Efecto del pastoreo mixto Ovino-Bovino en la selección de herbáceas en sabanas bien drenadas en Venezuela

The production systems with ruminants in Venezuela are characterized by the management of grazing animals, where sheep and cattle have been incorporated simultaneously or alternately, which has been done without basic scientific information to support management decisions at the level of farms. Animal resource was conformed by crossbreed Brahman weaned calves (live weight (LW) 140.05 ± 0.78 kilograms (kg)) and 6 West African lambs (LW 23.60 ± 0.37 kg). The selection of herbaceous was determined by microhistologycal analysis, in samples of feces weekly, dur- ing four weeks. The relative frequencies of the botanical species identified in feces were analyzed by Kruskal-Wallis test, as a com- pletely randomized design. Relative density showed a higher numerical participation of Trachypogon spicatus (L.f.) Kuntze (17.62 %) and Trachypogon vestitus Andersson (17.33 %), and the highest relative frequencies for Trachypogon vestitus Andersson (9.85 %) and Trachypogon spicatus (L.f.) Kuntze (8.68 %). Selection of herbaceous was different (P<0.01) between animal species, with a high frequency of legumes in ovine feces, with Desmodium spp. and Mimosa albida Willd. as predominant species. Herbaceous species had the highest frequency in bovines, with Trachypogon vestitus Nees and Axonopus spp. as predominant. Differences indicate that mixed and continuous grazing, with a ratio of 1:1 (ovine: bovine) can contribute to an integral selection of forage native in well drained savannas.