Comparison of animal productivity and profitability between a silvopastoral system (Brachiaria brizantha associated with leucaena leucocephala) and a conventional system (B. brizantha+Chicken manure)

The impacts of a Silvopastoral System (SPS) upon animal productivity (daily and total weight gain), biomass availability and production system profitability were evaluated in two contrasting production systems, one with Brachiaria brizantha pasture and chicken manure feed and the other with Brachiaria brizantha in association with Leucaena leucocephala. The study was carried out in San Juan Chiquito de Esparza, in the county of Puntarenas, Costa Rica with an average temperature of 27°C and with an annual precipitation that varied between the 1500 and 2000 mm. The study was carried out in the dry as well as the rainy season, to be able to include data from both periods. To evaluate animal productivity, 12 weaned calves of mixed breed Brown-Brahmin with homogeneous phenotypic characteristics and an average weight of 193.83±20.71 kg were randomly distributed in an experimental design with two treatments and six repetitions. Biomass availability and grass and leucaena quality were measured in two treatments and during the wet and dry season. Economic analysis was performed with a partial budget and a 12 years model of both systems. The ANOVA results did not show significant differences with respect to daily or total weight gain between treatments in either wet or dry seasons but calves experienced significantly more weight gain in the rainy season than in the dry season, regardless of treatment. With regard to the Leucaena quality variables, significant differences were found between seasons for dry mass and tannins not for raw protein, DMD in vitro and mimosine. For the Brachiaria pasture, significant differences were found respect to availability dry mass, raw protein and DMD in vitro between treatments and between seasons. Economic results indicated that the silvopastoral system was more profitable than the conventional system in the 12 years model used. These overall results represent an importan