We studied use of pastures and habitats in relation to moderate cattle grazing for 19 radio-collared desert mule deer (Odocoileus hemionus crooki) in a southeastern Arizona grass-shrubland. For each deer, use of grazed or ungrazed pastures and habitats in relation to their availability within the deer's home range was tested on a seasonal and annual basis. Deer, especially females during summer, tended to use currently ungrazed portions of their home range and dry wash habitats more than expected. Most deer showed a strong preference for ungrazed dry wash habitats, followed by grazed dry washes and ungrazed uplands. Although deer used grazed uplands less than expected based on availability, deer were still observed frequently in this abundant type. Deer use of currently ungrazed habitats may have been due to absence of cattle or to effects of recent cattle grazing in these habitats. During 2 years of favorable precipitation and forage conditions deer appeared to be adjusted to moderate rest-rotation cattle grazing. Leaving some areas periodically ungrazed might also provide a contingency for deer against impacts of cattle grazing during drought.

Freeze drying, conventional oven drying, and microwave oven drying were compared with respect to their effect on the chemical composition of native range forage and feces from cattle grazing the forage. Forage was collected by hand harvesting and by esophageal-fistulated steers (extrusa) on 10 collection dates from 11 June to 15 Oct. in 1987 and on 6 collection dates from 2 June to 15 Sept. in 1989. Composite fecal samples were obtained from cattle grazing the same pastures the day following forage collections. Drying method had minimal effect on in vitro digestible organic matter (IVDOM), ash, neutral detergent fiber (NDF), nitrogen, and ash insoluble in neutral detergent (AIND) in hand clipped native forage. However, both microwave and conventional oven drying of extrusa resulted in greater NDF than freeze drying. Unexpectedly, IVDOM in microwave oven dried extrusa was equal to or greater than values for freeze dried material. There were no interactions between drying method and sampling date for any components measured in the extrusa. Microwave and conventional oven drying of feces resulted in greater NDF values than freeze drying, with microwave drying resulting in significantly greater NDF than conventional oven drying. There was also more AIND in heat dried feces, but nitrogen and ash levels were not affected by drying method. The data indicate that if nitrogen or ash are to be determined in hand cupped forage, extrusa, or feces, then microwave or conventional oven drying is acceptable; but if fiber levels are to be determined in these materials, then it appears they should be freeze dried for the most accurate results.