Range Management Research Site Logo
ARS Home About Us Helptop nav spacerContact Us En Espanoltop nav spacer
Printable VersionPrintable Version     E-mail this pageE-mail this page
Agricultural Research Service United States Department of Agriculture
Search
  Advanced Search
 
Programs and Projects
Subjects of Investigation
Ecological Site Descriptions
Monitoring & Assessment
Long Term Ecological Research
Long Term Agricultural Research
Landscape Toolbox
Data Catalogs
EcoTrends
 

Research Project: MANAGEMENT TECHNOLOGIES FOR ARID RANGELANDS

Location: Range Management Research

Title: One-seed juniper sapling use by goats in relation to stocking density and mixed grazing with sheep

Authors
item Utsumi, Santiago -
item Cibils, Andres -
item Estell, Richard
item Baker, T -
item Walker, J -

Submitted to: Rangeland Ecology and Management
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 4, 2010
Publication Date: May 15, 2010
Citation: Utsumi, S.A., Cibils, A.F., Estell, R.E., Baker, T.T., Walker, J.W. 2010. One-seed juniper sapling use by goats in relation to stocking density and mixed grazing with sheep. Rangeland Ecology and Management. 63:373-386.

Interpretive Summary: Encroachment of shrubs such as one-seed juniper into rangelands is a serious problem for livestock producers. A study was conducted to determine if small ruminants could be used in targeted grazing strategies to suppress sapling growth of junipers. Because domestic livestock typically avoid feeding on juniper, this study examined approaches to increase shrub browsing intensity to levels that would damage sapling growth without permanently affecting the grass understory. Goats and mixed species (goats plus sheep) were examined during summer and spring at two stocking densities. Animals tended to remove needles and small stems from small saplings, while debarking was the main impact on taller plants. High density stocking by goats led to increased feeding time on juniper saplings compared to goats in low density stocking. Mixed species high-density stocking resulted in the highest proportion of small saplings exhibiting high defoliation. Herbaceous vegetation use was greater with mixed-species that with goats alone, and greater with low density than high density stocking. Both stocking density and mixed-species grazing can be used to alter feeding behaviors that increase utilization of juniper saplings by goats.

Technical Abstract: To successfully suppress reinvasion of one-seed juniper (Juniper monosperma [Englem.] Sarg.) with goats, defoliation of newly established saplings must be enhanced to levels that eventually kill or suppress plant growth. We tested the effect of stocking density and mixed grazing with sheep as potential grazing strategies to increase utilization of one-seed juniper saplings by goats. In summer and spring, groups of 10 does (Goats alone, GA) or 5 does and 4 ewes (Mixed grazing, MG), grazed 20 x 30 m cells infested with saplings (500-533/ha; 0.8 m tall), either continuously for 6 days (Low stocking density, LD) or with daily rotation through 10x10m cells during the 6 day period (High stocking density, HD) in a block design. Frequency of saplings with light, moderate and heavy bark and foliage use, feeding activity, juniper in feces, and utilization of herbaceous vegetation were determined. Goats in HD treatment spent more time feeding on saplings, less time feeding on herbaceous forages, and tended to achieve diets with more juniper than goats in LD. Utilization of herbaceous vegetation ranged from 52 to 73% and was higher for MG than GA and for LD than HD. The MG-HD treatment resulted in highest frequency of short saplings (< 0.5m) with high percent (> 66%) of defoliated branches in summer and spring, and lowest frequency of saplings with low percent (< 33%) of debarked branches in spring. Heavy defoliation was more frequent in shorter saplings, whereas heavy debarking occurred mostly in tall saplings. The results of this study suggest that stocking density and mixed grazing stimulate feeding behaviors that increase utilization of juniper saplings by goats.

   

 
Project Team
Estell, Richard - Rick
Lucero, Mary
Peters, Debra - Deb
Havstad, Kris
Rango, Albert - Al
Herrick, Jeffrey - Jeff
Anderson, Dean
Bestelmeyer, Brandon
 
Publications
   Publications
 
Related National Programs
  Pasture, Forage and Rangeland Systems (215)
 
 
Last Modified: 05/25/2013
ARS Home | USDA.gov | Site Map | Policies and Links 
FOIA | Accessibility Statement | Privacy Policy | Nondiscrimination Statement | Information Quality | USA.gov | White House