Goats for noxious and invasive weeds in Montana• Underbrush removal •Pasture recovery
Using goats to control noxious and invasive weeds
Control Leafy Spurge with goats
Goats can be a viable option for controlling leafy spurge — a noxious and invasive weed in Montana and neighboring states.
A four year study evaluated pairing goat grazing and herbicide control (picloram plus 2,4-D) as a better long term control leafy spurge (Euphorbia esula L.) infestations than either treatment alone. Six treatment combinations (untreated control, goat grazing only, fall herbicide only, spring herbicide only, goat grazing following spring herbicide, and goat grazing prior to fall herbicide application) were tested on two locations in eastern North Dakota.
This article summarizes some of the results from a study on leafy spurge.
The orchard had been untouched for 15 years prior. Grazing intensities: 30 does per acre for goats only, 17 does / ha + 2-3 steers / ha for combined grazing treatment.
• A single year of defoliation did not yield a reduction in density of leafy spurge stems.
• Population and growth of the weed decreased significantly (55% reduction in stem densities) when the defoliation occurred twice during the growing season for four consecutive years.
• Grass cover and production increased at all levels of defoliation.
• Density of leafy spurge stems was decreased in twice-defoliation treatments to levels that would not deter cattle grazing.
Annotation: This study demonstrates that control of leafy spurge may be obtained by any of the methods tested but speed and long term control vary greatly. NRCS recommended stocking rates for this overflow range site are 2.4 AUM/ha. The study used stocking rates of 2.1, 2.8 and 2.9 AUM/ ha.
Summary of Methods: Two ungrazed control plots, two grazed by goats and two grazed by a combination of goats and cattle were established in an overgrown abandoned orchard to study rehabilitation of herbaceous species and control of encroaching undesirable species. No major differences were found between the two grazing treatments; percent cover and herbaceous grasses increased in the two grazing treatments because of the defoliation of the shading overstory of brush, trees and multiflora rose bushes (Rosa multiflora). Bluegrass (Poa pratensis), tall fescue (Festuca arundinacea), white clover (Trifolium repens) and Nimblewill (Muhlenbergia schreberi) increased, while poison ivy (Toxicodendron radicans), brambles (Rubus), and honeysucke (Lonicera japonica) decreased.
Wild strawberry and mint (mentha) increased in the goats-only treatment. Goats were effective in controlling multiflora roses, killing 100% and 92% and of canes in 2.5 years, although new sprouted shoots were observed following two years of rest. Results indicated that the foraging habits of goats resulted in the elimination of multiflora rose bushes and in a significant increase in desirable forage species. This study in North Carolina was conducted over a four year period to evaluate the effects of three grazing regimes (goats alone, goats and cattle, and no grazing) in a pasture rested for 15 years and overgrown with multiflora rose (Rosa multiflora Thumb.) Herbaceous vegetative cover increased with goat grazing alone (from 65 to 86%) and with goat and cattle grazing (from 65 to 80%), while the control plots yielded a decrease (from 70 to 22%). The percent cover by grass species had a similar response.
Multiflora rose bushes experienced an average reduction in height from 2.1 meters to 0.6 meters, nearly eliminating it from the grazed pastures. The number of dead multiflora rose stems were 100% and 92% in the goats grazing alone and goat and cattle grazing, respectively. Authors conclude that grazing is an effective tool for the elimination of multiflora rose, at the same time increasing the abundance of desirable forage species.
Leafy spurge along the Missouri River National Monument in Montana (photo by David Reese/Montana Goat Co.)