Utilisation of giant taro (Alocasia macrorrhiza) root meal with or without coconut oil slurry by layers and broilers

Abstract

Replacements of maize with Alocasia macrorrhiza root meal (AMRM) with or without added coconut oil slurry (COS) in poultry diets were investigated in a series of two experiments. In Experiment 1, the replacement of maize with two levels (10% and 20%) each of AMRM and AMRM–COS on egg production and egg quality was investigated. Experiment 2 investigated the same treatments as in Experiment 1 on broiler performance. In both experiments, each diet was fed to four replicates of 10 birds in a completely randomised design. There was no marked effect on feed intake (FI) in both experiments (P > 0.05). In Experiment 1, percentage hen-day production and feed conversion ratio were depressed (P < 0.05) on 20% AMRM and egg weight on 10% AMRM, but these depressing effects were overcome by COS addition. Egg mass was significantly (P < 0.05) increased on 20% AMRM–COS compared with the other AMRM groups, but did not differ (P > 0.05) between the control and AMRM–COS. Haugh unit and percentage shell were not affected by the treatment (P > 0.05). In Experiment 2, bodyweight gain was significantly (P < 0.05) reduced with the inclusion of AMRM in the diet, with the lowest gain on 20% AMRM–COS. Feed conversion ratio was adversely affected when AMRM was included at a concentration greater than 10% of dietary maize (P < 0.05). Coconut oil-slurry treatment of the meal did not improve performance. It was concluded that inclusion of AMRM at a concentration greater than 10% dietary maize adversely affects the performance of both layers and broilers. Treatment of AMRM with COS at 9 : 1 overcomes these adverse effects in laying hens, but not in broilers. More research is warranted on the effects of higher concentrations of COS-treated AMRM in the diet on layers, and on processing methods that will improve performance of poultry.