Detoxification of cassava (Manihot esculenta Crantz) foliage and its utilization as water buffalo (Bubalis bubalis L.) feed

Analysis showed that fresh cassava foliage contains hydrocyanic acid (HCN) ranging from 86-186 ppm (fresh basis). Processing by wilting or drying reduced (P0.01) HCN content below 80 ppm (dry basis) for low and medium HCN varieties but not for high HCN variety which was reduced only by ensiling. Silage pH (3.5-4.5) and physical appearances indicated that cassava foliage [CSF] is a good silage material. Feeding value evaluation revealed its potential as ruminant feed. In situ digestibility evaluation showed that total dry matter and protein disappearance were lower (P0.01) in dried compared to ensiled CSF. On the contrary, in vivo digestibility of protein was higher in dried compared to ensiled CSF. Buffaloes fed with different levels of cassava foliage showed that average daily gain (ADG) increased (P0.01) from 0.74 in control (0 percent CSF) to 0.86 with 50 percent CSF in roughage. Feeding CSF at 75 percent of roughage did not improve animal performance. Dry matter intake was highest at 25 percent CSF feeding with 2.36 percent of body weight. This reduced to 2.28 percent at 50 percent CSF and 2.14 percent at 75 percent CSF. Feed intake reduction at high CSF silage feeding could be attributed to increased HCN ingestion. Sulfur supplementation (2 grams/kg/CSF) as aid in thiocyanate formation during HCN detoxification process increased (P0.05) dry matter intake for animals fed 75 percent CSF but not for those fed 50 percent CSF. However, sulfur did not increase liveweight gain with ADG of 0.9-0.94 kg at 50 percent CSF feeding and 1.01-1.02 kg at 75 percent CSF feeding. Income analysis in CSF-based feeding showed that at 0 percent CSF, net income over feed cost was P18.22/kg weight gain. This increased to P20.41/kg for 25 percent CSF, P20.99 kg for 50 percent CSF and P22.19/kg weight gain for 75 percent CSF. Comparative income analysis of different cassava-based production system showed that income increased from P15,360 in cassava without defoliation to P22,160 in cassava with defoliation five months after planting and P36,775 for cassava with livestock integration