THE EFFECT OF DIETARY-FAT CONTENT ON AMINO-ACID DIGESTIBILITY IN YOUNG-PIGS

Studies were carried out with 12 pigs (Yorkshire x Landrace) to determ ine the effect of dietary fat content on amino acid digestibility. The pigs were weaned at 21 d of age and fitted with a simple T-cannula at the distal ileum at 27 or 28 d of age. After a 7-d recuperation perio d, the pigs were fed one of four isonitrogenous cornstarch-based soybe an meal diets (22.5% CP) containing 3.2, 6.2, 9.2, or 12.2% canola oil according to a balanced two-period change-over design. The pigs were fed four times daily, equal amounts, at 6-h intervals. The diets were supplied at a rate of 5% of the average body weight that was determine d at the initiation of the first (11.0 kg) and second (12.5 kg) experi mental period. Each experimental period consisted of 10 d. Feces were collected for 48 h on d 6 and 7 and ileal digesta for 24 h during d 8, 9, and 10. Chromic oxide was used as digestibility marker. The appare nt ileal digestibilities of most of the amino acids increased linearly (P < .05) with increasing dietary fat levels. There were differences (P < .05) in the ileal digestibilities of most of the amino acids betw een the diets containing 3.2 and 12.2% canola oil. Conversely, the die tary level of inclusion of canola oil did not affect (P > .05) the fec al amino acid digestibilities. The protein-sparing effect of additiona l canola oil inclusion results, in part, from an increase in ileal ami no acid digestibility.