One-seed juniper use by goats: Influence of stocking density and mixed grazing in summer and spring

TitleOne-seed juniper use by goats: Influence of stocking density and mixed grazing in summer and spring
Publication TypeConference Paper
Year of Publication2008
AuthorsUtsumi S.A., Cibils AF, Estell R.E., Walker J.
Conference NameSociety for Range Management Annual Meeting
Date PublishedJanuary 26-31, 2
Conference LocationLouisville, KY
ARIS Log Number215586
Keywordsabstract, abstracts, density, juniper, one-seed

Targeted grazing with goats could be used to suppress one-seed juniper (Juniperus monosperma) sapling invasion if suitable grazing techniques are identified and applied. We examined the effects of stocking density and mixed grazing with sheep on utilization of herbaceous vegetation and juniper saplings (< 2m) by Boer-Spanish goats in summer and spring. The study was a 2x2 factorial with two herbivores and two stocking densities. Ten goats (Goats alone) or five nannies mixed with four Rambouillet ewes (Mixed grazing) were placed in 10x10 m plots for one day (High Density) or 20x30 m plots for six days (Low Density). Stocking rate for both treatments was 1.1 AU/ha/yr. There were two complete blocks in each season. Time spent feeding on juniper (TFJ; %) and utilization of herbaceous vegetation (UHV; %) were determined. There were no differences in TFJ (P=0.99) nor UHV (P=0.27) between seasons. TFJ varied by herbivore and density treatment (herbivore x density: P = 0.16). Goats spent more time feeding on juniper in high vs. low stocking density treatments (P=0.01), although differences in TFJ among stocking density treatments were larger in mixed grazing plots (34.4 vs. 17.7% ± 3.5) than in plots where goats grazed alone (28.2 vs. 22.2% ± 3.6). UHV was higher in low vs. high stocking density plots (67.0 vs. 59.6% ± 2.3; P=0.05) and in plots with mixed grazing vs. goats grazing alone (69.8 vs. 56.9% ± 2.4; P<0.01). High density grazing and mixed grazing with goats and sheep can increase the use of juniper by goats. Low density grazing appears to encourage selective grazing which results in more intensive use of herbaceous understory. Overall, stocking density and mixed grazing are two promising techniques to manipulate juniper and herbaceous plant utilization in targeted grazing programs with goats.