Sheep and goats as tool to suppress juniper encroachment: Influence of stocking density and mixed grazing during summer

TitleSheep and goats as tool to suppress juniper encroachment: Influence of stocking density and mixed grazing during summer
Publication TypeConference Paper
Year of Publication2007
AuthorsUtsumi S., Cibils AF, Estell R.E.
Conference NameSociety for Range Management Annual Meeting
Date PublishedFebruary 9-16, 2
Conference LocationReno/Sparks, NV
ARIS Log Number210224
Keywordsgoats, grazing, one-seed juniper, sheep
AbstractGrazing trials were conducted to evaluate the use of prescribed grazing by sheep and goats to suppress one-seed juniper (Juniperus monosperma Englem. Sarg.) sapling reinvasion. A 2x2 factorial experiment was conducted with Goats (G) or Goats + Sheep (G+S) at high or low stocking densities (SD). Ten crossbreed Angora nannies (1.1 AU) or 5 nannies of the same breed mixed with 4 Ramboullet ewes (1.1 AU) grazed either 1 juniper invaded plot of 20 x 30 m for 6 days (LD) or 6 similar subplots of 10 x 10 m for 1 day (HD) in each of 2 blocks. Animals grazed from sunrise to sunset, were penned at night and received a protein supplement (45% CP) at a rate of 0.4% BW, daily. No effect of SD, herbivore (G, G+S), or their interaction was found on juniper utilization. Animals removed on average 38.3% of the length of marked juniper sapling branches. Understory grazing intensity differed between G or G+S (P=0.02) and SD (P=0.05) treatments. G+S removed 71.3 % of the available herbaceous biomass whereas G removed 64.7 %. Greater understory grazing intensity was observed under LD (70.4 %) compared to HD (65.0 %). Goats spent more time feeding on juniper compared to sheep (Goats: 24.5%, Sheep: 7.7%, P