Nitrogen-corrected apparent metabolizable energy and apparent ileal digestibility of amino acids of thermally processed food waste for broilers

Abstract

SUMMARY: To determine the economic viability of utilizing food waste in animal feed, knowledge of the nutrient availability and variability is needed. The objective of this study was to determine the nutrient variability, nitrogen-corrected apparent metabolizable energy (AMEn), and apparent ileal digestibility (AID) of food waste (FW) when fed to broilers. Dining hall FW products were created by dividing 30-day collections into weekly intervals resulting in product 1 (FW1; d 1–7), 2 (FW2; d 8–14), 3 (FW3; d 15–22), and 4 (FW4; d 23–30). Each product was mixed with soybean meal (SBM) and extruded to a target barrel temperature of 140°C. At hatch, 420 and 360 one-day-old male broilers (Ross 308, Sallisaw, OK) were used in an 18-day study to determine AMEn and AID amino acid (AA), respectively. Treatments were randomly assigned to cages, resulting in 10 cages per treatment with 6 broilers per cage. Treatments for both studies consisted of conventional SBM, extruded SBM (ESBM), FW1, FW2, FW3, and FW4. Data were analyzed using PROC GLIMMIX in SAS v. 9.4 (Cary, NC). Broilers fed ESBM had increased (P < 0.01) AID of indispensable AA, except Met, when compared to SBM. Of the FW products, broilers fed FW1 and FW3 had increased (P < 0.01) AID of indispensable AA, except Leu, when compared to FW2 with FW4 AID AA being intermediate. The FW3 had increased (P < 0.01) AMEn when compared to SBM, ESBM, FW1, and FW2, with FW4 being intermediate to all other treatments. In conclusion, extruding FW blended with SBM successfully served as a nutrient source for broilers.

Keywords

• amino acid digestibility
• food waste
• soybean meal
• apparent metabolizable energy
• extrusion