Selección de especies le?osas por vacunos en silvo- pastoreo de un bosque semicaducifolio en venezuela

摘要

The woody plant palatability for cattle in a silvopastoral system on a semi-deciduous tropical forest (SDTF) was evaluated. Epidermal fragments in fecal samples from 14 male cattle Brahman x Holstein (390.4 ± 18.0 kg live weight) grazing during 91 days in 81 ha located in Portuguesa state, Venezuela were evaluated. SDTF was present in 50 ha; the rest of grassland, was mainly composed by Cynodon nlemfuensis, Sporobolus indicus, Cyperus sp. and Axonopus sp. Using the point quarter method on transects, 22 woody plant species were identified they were grouped into 11 botanical families, with 40.9% of species belonging to the Fabaceae family. Guazuma ulmifolia had the greater relative dominancy (60.4%), and together with Pithecellobium lanceolatum and Samanea saman reached the 81.1%. These same species showed the higher importance value index (162.6, 24.8 and 26.5 respectively). Poaceae had the higher relative frequency (49.6%) for epidermal fragments in feces; total woody plants reached 46.2% (Fabaceae: 80.7%). The most selected species were Inga laurina, Machaerium humboldtianum, S. saman and Sida acuta, (Ivlev index= 0.60 ± 0.09). The chemical composition of woody plants foliage suggest a selectivity profile adjusted to the nutrient profile offered by each species. These findings highlight the strategic value of SDTF in silvopastoral systems in tropical environments.