Amino acid digestibility and concentration of digestible and metabolizable energy in copra meal, palm kernel expellers, and palm kernel meal fed to growing pigs

Abstract

Two experiments were conducted to determine apparent ileal digestibility (AID) and standardized (SID) ileal digestibility of AA (Exp. 1) and the concentration of DE and ME (Exp. 2) in copra meal (CM), palm kernel expellers from Indonesia (PKE-IN), palm kernel expellers from Costa Rica (PKE-CR), palm kernel meal from Costa Rica (PKM), and soybean meal (SBM). In Exp. 1, 6 barrows (BW = 34.0 ± 1.4 kg) were randomly allotted to a 6 × 6 Latin square design with 6 diets and 6 periods. One diet contained 30% SBM and 4 diets were formulated with 20% SBM and 30% (as-fed basis) CM, PKE-IN, PKE-CR, or PKM. The last diet was an N-free diet that was used to measure basal endogenous losses of CP and AA. The SID of CP and all indispensable AA except Met, Thr, and Trp was less (P < 0.05) in CM than in SBM, and the SID of CP and all indispensable AA except Trp was less (P < 0.05) in PKE-IN than in SBM. There were no differences (P > 0.05) in the SID of CP and all indispensable AA between PKE-CR and SBM, but the SID of CP and all indispensable AA were less (P < 0.05) in PKM than in SBM. The SID of CP was less (P < 0.05) in PKM compared with CM and PKE-CR, but there were no differences (P > 0.05) in the SID of all indispensable AA among CM, PKE-IN, PKE-CR, and PKM. In Exp. 2, 48 barrows (BW = 35.2 ± 3.0 kg) were housed individually in metabolism cages and allotted to 6 diets in a randomized complete block design with 8 replicate pigs per diet. A corn-based diet and 5 diets containing 70% of the corn diet and 30% of CM, PKE-IN, PKE-CR, PKM, or SBM were formulated, and the DE and ME in CM, PKE-IN, PKE-CR, PKM, and SBM were calculated using the substitution procedure. The DE (3692, 3304, 2994, and 2905 kcal/kg DM) and ME (3496, 3184, 2883, and 2766 kcal/kg DM) in CM, PKE-IN, PKE-CR, and PKM, respectively, were less (P < 0.05) than the DE and ME in SBM (4275 and 4062 kcal/kg DM, respectively). Copra meal had greater (P < 0.05) DE than PKE-IN, PKE-CR, and PKM and greater (P < 0.05) ME than PKE-CR and PKM. The DE in PKE-IN was greater (P < 0.05) than in PKM. In conclusion, the SID of most indispensable AA is less in CM, PKE-IN, and PKM than in SBM, but no differences among CM, PKE-IN, PKE-CR, and PKM were observed. The concentrations of DE and ME are less in CM, PKE-IN, PKE-CR, and PKM than in SBM. The DE and ME of CM are greater than in PKE-CR and PKM.