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Diets of Rambouillet, Karakul, and Barbado sheep (Ovis aries) and Spanish and Angora goats (Capra hircus) grazing in 3 plant communities in western Texas were determined by microhistological analysis of fecal samples. Grasses were commonly the major foods of all sheep breeds as well as Angora goats. Forbs were major diet items of all breeds of sheep and goats when they were readily available. Spanish goats, and to a lesser extent Angora goats, relied heavily on browse. Barbado sheep consumed more browse than did Rambouillet or Karakul sheep. Diets of Rambouillet and Karakul sheep overlapped considerably, whereas diets of Rambouillet sheep and Spanish goats were quite dissimilar. Barbado sheep appeared to occupy a food niche intermediate between that of the goats and the other sheep breeds. Spanish and Angora goats exhibited the strongest tendency and Karakul sheep exhibited the least tendency to selectively graze. Neither Barbado nor Karakul sheep consumed sufficient amounts of undesirable shrubs to be considered valuable for brush suppression.

Microhistological analysis of feces from Spanish goats (Capra hircur) grazing in a mixed-brush complex in the South Texas Plains indicated that shrubs were their major foods during autumn, winter, and summer. Grasses were the major diet item during spring. Forbs, which were relatively scarce due to poor growing conditions during the U-month study, were of minor importance in goat diets. The importance in Spanish goat diets of several problem brush species, including blackbrush acacia (A cacia rigidula), condalias (Condalia spp.), guajillo (Acaeio bertimdieri), guayacan (Porliera angust~ofia), and wolfberry (Lycim berlandini) suggests a potential for utilizing these animals in conjunction with other brush management practices for more effective shrub control and for increasing efficiency of forage utilization on mixed-brush rangeland.The South Texas Plains are approximately 8 million ha which historically supported grassland or Savannah type vegetation (Thomas 1975). Long-term continuous grazing, periodic droughts, and the reduced frequency and intensity of fires have resulted in a

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Silvex alone or with 2,4-D in a 1:l ratio at about 3 to 4 kg/ha gave 60 to 10% control of many brush species including poison oak, Oregon oak, and maples. Picloram at 1 kg/ha plus 2,4-D at 4 kg/ha was most effective with respect to the amount of picloram; however, the mixture of 1 kg/ha plus 2 kg/ha respectively, was nearly as good. Complete pasture renovation in this area requires brush control, burning, fertilization, and seeding of desirable species. Picloram and 2,4-D disappear from soils in 29 months with no significant leaching into the soil profile at these study sites. Herbicide discharge in streamflow was small, representing 0.35% and 0.014% of applied picloram and 2,4-D. We believe that nearly all of the herbicide discharged from these watersheds represents residue deposited in dry stream channels or that mobilized by fall rains from adjacent streambanks. Significant overland movement of herbicides from upslope did not occur on these study areas. The probability of crop damage from irrigation with water from these watersheds is low.