Amino acid digestibility in copra expellers and palm kernel expellers by growing pigs

An experiment was conducted to determine the coefficient of ileal apparent digestibility (CIAD) and the coefficient of ileal standardized digestibility (CISD) of crude protein (CP) and amino acids (AA) in copra expellers (CE) and palm kernel expellers (PKE) by pigs. Six boars fitted with a T-cannula in the distal ileum with an initial body weight of 65.2 ± 5.4 kg were individually housed in pens equipped with a feeder and a nipple drinker. A replicated 3 × 3 Latin square design was employed with 3 dietary treatments, 3 periods, and 6 animals. Two experimental diets were prepared to contain 400 g/kg of CE or PKE as the sole source of nitrogen. A nitrogen-free diet was also prepared to estimate the basal ileal endogenous loss of CP and AA. All diets contained 5 g/kg chromic oxide as an indigestible index. The CIAD of CP in CE was greater (P=0.002) than in PKE (0.294 vs. 0.051). The values for the CIAD of all indispensable AA except histidine and lysine in CE were also greater (P<0.05) than in PKE. The CISD of CP in CE was greater (P=0.014) than in PKE (0.676 vs. 0.528). The values for the CISD of all indispensable AA except histidine, isoleucine, and lysine in CE were greater (P<0.05) than in PKE. In conclusion, the digestibility of CP and most AA in CE was greater than in PKE.