Intake and nutrient digestibility of tropical grasses and legume hay supplemented with tilapia fish silage

Abstract

Two experiments were conducted to determine the effect of supplementation with tilapia fish silage (FS) prepared in laboratory scale silos with addition of cane molasses, on intake and digestibility of tropical grass hay (GH) (Digitaria eriantha, 80%, and Urochloa maximum, 20%), and rhizome perennial peanut hay (RPPH) (Arachis glabrata). In Experiment I, GH was the basal diet and treatments were Control or T1 = GH, and GH supplemented daily with FS at 0.45% (T2) and 0.90% (T3) of the animal body weight (BW). In Experiment II, the basal diet was RPPH and treatments were Control or T1 = RPPH;T2 = RPPH supplemented daily with FS at 0.225% BW; and T3 = RPPH with 0.45% BW. In both experiments nine adult intact rams were used. The animals were fed for eight days of adaptation and six days of data collection in each period. Both experiments used a 3 X 3 Latin Square design. In experiment I dry matter (DM) intake and digestibility of GH increased (P less than 0.05) with FS supplementation, which also increased crude protein (CP) intake. CP digestibility increased (P < 0.05) at each level of supplementation compared to that of the control, but T2 and T3 did not differ significantly. Neutral detergent fiber (NDF) intake was higher (P < 0.05) in T1 than in T3 but similar in T1 and T2. Fiber digestibility was not affected (P greater than 0.05) by the treatments. It was concluded that supplementation of a GH basal diet with FS at 0.90% of BW is the best alternative. In Experiment II, DM digestibility of T3 differed (P less than 0.05) from that in T1 but in T2 did not differ from DM digestibility either in T1 or T3. Intake of DM, CP and fiber were similar in all treatments (P greater than 0.05). Crude protein digestibility was similar at both levels of supplementation and superior (P < 0.05) to that of the control, but fiber digestibility was not affected (P > 0.05). It is concluded that daily supplementation with FS for sheep fed a basal diet of RPPH should be limited to 0.225% of BW. Upon comparing both experiments, voluntary intake of DM, NDF and CP from RPPH was higher than from GH.The legume also showed a higher (P < 0.05) digestibility of DM and CP.