Prairie dogs alter vegetation structure and composition on their colonies by continuously clipping it to short stature. Alteration of structure and composition likely influences diet selection and therefore nutrition of grazing cattle, but this relationship is poorly understood. Our objective was to compare rate of digestion of diets of cattle grazing either on- or off-colonies of prairie dogs. In 2013, 6 ruminally cannulated steers grazed 4 pastures that were partially colonized by prairie dogs. Steers were used to collect diet samples for nutrient analysis from temporary enclosures in 3 locations in the pastures: annual-plant-species dominated core of PD colonies, grass-dominated portion of PD colonies, and off-PD colony. Diet samples were collected monthly in June, July, and August. Diet samples were lyophilized, ground to pass a 2-mm screen, and composited across pasture and steers to create location by month composites. In 2014, the composite diet samples were subjected to in-situ incubation in 2 of the same steers grazing the same pastures. A first-order disappearance model was used to determine rate of degradation. Influence of advancing plant maturity as the grazing season progressed on differences in rate of degradation among on- and off-prairie dog colony locations will be discussed. Rangelands with a mosaic of on- and off-prairie dog colony locations appear to provide the opportunity for grazing cattle to select diets that optimize nutrient intake.
Oral presentation and poster titles, abstracts, and authors from the Society for Range Management (SRM) Annual Meetings and Tradeshows, from 2013 forward.