Four experiments were conducted to evaluate the nutritional value of palm kernel meal (PKM) from Colombia, Costa Rica, Indonesia, Mexico, and Thailand. Extensive chemical analyses were initially conducted to determine nutritional composition of 10 PKM. The first and second experiments were conducted to determine nitrogen-corrected true metabolizable energy (TMEn) in conventional roosters and standardized amino acid (AA) digestibility in cecectomized roosters for 12 PKM, respectively. The TMEn differed among PKM (P<0.05) and ranged from 1,644 to 2,439 kcal/kg (DM basis) for the 12 PKM. Standardized digestibility of AA varied among samples (P<0.05), e.g., Lys varied from 35 to 60%, Met varied from 65 to 86%, Cys varied from and 29 to 69%, and Thr varied from 53 to 77%. Chemical composition results (%), mean (range), were as follows: CP, 13.7 (11.2-16.6); fat, 7.5 (5.86-10.47); NDF, 64.4 (60.8-67.3); Ca, 0.4 (0.2-0.5); P, 0.7 (0.6-0.8); phytic acid, 1.3 (1.1-1.6). In Experiment 3, phosphorus (P) bioavailability of 2 PKM samples from Mexico (M-PKM) and Costa Rica (CR-PKM) relative to potassium phosphate (KH2PO4) based on tibia bone ash was determined. From 8 to 18 d-of-age, P-deficient corn-soybean meal diets supplemented with 0.05 and 0.1% P from KH2PO4 or 15 and 30% M-PKM and CR-PKM were fed. All diets were fed to 6 replicate pens of 5 chicks. Data were analyzed using a one-way ANOVA and multiple regression analyses. Multiple regression of bone ash (mg/tibia) on supplemental P intake yielded a P bioavailability of 21 and 40% relative to KH2PO4 for M-PKM and CR-PKM, respectively. In Experiment 4, an ad libitum-fed broiler chicken assay was conducted to determine apparent pre-cecal ileal P digestibility for M-PKM and CR-PKM at 2 dietary Ca levels in 2 × 2 factorial treatment arrangement. Diets were fed from 18 to 22 d of age. Semi-purified diets containing 45% M-PKM or CR-PKM as the sole source of P were fed at a Ca:total P ratio of 1.4 and 3.6, respectively. The latter ratio was achieved by adding limestone to increase dietary Ca from 0.3% to 0.75%. Titanium dioxide (TiO2) was used as an indigestible marker and P was kept constant across all diets at 0.21%. Data were analyzed as a 2-way ANOVA with PKM inclusion and Ca:total P ratio as main effects. When Ca level increased from 0.30% to 0.75% for diets containing M-PKM, ileal P digestibility decreased from 37.7% to 23.7%, respectively, while for diets containing CR-PKM, it decreased from 48.1% to 30.0%, respectively.Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2024-03-01 without embargo termsThe student, Jennifer Blair, accepted the attached license on 2023-10-17 at 12:57.The student, Jennifer Blair, submitted this Thesis for approval on 2023-10-17 at 13:03.This Thesis was approved for publication on 2023-10-30 at 15:55.DSpace SAF Submission Ingestion Package generated from Vireo submission #19863 on 2024-03-01 at 13:13:5
