Improving the feeding value of plantain banana (Musa × paradisiaca L.) leaves by urea treatment or nitrogen supplementation in adult bucks

Banana- and plantain-producing regions generate by-products that could be used as ruminant feed, although plantain leaves fed alone have low nutritive value. This study evaluated feed intake and fecal digestibility of plantain (Musa×paradisiaca L.) leaves in 20 adult bucks over three periods using five diets: fresh leaves (FL), dried leaves (DL), dried leaves supplemented with urea (DLU), dried leaves mixed with hoopvine leaves (DLH), and dried leaves treated with urea during ensiling (DUTL). Diets were offered at approximately 60–70 g DM/kgW0.75 to each animal in individual metabolism cages during 21-day periods, including 7 days of measurements. Data were analyzed using a GLM model including diet and period as main effects. Mean comparisons were performed using Duncan, and significance was declared at P < 0.05. Fresh and dried plantain leaves were rich in ash (14-15% DM) and Neutral Detergent Fiber (NDF) (56-60% DM) but only moderate in crude protein (10-13% DM). Dry Matter Intake (DMI) and NDF digestibility of DL (35.1 g/kgW0.75 and 31.0%, respectively) and FL (40.3 g/kgW0.75 and 39.9%, respectively) were low, reflecting poor feeding value. Urea supplementation of dried leaves (DLU diet) did not improve intake or fiber digestibility (36.6 g/kgW0.75 and 35.3%, respectively), and increased DM intake and NDF digestibility were measured with DLH diet (50.2 g/kgW0.75 and 41.4%, respectively), but the improvements were attributed to the inclusion of hoopvine leaves rather than enhanced utilization of plantain leaves. In contrast, urea treatment during ensiling of dried leaves significantly increased DMI (59.9 g/kgW0.75) and NDF digestibility (51.9%) of DUTL diet. Only this latter diet maintained body weight, whereas goats fed the other diets lost 1.0 to 1.9 kg during each test period. Results indicated that nitrogen supply was not the main limitation of plantain leaves and that urea treatment during ensiling was the most effective strategy to improve their feeding value for goats.