Phytobezoars are structures formed by the aggregation of primarily plant fibers in the digestive tract of ruminants, causing intestinal obstruction that can lead to the death of an animal. Information about the formation of these clusters is scarce. This study identified the main components of bovine phytobezoars and described the leaf anatomy of three species and one variety of Stylosanthes SW.: S.capitata Vogel, S. macrocephala B. Ferreira & S. Costa, S. guianensis var. vulgaris M.B. & Sousa Ferreira Costa cv. 'Mineirão' and S. guianensis (Aubl.) Sw. These plants are used as feed for livestock and probably contribute to the formation of phytobezoars. The phytobezoars were fragmented for analysis of their internal composition and were studied according to plant anatomy techniques. The fibers and crystals found in phytobezoars were similar to the sclerenchyma fiber bundles found in Stylosanthes. The comparative analysis of Stylosanthes showed differences in the abundance of fibers in the leaflets of each species. S. macrocephala is the variety that may have the highest potential for formation of phytobezoars in the digestive tract of animals because there was an abundance of fibers and crystals present in the leaf. The sclerenchyma bundles, idioblasts, and the abundance of calcium oxalate crystals in Stylosanthes species may potentiate the formation of phytobezoars in ruminants, particularly when these legumes are consumed in excess.
intestinal obstruction; fibers; legumes; Stylosanthes