INFLUÊNCIA DA ESTRUTURA DA VEGETAÇÃO NA SELEÇÃO DA DIETA POR OVINOS EM ÁREA DE CERRADO

Abstract

It was objective to evaluate the influence of vegetation structure in the selection of plant species by sheep in Cerrado (Brazilian savanna). The research was conducted in an area of Cerrado sensu stricto in the north of Minas Gerais between January 2009 and March 2010. A phytosociological survey conducted the anal-ysis of the vegetation structure, using the plot method. In the tree stratum were delimited 38 continuous plots of 20 m × 20 m. In the regenerant stratum, were allocated sub-plots of 5 m × 5 m. In herbaceous stratum were made two transects in the area of pasture and every 2 m, with the movable square of 0.50 cm × 0.50 cm, 283 points for each transect (566 m).To the identification of the selected species, were used three sheep of the breed Santa Inês, which were kept by grazing in the experimental area and accompanied by observers. In the vegetation were identified 1288 tree, 102 regenerating and 1388 herbaceous individuals, grouped in 117 species distributed in 72 genera and 33 families, among these species: Tachigali rugosa, Heteropterys by sonimifolia, Astronium fraxinifolium, Lantana fucata, Evolvulus sp. e Rhynchospora sp. were important. The selected spe-cies by sheep in grazing, both in the rainy and dry season, in more than 50% species were: Casearia sylvestris, Erythroxylum deciduum, Heteropterys by sonimifolia e Ximenia americana. The feeding preference of sheep in the rainy season was by the species of herbaceous stratum, in the dry period by the species of the tree and re-generating strata. These species are structural bio-indicators of the Cerrado biome, for the grazing of sheep. It is necessary to evaluate, identify and quantify the chemical compounds of selected vegetal species because these can act as nutritional bio-indicators and potential in sheep feeding.