THE EFFECT OF DIETARY CRUDE PROTEIN LEVEL ON ILEAL AND FECAL AMINO-ACID DIGESTIBILITY IN EARLY-WEANED PIGS

Studies were carried out with 12 pigs (Yorkshire x Landrace), weaned a t three weeks of age, to determine the effect of the dietary level of crude protein on the ileal and fecal digestibilities of protein and am ino acids. The pigs, fitted with a simple T-cannula at the distal ileu m, were fed four com starch-based diets formulated to contain 16.5, 19 .5, 22.5 and 25.5 % crude protein from soybean meal according to a bal anced two-period change-over design. The pigs were fed four times dail y, equal amounts at 02.00, 08.00, 14.00 and 20.00 h, at a rate of 5 % (w/w) of the four experimental diets (Table 1) according to a balanced two period changeover design (GILL and MAGEE 1976). Each experimental period comprise 9 d (5 d adaptation followed by a 4-d collection). Th e pigs were fed the experimental diets at a rate of 5 % of the average body weight which was determined 8 h prior to the initiation of each experimental period. The average body weights of the pigs at the begin ning of the first and second experimental period were 7.9 +/- 1.1 and 9.6 +/- 1.2 kg, respectively. The total daily allowance was offered in 4 meals of equal amounts at 02.00, 08.00, 14.00 and 20.00 h, respecti vely. All the pigs usually consumed their meal allowance within 2 h.