• Dietary Selection and Nutrition of Spanish Goats as Influenced by Brush Management

      Lopes, E. A.; Stuth, J. W. (Society for Range Management, 1984-11-01)
      Botanical composition of Spanish goat diets was only different when diets selected from tebuthiuron-treated pastures were compared to those from untreated and mechanically treated areas in the Texas Post Oak Savannah. However, all brush management treatments significantly affected the browse component in summer diets. Diets selected from untreated and mechanically treated pastures were dominated by browse, while grasses and grasslike plants occurred most in diets selected from the tebuthiuron-treated plots. Yet, during fall and winter, vines comprised the bulk of diets collected on these areas. Forbs were a minor dietary component. Goat diets from untreated and mechanically treated pastures consistently shifted from browse to grasses and grasslike plants as seasons advanced. Selection of grasses and grasslike plants on tebuthiuron-treated pastures declined sharply from summer through winter and increased through spring. Similar but inverse trends occurred in respect to vines and browse. Mean levels of crude protein (CP) in diets selected by esophageally fistulated goats grazing chemically treated pastures were significantly greater than in diets from the other pastures in winter and spring. In summer and fall, dietary forage material from all pastures contained equivalent levels of crude protein. Dietary in vitro digestible organic matter (IVDOM) was higher in summer and winter from tebuthiuron-treated pastures compared to mechanically treated and untreated areas. In fall, diets from tebuthiuron-treated pastures were higher in IVDOM content than those from untreated ones but were similar to diets from mechanically treated pastures. However, in spring all pastures receiving brush management yielded diets with higher IVDOM content than brush-treated areas. In general, methods of brush control had greater effects on IVDOM than on CP contents of diets.
    • Estimating Seasonal Diet Quality of Pronghorn Antelope from Fecal Analysis

      Koerth, B. H.; Krysl, L. J.; Sowell, B. F.; Bryant, F. C. (Society for Range Management, 1984-11-01)
      Botanical composition of pronghorn antelope diets from fecal analysis and nutrient quality of samples of plants known to be used by pronghorn were evaluated from June 1979 to May 1980 in Oldham and Hartley counties of the Texas Panhandle. Pronghorn in this area consume forbs primarily throughout the year, followed by browse and grasses. Pronghorn exhibited an affinity for either Artemisia ludoviciana or Sphaeralcea coccinea, or both, in all seasons. Grass use was negligible. Seasonal crude protein estimates ranged from a low of 9.8% in winter to a high of 11.4% in spring. Estimates of phosphorus were lowest in winter (0.15%) and highest in spring (0.18%) corresponding to rapid plant growth. Digestible energy levels were lowest in the fall, approaching 2,227 kcal/kg, and highest in spring and summer, 2,656 and 2,631 kcal/kg, respectively. Average in vitro digestible organic matter coefficients for spring, summer, fall, and winter were 69%, 67%, 53%, and 61%, respectively. The combination of fecal analysis for botanical composition and nutrient content from samples of plants known to be ingested provides at least an estimate of nutrient content of the diet.