@article {JRN55160, title = {Synthesis paper: Targeted livestock grazing: Prescription for healthy rangelands}, journal = {Rangeland Ecology and Management}, volume = {72}, year = {2019}, month = {11/01/2019}, abstract = {Targeted livestock grazing is a proven tool for manipulating rangeland vegetation, and current knowledge about targeted livestock grazing is extensive and expanding rapidly.\  Targeted grazing prescriptions optimize the timing, frequency, intensity, and selectivity of grazing (or browsing) in combinations that purposely exert grazing/browsing pressure on specific plant species or portions of the landscape.\  Targeted grazing differs from traditional grazing management in that the goal of targeted grazing is to apply defoliation or trampling to achieve specific vegetation management objectives, whereas the goal of traditional livestock grazing management is generally the production of livestock commodities.\  A shared aim of targeted livestock grazing and traditional grazing management is to sustain healthy soils, flora, fauna, and water resources that, in turn, can sustain natural ecological processes (e.g., nutrient cycle, water cycle, energy flow).\  Targeted grazing prescriptions integrate knowledge of plant ecology, livestock nutrition, and livestock foraging behavior. Livestock can be focused on target areas through fencing, herding, or supplement placement.\  Although practices can be developed to minimize the impact of toxins contained in target plants, the welfare of the animals used in targeted grazing must be a priority.\  Monitoring is needed to determine if targeted grazing is successful and to refine techniques to improve efficacy and efficiency.\  Examples of previous research studies and approaches are presented to highlight the ecological benefits that can be achieved when targeted grazing is applied properly. These cases include ways to suppress invasive plants and ways to enhance wildlife habitat and biodiversity.\  Future research should address the potential to select more adapted and effective livestock for targeted grazing and the associated animal welfare concerns with this practice.\  Targeted livestock grazing provides land managers a viable alternative to mechanical, chemical, and prescribed fire treatments to manipulate rangeland vegetation.}, keywords = {focused grazing, livestock, prescriptive grazing, rangelands, targeted grazing, vegetation manipulation}, doi = {10.1016/j.rama.2019.06.003}, url = {bibliography/19-024.pdf}, author = {C. Donovan Bailey and J. C. Mosley and Richard E. Estell and Andr{\'e}s F. Cibils and M. Horney and John Hendrickson and J.W. Walker and Launchbaugh, K.L. and Burritt, E.A.} } @article {JRN54922, title = {Controlling one-seed juniper saplings with small ruminants: What we{\textquoteright}ve learned}, journal = {Rangelands}, volume = {40}, year = {2018}, month = {10/2018}, pages = {129-135}, chapter = {129}, abstract = {

Protein supplements and polyethylene glycol increased juniper intake by small ruminants in all seasons except fall, when PSM concentrations were greatest. Terpenes were affected by season and sapling size, and were related to juniper intake by small ruminants. Small sapling browsing occurred most frequently in summer. Debarking of branches on taller saplings was greatest in spring. Ten years later, juniper kill ranged from 5-14\%. Growth suppression was still evident after 10 years; browsed saplings averaged 13 cm shorter than controls. Strategies to target grazing of one-seed juniper are more likely to succeed if aligned with periods when PSM are lowest.

}, keywords = {goats, phenology, plant secondary metabolites, protein supplementation, sheep, targeted grazing}, doi = {doi.org/10.1016/j.rala.2018.07.002}, url = {/files/bibliography/18-018.pdf}, author = {Richard E. Estell and Andr{\'e}s F. Cibils and S. A. Utsumi and Stricklan, D. and Butler, E. M. and Fish, A. I. and Amy Ganguli} } @article {JRN53927, title = {Is differential use of Juniperus monosperma by small ruminants driven by terpenoid concentration}, journal = {Journal of Chemical Ecology}, volume = {40}, year = {2014}, month = {02/2014}, pages = {285-293}, chapter = {285}, abstract = {

We examined the relationship between volatile plant secondary metabolite concentrations and Juniperus monosperma herbivory by small ruminants. Two groups of animals (10 goats or 5 goats plus 4 sheep) browsed 16 paddocks (20 x 30 m) containing one-seed juniper for six days during two seasons. Juniper leaves were sampled from 311 saplings on the same day they were browsed. Saplings were categorized by size (short [\< 0.5 m], medium [0.5-1.0 m] or tall [\> 1.0 m]) and browsing intensity (light [\< 33\%], moderate [33-66\%] or heavy [\> 66\%]). Juniper bark was also collected from 12 saplings during spring. Total estimated terpenoid concentrations in leaves and bark were 18.3 \± 0.3 and 8.9 \± 0.8 mg/g, respectively, and the dominant terpene in both tissues was a-pinene (11.1 \± 0.2 and 7.6 \± 0.7 mg/g, respectively). Total terpenoid concentration was greater (P \< 0.001) in spring than summer (20.6 \± 0.5 vs. 16.7 \± 0.3 mg/g, respectively) and lower (P \< 0.001) in short saplings than medium or tall saplings (16.5 \± 0.6 vs. 19.8 \± 0.4 and 19.5 \± 0.4 mg/g, respectively). Total concentration also differed (P \< 0.001) among the three defoliation categories (16.1 \± 0.4, 18.7 \± 0.5, and 21.2 \± 0.6 mg/g for heavy, moderate, and light, respectively). The smallest subset of terpenes able to discriminate (P \< 0.001) between heavy and light browsing intensity categories included eight compounds ([E]-\ß-farnesene, bornyl acetate, \&$\#$39;-eudesmol, endo-fenchyl acetate, y-cadinene, a-pinene, cis-piperitol, and cis-p-menth-2-en-1-ol).

}, keywords = {goats, herbivory, one-seed juniper, Oxygenated terpenes, Resource availability hypothesis, sheep, targeted grazing, terpenes}, doi = {10.1007/s10886-014-0389-1}, url = {/files/bibliography/14-006.pdf}, author = {Richard E. Estell and S. A. Utsumi and Andr{\'e}s F. Cibils and D.M. Anderson} } @article {JRN52689, title = {Manipulating sheep browsing levels on Coyote Willow (Salix exigua) with supplements}, journal = {Sheep and Goat Research Journal}, volume = {25}, year = {2010}, pages = {32-38}, chapter = {32}, abstract = {

Macronutrients and additives have been used to suppress or promote intake of upland tannin-containing browse species by livestock, but to our knowledge this technique has not been applied to sheep that feed on tannin-containing species in riparian areas. The objective of this study was to determine the effect of four supplement regimes on coyote willow (Salix exigua) intake by sheep during the dormant and growing seasons. Twelve Western White Face lambs (48 \± 4.5 kg) were placed in individual pens and assigned to one of four treatments which consisted of a basal diet of sudangrass and supplements predicted to either suppress (whole corn or quebracho tannin) or promote (cottonseed meal or polyethylene glycol, PEG) willow intake. Each of the four supplements was tested with dormant and growing willow in a Latin rectangle design with 3 periods and 6 lambs per group. Basal diet (sudangrass) intake was affected by neither promoter nor suppressor treatments in either season. Cottonseed meal effectively promoted intake of willow compared to the control and PEG treatments (P\< 0.05) in the dormant season. No difference was detected between the control, quebracho tannin, and whole corn treatments, although the latter tended to depress dormant willow intake of lambs. None of the treatments altered intake of coyote willow in the growing season trials. Protein and possibly corn-based supplements may be effective tools to manipulate sheep browsing levels of Salix exigua but need to be tested in a field setting before management strategies with supplementation can be applied.

}, keywords = {cottonseed meal, polyethylene glycol, quebracho tannin, tannins, targeted grazing, whole corn}, url = {/files/bibliography/10-031.pdf}, author = {Lujan, Adam L. and S. A. Utsumi and Smallidge, S.T. and Terrell T. Baker and Richard E. Estell and Andr{\'e}s F. Cibils and S. Ivey} } @article {50063, title = {One-Seed Juniper Sapling Use by Goats in Relation to Stocking Density and Mixed Grazing With Sheep}, journal = {Rangeland Ecology \& Management}, volume = {63}, number = {3}, year = {2010}, note = {doi: 10.2111/08-215.1}, pages = {373-386}, publisher = {Society for Range Management}, 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.}, keywords = {diet mixing, grazing systems, targeted grazing, uniper control}, isbn = {1550-7424}, doi = {10.2111/08-215.1}, url = {http://handle.nal.usda.gov/10113/58280}, author = {S. A. Utsumi and Andr{\'e}s F. Cibils and Richard E. Estell and Terrell T. Baker and J.W. Walker} }