Forages and Pastures

摘要

The seasonal production of forage is one of the main factors limiting animalperformance in pasture-based systems under tropical climate conditions.It requires the search for alternative feedstuffs to offer animalsduring periods of forage scarcity to maximize animal performance. Theobjective of this study was to evaluate parameters of bromatologicalquality of silage of 3 genotypes of sorghum biomass (B012, B017, andB018) with 4 levels of sugarcane inclusion (0, 20, 40, and 60%). Theexperiment was conducted using a completely randomized design in afactorial scheme with 4 repetitions. The material was ensiled using PVCsilos (10 cm diameter by 45 cm long) that were kept closed for 60 d.Upon opening, dry matter (DM), ash content (AC), organic matter (OM),and pH were measured. The data were analyzed using a 2-way ANOVAfollowed by the Tukey test (α < 0.05). The silage of the genotype B012had a higher (P < 0.05) DM (mean ± standard deviation = 29.3 ± 1.90)compared with the other genotypes (B017 = 27.3 ± 1.54 and B018 = 26.4± 1.32). We observed a linear negative effect (P < 0.05) of sugarcane onDM content, in which a reduction of 0.30% of DM was observed foreach 10% increase in sugarcane inclusion. We observed an interactioneffect (P < 0.05) between genotypes and sugarcane levels for OM andAC. There was no effect of sugarcane levels on OM and AC of the B012genotype silage (P > 0.05). A quadratic positive effect of sugarcane levelswas observed on OM of the silages of the genotypes B017 and B018 (P< 0.05), in which the lowest values were observed at 7.63% and 1.29%inclusion of sugarcane respectively. A quadratic negative effect was observedon AC of the same genotypes (P < 0.05), in which the highestvalues were observed at the same sugarcane level inclusion as for OM.The silage of the genotype B012 had a higher (P < 0.05) pH (4.26 ± 0.07)than the other genotypes (B017 = 4.14 ± 0.04 and B018 = 4.17 ± 0.06).The genotypes of biomass sorghum evaluated in our study respondedsatisfactorily to the fermentation process, which could result in silagesof good quality, but the inclusion of sugarcane is not recommended.