Faecal production in the O. niloticus groups fed the copra meal and palm kernel meal diets were 358.08 ± 7.35 and 372.60 ± 10.19 g DM kg−1 ingested feed respectively, which were significantly higher than the control (274.79 ± 5.44 g DM kg−1 ingested feed) and soybean meal diets (239.49 g DM kg−1 ingested feed) (Fig. 3).