Du Thanh Hang et al., 2010. Livest. Res. Rural Dev., 22 (4): 68

The study was conducted to estimate the oxalate content of the different varieties or species of taro (Alocacia odera, Xanthosoma nigra and Colocacia esculenta) commonly grown by farmers in Central Vietnam; evaluate the different methods of processing the leaves on the content of oxalate; and determine the effects of partial replacement of dietary fish meal by ensiled leaves of taro on the growth performance of pigs (n=16). Results revealed that the oxalate levels in the three species of taro were higher in petioles (range of 1326 to 3567 mg/100 g DM) than in leaves (770 to 2531 mg/100 g DM), and within each plant part, values were highest for Alocacia odera and lowest for Xanthosoma nigra, with intermediate values for Colocacia esculenta. Sun-drying, soaking, cooking and ensiling all reduced the concentration of oxalate, but the effects were most pronounced (50% reduction) for cooking and ensiling. DM and crude protein intakes of pigs fed with basal diet of maize, rice bran, cassava root meal and fish meal did not differ when ensiled taro leaves (ETL) replaced fish meal by up to 30% silage in the diet DM. However, fibre intake increased linearly with replacement rate of ETL. Growth rate was reduced only slightly up to the 30% inclusion rate of ETL, at which point the growth rate significantly decreased. The trends for feed conversion were similar to the liveweight gain. It is suggested that ETL can replace up to 30% of the dietary fish meal (20% ETL in the diet DM) in diets of growing pigs without performance loss.