Concentrations of Digestible, Metabolizable, and Net Energy in Coconut Co-products Fed to Growing Pigs

Abstract

This experiment was conducted to determine the concentration of digestible (DE), metabolizable (ME), and net energy (NE), and to develop prediction equations for DE and ME in coconut co-products (CCP) fed to growing pigs. The CCP used were copra meal (CM), protein enriched copra meal (PECM), and white copra (WC) obtained from the different sources in the Philippines. Twenty-two growing barrows (PIC L337 × C24; initial BW 18.74 ± 0.91 kg) were individually housed in metabolism cages that allowed for a total but separated collection of feces and urine. Pigs were arranged in a replicated 11 × 3 Youden square design with 11 dietary treatments at three periods each. A basal diet that contained 96.26% corn, and ten additional diets consisting of 70% basal diet and 30% CCP were formulated. All diets have the same proportion of corn and other ingredients. Fecal, urine, diet, and CCP samples were analyzed for gross energy (GE) using bomb calorimetry. The DE and ME concentrations of CCP diets and ingredients were calculated. The NE of diets and ingredients were estimated using the prediction equation (NE = 0.870 × ME – 442). The DE, ME, and NE concentrations differed (P < 0.001) among CCP and ranged from 1,843 to 3,284, 1,666 to 3,211, and 1,008 to 2,352 kcal/kg DM, respectively. The DE (3,193 kcal/kg DM), ME (3,074 kcal/kg DM), and NE (1,774 kcal/kg DM) concentrations of CM was greater (P < 0.001) than PECM (1,859, 1,717, and 1,052 kcal/kg DM, respectively) but with similar DE (2,657 kcal/kg DM), ME (2,562 kcal/kg DM), and NE (1,787 kcal/kg DM) of WC. However, the DE, ME, and NE of WC was greater (P < 0.001) than PECM. A positive correlation (r ≥ 0.72; P < 0.05) was observed between the DE and ME and acid detergent fiber (ADF) in 8 CCP (excluding WC samples). The DE and ME concentrations in CCP may be predicted using the following equations: 1) DE = -715.30 + 101.42 × % ADF (R2 = 0.52, RMSE = 403.85, P = 0.04); and 2) ME = -983.16 + 106.13 × % ADF (R2 = 0.51, RMSE = 427.42, P = 0.04). In conclusion, DE and ME concentrations differ among CCP sources fed to growing pigs. Moreover, DE and ME values in CCP can be predicted using ADF as independent variable.