ABSTRACT
A feeding trial, which lasted for seventy days, was conducted in which palm oil mill sludge and biodegraded sweet orange peel mixture was fed to substitute maize in broiler chicken diet at 0%, 5%, 10%, 15%, 20% and 25%. Sweet orange (Citrus sinensis) fruit peel was fermented by soaking for 48 h in retted cassava waste water (CWW) and sundried, to obtain biodegraded sweet orange peel (BSOP). Palm oil mill effluent was filtered with a 0.30 mm pore plastic mesh sieve, poured into a 0.75 ?m pore fine cheesecloth bag and allowed to stand for five hours to produce a paste of palm oil mill sludge (POMS). The POMS was mixed with BSOP in ratio 1:1, sundried, milled to produce a POMS-BSOP mixture. One hundred and eighty day-old Cobb 700 broilers divided into six equal parts, and three replicates of 10 birds each were used. Each part was assigned to one of 6 diets compounded with 0% (T1), 5% (T2), 10% (T3), 15% (T4), 20% (T5) and 25% (T6) of POMS-BSOP mixture. The microbial composition of retted CWW, chemical composition of the POMS-BSOP mixture, and the digestibility of nutrients by the broiler chickens were determined. Isolated from CWW were; Staphylococcus aureus, Streptococcus spp., Salmonella spp., Escherichia coli (bacteria), Aspergillus spp. (fungus) and Candidia spp. (yeast). POMS-BSOP was high in energy (4415.69 kcalME/kg), ether extract (41.50%), crude fibre (25.63%) and dry matter (92.28%), moderate in crude protein (6.83%), low in indigestible lignin (4.90% ADL), alkaloid (0.01%), tannin (0.02%), saponin (0.03%), phytate (0.05%), oxalate (0.15%) and flavonoid (0.17%). Dietary treatments significantly (P<0.05) affected digestibility of ether extract and metabolisable energy and crude protein digestibility by broiler chickens. Dietary maize can be replaced at up to 25% with a POMS-BSOP mixture to improve energy digestibility by broiler chickens.