Nutritional Potential of Some Invasive Species of Macaronesia for Ruminants

Abstract

Macaronesia islands' invasive plant use in animal feed or composting may bring economic and environmental benefits to the region. Arundo donax, Pennisetum setaceum, Agave americana, and Ricinus communis, present in the three archipelagos (Canary, Azores and Madeira), were characterized chemically and biologically. A. donax and P. setaceum showed elevated crude protein (CP) content, 13.25 and 16.33 DM%, respectively, and extremely high NDF values, 75.87 and 80.83 DM%, with a DM digestibility of 55.02 to 59.77%. A. americana showed a low NDF value (22.78 to 27.94 DM%) and a very low CP value (4.24 to 5.61 DM%). However, its DM digestibility was high (79.89 to 86.33%). R. communis presented the best values for CP (24.62%) and NDF (26.56 DM%), however, due to the presence of toxic substances (ricin), it cannot be easily used in animal feed. The P. setaceum and R. communis were found to be the least gas-producing forage, with A. americana being the major producer. To increase these plants' value for animal feed, treatment with urea or NaOH to A. donax and P. setaceum, and enrichment with nitrogen to Agave is proposed. Due to its toxic properties, R. communis must be used in composting.