levels. Therefore, correction of apparent ileal digestibility of AA and N to the true ileal digestibility should be made with the endogenous ileal flow values expressed on a daily amount basis, not the values expressed on a DM intake basis