Assessment of browsed plants in a sub-tropical forest frontier by means of fuzzy inference.

Browsing of forest frontiers by cattle in sub-tropical landscapes is detrimental to ecosystem health, but essential to smallholder livelihoods. We described a silvopastoral landscape, searching for browsed plants to assess how much of the forest is actually used for this end, and also searching for potential new useful species for silvopastoral purposes. The first objective was accomplished through a floristic description, making observations of individuals with browsing marks. Information from interviews, bromatological analyses and vegetative propagation tests further complemented this information to achieve the second objective. We classified the results using Fuzzy Inference Systems (FISs). A great variety of nutritious browsed plants was found, distributed across various types of vegetation, growth habits and taxonomic groups: forest frontiers already are like silvopastoral systems. Various plants like Acalypha leptopoda, Montanoa tomentosa and Verbesina perymenioides are interesting prospects for further intensification of silvopastoral systems.

Evaluation of local energy sources in milk production in a tropical silvopastoral system with Erythrina poeppigiana.

An experiment was carried out to determine the effect of four local energy sources (sorghum grain, green banana, polished rice, and sugarcane molasses) fed to dairy cows on intake, milk production and composition, and economic viability in a silvopastoral system in Costa Rica (Turrialba). Twelve grazing cows (Jersey × Central American Milking Creole), with a mean live weight of 332 kg (SD 34), were supplemented with 0.5 kg of dry matter (DM)/100 kg/LW of Erythrina porppigiana fresh foliage daily. Experimental design was a replicated change-over 4 × 4 Latin Square. The pasture composition was 11 and 17 % of star grass (Cynodon niemfuensis), 32 and 28 % of ruzzi grass (Brachiaria rusisiensis), and 45 and 42 % of natural grasses (Axonopus compresus and Paspalum conjugatum) at initial and final times of the essay, respectively. The grass allowance was 30.14 DM/cow/day. Significant differences were found among treatments for variable milk fat content (P < 0.05). Sorghum presented the highest (41.2 g/kg milk) content of milk fat, followed by green banana (39.2 g/kg milk), polished rice (38.3 g/kg milk) and molasses (38.1 g/kg milk). Non-significant differences (P > 0.05) resulted for total milk production (sorghum 9.0 kg/cow/day; green banana 8.9 kg/cow/day; polished rice 8.8 kg/cow/day; molasses 8.6 kg/cow/day) and fat-corrected milk (FCM). The financial analysis showed that all treatments were economically viable; however, supplementation with green bananas and molasses were the most favorable due to the low costs incurred.