ILEAL AMINO ACID DIGESTIBILITY IN LOW PROTEIN, AMINO ACID SUPPLEMENTED DIETS IN GROWING PIGS

Abstract

An ileal digestibility trial with growing pigs (Hampshire-Yorkshire) was carried out to evaluate the effect of amino acid supplementation on a low protein diet (grain sorghum-soybean meal), on protein and amino acid digestibility. The grain sorghum (yellow endosperm) had 8.9 % crude protein (CP), 0.21 % Lys, 0.33 % Thr, 0.38 % Met+Cys, 0.35 % Ile, 0.11 % Trp, 0.46 % Val and 0.22 % His. Five pigs (initial body weight, BW 25 kg) were fitted with a cannulae at aproximately 10 cm from the ileo-caecal junction. After recovery (approximately 15 days) pigs were randomly assigned to three diets (fed at 0730, 1030, 1630 and 2130 h), during three 10-d feeding periods: 7 d of adaptation, 3 d for sampling. Intestinal content was collected after the second meal, from day 8 to 10, into bags containing trichloroacetic acid (TCA). Dietary treatments were the following: T1, basal diet (91 % grain sorghum, 5 % soybean meal, vitamins and minerals) with 10.5 % CP; T2, the same as T1 plus 0.45 % Lys + 0.15 % Thr + 0.08 % Ile + 0.08 % Met; T3, control diet with 16.5 % CP, grain sorghum-soybean meal. Each treatment was replicated five times. Dietary protein level affected Arg, His, Ile, Lys, Met, Thr (p