PS9-11. Effect of Including Leucaena, Gliricidia, and Guazuma Leaves on Intake, Digestibility, and Methane Emission in Sheep.

Abstract The objective was to evaluate the inclusion of Leucaena leucocephala, Gliricidia sepium, and Guazuma ulmifolia leaves in a low-quality forage-based diet to determine intake, nutrient digestibility, and methane emissions in sheep. The experimental diets were Baseline Diet (BD) = 100% oat hay; T1 = BD + 20% Leucaena leaves (LeL); T2 = BD + 20% Guazuma leaves (GuL); and T3 = BD + 20% Gliricidia leaves (GlL). Eight 61 kg male sheep (Pelibuey x Friesian) were assigned to the diet in a double Latin square design. The animals were housed in metabolic cages with individual automatic feeders and drinkers for four 15-day periods (10 days for diet adaptation and 5 days for feed and fecal sampling). The following parameters were determined: dry matter (DM), nitrogen (N), ash, ether extract (EE), neutral detergent fiber (NDF), acid detergent fiber (ADF), and gross energy. Methane estimates were performed using the IPCC Tier 3 prediction equations. Apparent nutrient digestibility was estimated from total fecal collection, pH, volatile fatty acid production, and ammonia nitrogen (N-NH3) in the rumen contents. Data were analyzed using the SAS MIXED procedure, and treatment means were compared using Tukey's test. A p-value < 0.05 was considered statistically significant, and a p-value < 0.01 was considered highly significant. Table 1 presents the composition and nutritional contribution of the experimental diets. Dry matter (DM) and organic matter (OM) intake increased (P < 0.01) by 15.8% and 14.64%, respectively, with the inclusion of Gliricidia foliage compared to the basal diet. Nutritional intake (NI) and bioavailability (BA) were higher (P < 0.01): 63.7% and 21.54%, respectively, in the shrubby diets compared to the basal diet with oat hay (Table 2). Total N digestibility (TND) was higher (P < 0.01, 53.08%) in animals fed GlL than in the other treatments. Digestible Energy (DE) decreased (P < 0.01, 59.24%) with the addition of tree foliage compared to the basal diet (Table 3). VFA and N-NH3 values increased (P < 0.01) with GlL, by 44.8% and 15%, respectively, compared to LeL, and the addition of tree foliage increased (P < 0.01) CH4 emission rates compared to the basal diet (Table 4). It is concluded that adding Gliricidia leaves to a low-quality forage-based diet improves nutrient intake and digestibility, although it increases methane emissions. For image description, please refer to the figure legend and surrounding text. For image description, please refer to the figure legend and surrounding text. For image description, please refer to the figure legend and surrounding text. For image description, please refer to the figure legend and surrounding text.