G. Castellaro G., H. Urra A., J. Hidalgo A., C. Orellana M., and J. Escanilla C. 2018. Sheep
and goat grazing diets on an annual Mediterranean grassland containing tall wheatgrass
(Thinopyrum ponticum (PODP.)). Cienc. Inv. Agr. 45(3):240-250. The development of mixed
grazing systems is an interesting alternative for the utilization of rangelands with ecological and/
or economic limitations; therefore, the study of patterns and eating habits of different species in
the same grazing area is important. A mixed grazing study was carried out on a Mediterranean
grassland sown with Thinopyrum ponticum 30 years ago (Rinconada de Maipú, Chile 33º 28’S;
70º 51ʼ W) with the purpose of quantifying the botanical composition, dietary overlap and
selectivity indexes of the main grass species consumed by goats and sheep. Trophic behavior was
studied in seven young Suffolk Down rams, seven young Merino-Precoz rams and seven young
Boer-Criollo bucks grazing together during three grassland phenological stages. During the
grassland vegetative stage, diets were mainly composed of annual grasses and forbs. Perennial
grasses dominated the animals’ diets during the reproductive and dry grassland stages. The
diversity of the goats’ diets was higher than that of the sheep, demonstrating greater plasticity
in their dietary habits. However, in this environment, both species behaved as generalist
herbivores. The level of diet overlap between the sheep and goats was high, especially when
grazing during the grassland reproductive and dry phenological stages, suggesting potential
competition during lower forage quality stages.