POTENTIAL FOR WOODY PLANT CONTROL BY SPANISH GOATS IN THE SAGEBRUSH STEPPE

Botanical composition of the diet of eight Spanish goats was studied o n the Northern Great Basin Experimental Range during two stages of pla nt phenology (active growth in early July and cured forage in mid-Augu st) to assess their potential for the control of sagebrush (Artemisia tridentata sspp, wyomingensis Nutt.) and western juniper (Juniperus oc cidentalis Hook.) and their nutritional status on sagebrush-steppe ran gelands. Diets were quantified by documenting the number of visits to each species, the bites harvested and time expended prating each forag e over 4 consecutive days in each period, Forage chemical characterist ics evaluated included: CP, NDF, ADF, ADL and IVDMD, Diet composition and forage quality indices varied significantly (P < 0.05) with change s in plant phenology. Vegetation cover averaged 52% in the pasture and consisted of 36% grasses, 8% forbs, 7% shrubs and 0.6% trees, Availab le herbage (excluding woody plants) was 534 kg ha(-1) during active gr owth trials and 572 kg ha(-1) when forages had cured. When forages wer e green goats acquired 28% of their total bites from grasses, 71% from forbs, 0.3% from shrubs and 0.9% from juniper trees. After forages ha d cured values were 35% from grasses, 56% from forbs, 0.1% from shrubs and 8.8% from juniper. The browsing of juniper (both foliage and bark ), after herbaceous forages had cured, was the only substantive use of woody plants, Sagebrush was only lightly used (0.2% of total bites) w hen herbaceous forages were actively growing. Available herbage was of relatively high quality during both trials. When forages were activel y growing; CP of grasses ranged from 8.9 to 5.6%, forbs from 17.7 to 8 .5%, sagebrush scored at 8.5%, juniper foliage at 8.1% and juniper bar k at 3.2%. After herbaceous forages had cured, grass CPs ranged betwee n 6.2 and 3.1%, forbs from 10.4 to 4.4%, shrubs were not sampled and j uniper foliage averaged 7.6%, Given the low levels of browsing exhibit ed by goats on sagebrush and juniper we see little opportunity for con trol of these woody plants when pastures provide a diverse (N = 25 spe cies) array of readily available (534-572 kg ha(-1)) and nutritious fo rages and pastures are lightly stocked (0.63 goats ha(-1) month(-1)). We do need, however, to further explore their potential for control of these species under several other regimes. These include extended tri als on more deteriorated rangelands, trials during seasons or conditio ns where forage is limited and the animal's selective opportunity is r estricted and trials in high quality environments on newly established sagebrush and juniper seedlings.