Nutrient composition, volatile fatty acids production, digestible organic matter and anti-nutrtional factors of some agro-industrial by-products of Ethiopia

Abstract

Nutrients, metabolizable energy (ME), anti-nutritional factors, digestible organic matter (DOM) and volatile fatty acids (VFA) production of 17 agro-industrial by-products from Ethiopia were determined. Highest amount of ash was found in fishmeal (FM) and of lignin in sisal waste (SW) and banana peels (BP). Cabbage leftover (CL), onion peels (OnP), papaya peels (PaP) and FM had high CP (137 to 490 g/kg DM) and NPN (51 to 141 g CP/kg DM); distillery by-product (DB) and brewery by-product (BB) had high CP (179 and 187 g/kg DM) and NDF (535 and 396 g/kg DM, respectively) but low NPN (21 and 9 g CP/kg DM). CL, OnP, PaP and FM had low NDF (< 240 g/kg DM). Because of high NDF and lignin, BB and coffee parchment (CPa) had low DOM (507±30 and 322±4 g/kg DM, respectively). CPa and SW had low ME (<6.6±0.3 MJ/kg DM) and DOM (<568±15 g/kg DM); the rest had high ME (7.7 to 13.6 MJ/kg DM) and DOM (>576±9 g/kg DM) except avocado peels (AP) and BB. VFA concentrations were >19.1±1.8 mM except in CPa, FM and AP (<12.1±2.9 mM). Coffee pulp (CPu), CL and MP had high total phenolics (123 to 151 g/kg DM) and tannin (42 to 86 g/kg DM). BP had largest amount of phytate. Hemolytic activity (saponin) was detected in FM, potato peels, SW, CPa and CL. The feeds can serve as sources of energy and protein.