Influência da estrutura da vegetação na seleção da dieta de ovinos em pastejo, em área de cerrado

Abstract

Floristic and phytosociological surveys indicate the appropriate management of the various existing biomes, as well as they result in agroecological strategies to determine the diet of ruminants. The objective of this research was to characterize the vegetation in an area of cerrado in the north of Minas Gerais and to evaluate the composition of the diet selected by ovine grazing in this area. To survey the species was carried out in 1,52 ha and used the method of parcel. To shrub-arboreous species 20 m × 20 m. To the stratum regenerating 5 m × 5 m. To the herbaceous were performed two transects, with 283 points each (566 m). In each two meters, was released to the ground a square of 0,50 m × 0,50 m, where species within the delimitation of the square were collected. Were sampled 1288 arboreous individuals, 102 regeneranting and 1395 herbaceous, grouped in 94 vegetal species distributed in 72 genus and 33 botanical families.The characterization of the diet of ruminants was performed using the feeding behavior of three sheep and evaluated through the selectivity index, during the dry and rainy season between the months of April of 2009 and March of 2010. The observation of the feeding behavior of the species selected by animals, allowed that they be collected in natura and identified. The species Andropogon sp., Baccharis tridentada, Casearia sylvestris, Paullinia sp., Schinopsis brasiliensis and Ximenia americana showed high levels of selectivity, due to time and quantity of the resource in the area. The selected species with frequency Evolvulus sp., Erythroxylum deciduum, Heteropterys byrsonimifolia and Stylosanthes spp., Lippia sidoides and Senna sp., are important for the proper management of vegetation, by the high availability of the same in the area. These species are determinant in the concentration of studies, because they provide the maintenance of the cerrado, and can act as nutritional and potential bioindicators in the feeding of ruminants.