- Animals: goats
- Animal Production: grazing management, grazing - rotational
- Education and Training: demonstration
- Natural Resources/Environment: biodiversity, habitat enhancement
The removal of fire and native grazers, coupled with consequent shrub and tree encroachment, has resulted in oak savannas and woodlands becoming some of the rarest ecosystems in the Midwest (Henderson 1995). Restoring and maintaining these open structured communities can be difficult for private landowners on whose land the majority of these remnants occur (Henderson & Epstein 1995). However, this presents an opportunity for simultaneous livestock production and habitat conservation. Managed grazing with cattle can be an effective, but logistically difficult tool for managing woody brush in oak communities (Harrington & Kathol 2009). This study looks at pasturing meat goats in a shrub-infested oak woodland in southwest Wisconsin. We explore whether rotational grazing can be used as a tool to (1) restore natural composition and structure of native vegetation forms, (2) expand grazing land opportunities for private landowners, (3) provide landowners with a profitable and accessible tool to manage their property, and (4) support conservation efforts without adverse environmental effects. This study compares two grazing regimes (light and heavy) in five replicate blocks under a rotational grazing regime. The study observes goat browse preferences and changes in goat weight and health to measure productivity. Changes in cover, density and height of shrubs, saplings and herbaceous species are measured, along with litter depth and soil compaction. We will host a field day for goat producers and land managers to discuss this potential productivity of degraded oak systems as pasturage and the use of goats as shrub control agents. The study results may suggest independent, mutually beneficial relationships between goat producers and land managers.
Project objectives from proposal:
For this project the expected short-term outcomes are that both private (ranchers and farmers) and public land managers learn about potentially profitable and mutually beneficial methods of conservation management on underutilized, ecologically degraded land. This will be accomplished through field days held on site during periods of rotational grazing to show how to incorporate goats into land management as well as to discuss treatment results and animal health. Expected intermediate outcomes are that goat producers and land managers apply rotational grazing techniques to increase pasture acreage and improve ecological quality in smaller areas. This will likely be on a smaller scale until it is established that the method works well and is productive. For long-term outcomes, we anticipate a working relationship between goat producers and land managers in which land managers provide producers with land for forage and producers provide land managers with an ecological service.
Context, Background and Rationale
This project seeks to study the application of targeted rotational grazing to restore oak-related ecosystems in southern Wisconsin. Prior to European settlement, oak communities were characterized as having a relatively open canopy and limited midstory, largely due to fire and grazing. This proposal seeks to continue a second year of study using rotational goat browse to reduce shrub and sapling densities in the restoration of degraded oak communities and in the assessment of these areas as potential pasture for goat producers. The project site is located on 30 acres within the 4,215-acre Yellowstone Wildlife Area (YWA) in Lafayette County, WI. The vegetation patterns are similar to many degraded oak savanna remnants currently being targeted for restoration. With the absence of fire and historical browse pressures the YWA canopy filled in with mesic species such as elm and basswood. In 2008, the DNR thinned the canopy to approximately 30% leaving a mix of predominantly white oak (Quercus alba) and bur oak (Q. macrocarpa). As expected, the resulting increase in sunlight led to a significant increase in shrub growth at densities too great for native groundlayer recovery. Prickly ash (Zanthoxylum americana), gray dogwood (Cornus racemosa) and brambles (Rubus spp.) are particularly dense and abundant. The invasive shrubs honeysuckle (Lonicera spp.) and multiflora rose (Rosa multiflora) also compose a substantial portion of midstory.
Most shrub-infested oak communities are only marginally utilized by farmers and land owners as they are not well-suited for either grazing or agriculture and therefore are of little economic benefit. Landowner’s solutions for managing brush in woodlots are either fire, mechanical, or chemical and each have drawbacks. Fire is a liability issue and requires significant training to apply in these settings and mechanical and chemical methods are economically and environmentally costly, need frequent repetition, and are seldom species specific (Hart 2006). Hart also notes that while chemical control costs can be $10.00 to $25.00 per acre, goats can provide a similar, bur profitable, result.
Rotational goat grazing has potential to return oak woodlands and savanna to both economic and ecological productivity. The demand for goat meat in the United States is rising primarily due to cultural preferences among a number of growing demographic groups (USDA 2005, Hart 2006). By incorporating degraded oak savanna and woodland into a rotational pasture system for meat goats, farmers could help meet growing demands while increasing the value of their underutilized acreage. Conservation management of degraded oak woodlands can also provide additional opportunities to goat producers. Government agencies and private non-profit conservation agencies that have little desire to own or market goats but wish to control brush provide opportunities for goat producers to capitalize on free grazing or expanding income sources (Hart 2006). During this study, we will monitor vegetation cover and density as well as goat health and weight to assess the economic viability of using goats to manage vegetation on lands of conservation interest.
In oak woodland and savanna restoration efforts the herbaceous understory often does not reestablish as desired. Because recovery of the herbaceous layer, particularly grasses, is dependent on seed availability, we have incorporated interseeding into this study. The establishment of these grasses is important in order to provide competition for the shrubs.
In 2002, a study was conducted on an adjacent site looking at the use of Scottish highland cattle and their effectiveness on shrub control (Harrington & Kathol 2009). The study showed that cattle grazing had a significant effect on reducing the height and density of certain species, specifically brambles, prickly ash, and hazelnut (Corylus americana). However, cattle can be logistically difficult and there are other livestock with higher browse diets. Goats are smaller animals with a higher browse diet and have the potential to provide the desired woody plant control with less understory trampling and soil compaction.
Several studies have looked at the effectiveness of goat grazing on shrub reduction, but most take place outside of the Midwest. Studies in New Zealand, Greece, Italy, Spain, and France have shown that effectively managed goat grazing can maintain original open structure of these regions (Papachristou et al. 2005a; Papachristou et al. 2005b; Ruiz et al. 2009). Goats have also been used in southern and southwestern U.S. to control unwanted vegetation, often cycling with cattle grazing regimes (Escobar 1998; Nelle 2001; Walker et al. 2006).
SARE has funded several studies exploring the effectiveness of using goats for rangeland improvement by targeting species that cattle usually don’t graze (Goetsch 2004, Hutchens 2006, Nelson 2007). Additionally, SARE has funded studies on goat grazing and noxious or invasive weed management, including a 2008 Wisconsin study in Wisconsin using goats in the reduction of buckthorn stands (Hunter, 2010). Additional studies have shown that goats can be effective at noxious or invasive weed removal (Jensen 2004, Muir 2009) but these studies again take place outside of the Midwest. Although all of these studies contribute to the knowledge and understanding of goat grazing, there is a lack of studies examining the effectiveness of goat grazing in oak savannas in the Midwest. This study intends to address that.
Approach, Activities, Methods and Inputs
Five replicate blocks were located within the 30-acre site. Each 4.5-acre block was divided into three 1.5-acre paddocks. Each paddock was randomly assigned a goat browse treatment: no browse (control), light browse (two days) or heavy browse (four days). Paddocks were also divided in half in order to fully cross browse treatments with an interseeding treatment. One half of each paddock was randomly chosen and broadcast with a native seed mix while the other half received no treatment. As interseeding may affect goat browse preference, goats will be fenced within the each half paddock. All block units are buffered with a mowed swath.
Through review of past studies and consultation with the goat provider a stocking rate of 86 goats per 1.5-acre unit was selected. Goats will be put out on both sections of a browse treatment paddock and then rotated to the next. A full rotation through all five replicate blocks takes 30 days—five two-day treatment sections plus five four-day treatment sections. Thirty to forty days later goats are rotated through the paddocks a second time. Previous studies suggest that brushy plants must be browsed as least two times in a single growing season in order for the impact to be long-term (Hart 2006). One-day and two-day treatments were used during the first rotation of the 2011 but were deemed insufficient to reduce vegetation cover. Browse treatment length was evaluated and altered accordingly for the second rotation. Results of the study’s first year show sharp reductions in foliage cover, but as anticipated limited reductions in shrub stem densities.
The results of from the 2011 season have been presented at 3 conferences, a field day, and will also be a master’s thesis. Results of this 2012 season will also be presented in a master’s thesis, in one or more peer-reviewed journals (examples are Restoration Ecology and Journal of Rangeland Ecology and Management), and at conferences and field days. Field days will target both private landowners and natural area managers while the goats are on site to demonstrate, compare, and discuss the effectiveness of browsers in private and public land management. The field day in 2011 was attended by more than 60 individuals.
Vegetative sampling will occur twice during the growing season, once in late-spring to capture spring ephemerals, pre-treatment, and once after the second goat rotation in mid-August to capture summer and fall blooming species post-treatment. Sampling will be done in the same order as the goat rotation. Nested quadrats will be used to monitor the effects of the treatments: 1-square-meter quadrats for herbaceous species; 5-square-meter quadrats for shrub/sapling density and height. Quadrats will be selected based on a stratified random design to account for the influence of slope. All trees have been previously identified, measured for DBH and mapped to obtain tree density.
Herbaceous layer will be sampled for presence/absence and relative cover using the six Daubenmire cover classes. Shrub cover will be estimated using a coverboard at a distance of 15 meters taken both directions perpendicular to the hill slope. Cover will also be assessed using the six Daubenmire classes. Shrub stem counts will be taken by species. Litter depth will also be measured in all quadrats during the second round of sampling in mid-August each year and soil compaction measurements will be obtained using a penetrometer after the last goat rotation.
All goats will be individually weighed in the spring prior to pasturing and again at the end of the summer to evaluate weight gain or loss due to foraging in a degraded savanna environment. A Famacha test to assess worm presence in goats will also be administered in the spring and then again in late summer to determine health.
Success will be evaluated by the degree and direction of change in the vegetation layers under each treatment as well as goat health. A reduction in the density and presence of shrubs and an increase in the diversity and cover of the herbaceous layer will indicate success of the treatment cycles. Weight gain in kids and no change in adults as well as no negative change in Famacha scores will indicate success of the degraded savanna as forage.
Escobar E.N. 1998. Sustainable Use of Goats as a Vegetation Management Tool. Proceedings of the National Small Farm Conference, 10-13 September, 1996. Plant and Animal Production, Protection and Processing Division of USDA-Cooperative State Research, Education, and Extension Service, Washington, D.C.
Goetsch, Arthur. 2004. Use of goats for sustainable vegetation management in grazing lands. SARE Project Number LS01-119
Harrington J.A. and E. Kathol. 2009. Responses of Shrub Midstory and Herbaceous Layers to Managed Grazing and Fire in a North American Savanna (Oak Woodland) and Prairie Landscape. Restoration Ecology 17:234-244.
Hunter, Kim. 2010. Eliminating Invasive Buckthorn with Goats, an Ecological and Habitat Restoration Study. SARE Project Number FNC08-737.
Hutchens, Terry. 2006. Goat Friendly Pastures. SARE Project Number OS03-011.
Jensen, Bonnie. 2004. Noxious Weed Grazing with Goats. SARE Project Number FW-01-039
Muir, James. 2009. Sustainable and Profitable Control of Invasive Plant Species by Small Ruminants. SARE Project Number LS05-175
Nelle S.A. 2001. Ecological Implications of Using Goats for Control of Juniper in Texas. Shrubland Ecosystem Genetics and Biodiversity, 13–15 June 2000. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station.
Nelson, Donald. 2007. Implementing Noxious Weed Control Through Multi-Species Grazing. SARE Project Number SW03-006.
Papachristou T.G., P.D. Platis and A.S. Nastis. 2005a. Foraging behaviour of cattle and goats in oak forest stands of varying coppicing age in Northern Greece Small Ruminant Research 59:181-189.
Papachristou T.G., L.E. Dziba and F.D. Provenza. 2005b. Foraging ecology of goats and sheep on wooded rangelands Small Ruminant Research 59:141-156.
Ruiz F.A., Y. Mena, J.M. Castel, C. Guinamard, N. Bossis, E. Caramelle-Holtz, M. Contu, M. Sitzia and N. Fois. 2009. Dairy goat grazing systems in Mediterranean regions: A comparative analysis in Spain, France and Italy Small Ruminant Research 85:42-49.
Walker J., L. Coffey and T. Faller. 2006. Improving Grazing Lands with Multi-Species Grazing. Pages 50-55 in K. Launchbaugh, J. Walker, H. Glimp and R. Daines, editors. Target Grazing: A natural approach to vegetation management and landscape enhancement. ASI, A. Peischel and D.D. Henry, Jr., Cottrell Printing, Centennial, CO.