Effect of treatment of cocoa-pods with Aspergillus niger on liveweight gain and cocoa-pod intake of Bali (Bos sondaicus) cattle in South-East Sulawesi

Abstract

Cocoa-pods, a by-product of the cocoa industry, could potentially be used as a feed resource for ruminants in eastern Indonesia. However, little is known regarding the optimal amount to be included in the diet or the effect of treatment with Aspergillus niger on cocoa-pod quality. In this experiment the effect of rate of inclusion (0 or 10 g DM/kg liveweight.day or ad libitum) of A. niger-treated or untreated cocoa-pods in the diet on intake and liveweight gain of Bali cattle (Bos sondaicus) was investigated. Ad libitum intake of cocoa-pods was greater when they were treated with A. niger (17.1 ± 0.07 g DM/kg liveweight.day; mean ± s.e.m.) compared with untreated cocoa-pods (13.9 ± 0.19 g DM/kg liveweight.day) when offered as the sole component of the diet. The digestibility of A. niger-treated cocoa-pods (448.9 ± 23.7 g/kg) was not different to untreated cocoa-pods (422.9 ± 13.9 g/kg) when fed ad libitum, which was lower than native grass (527.2 ± 10.7 g/kg). Animals offered A. niger-treated cocoa-pods lost less liveweight than animals offered untreated cocoa-pods when offered ad libitum (–0.104 ± 0.02 and –0.280 ± 0.02 kg/day, respectively), and grew faster when included in the diet at 10 g DM/kg liveweight.day (0.233 ± 0.02 and 0.129 ± 0.02 kg/day, respectively). In conclusion, in areas where cocoa plantations exist, cocoa-pods may be a useful feed resource for ruminants when fed at low levels of inclusion in the diet. The treatment of cocoa-pods with A. niger will result in increased liveweight gain. However, it is unlikely such treatments will be adopted by small-holder farmers due to the increased requirements for inputs, such as time, labour, funds, equipment, and technical skills.