Wisely controlled browsing of Northeast woodlands by goat herds could increase revenue and reduce costs to goat owners, decrease woody plant control costs to woodlot owners and reduce the forest area treated with herbicides. This Cornell and Penn State project was initiated to determine how to enhance meat goat production while using the goats to control woody interfering plants in mature forests. Goats were placed in mature hardwood forests, with a well-developed understory of interfering woody species (i.e., American beech and striped maple).

Goats at Cornell University's Arnot Forest. (Photo courtesy of P.J. Smallidge)

During each of the three years, 100 to 180 goats/year were maintained at the Cornell University's Arnot Teaching and Research Forest for use on the project. Herds of approximately 20 goats were contained within an electronet fence. Paddocks for the project were - acre though collaborators found 1 to 2 acre paddocks more time efficient. Goats were fed a daily supplement of 2-2.5% of body weight and provide fresh water. Fence lines were checked daily to assure integrity and charge and to exclude predators. There were no cases of predator problems during the three years of the project. Goats were moved to a new paddock when the overwhelming majority of green foliage was consumed. In an extremely dense understory, 20 adult goats would stay in a paddock for 3 to 4 days, while 20 juvenile goats would stay for 7 - 9 days.

Goats were assigned randomly to treatment groups. Year 1 included a comparison of 20 vs. 5 goats per group and daily supplement vs. rotational (woods and pasture) with duplicates of all four combinations. Year 2 treatments included normal vs. low protein in feed and normal vs. low fiber in feed, with one replicate group per treatment. Year 3 treatments included total mixed ration vs. home mixed ration (soy-corn dominated) for adults and juveniles on total mixed ration. In all cases the experiment response variables for goats was change in weight and for vegetation was the percent mortality in the sapling and seedling layer.

In addition to using Arnot Forest, on-farm collaborators were solicited through trade publications and especially through extension educators. The project provided all materials and supplies and made 2 - 3 visits per month to inspect animals and evaluate activity. We solicited primarily private owners. Seven locations and collaborative teams worked with the project and represented a range of forest owner objectives from mature forest to suburban "forest-scaping" to vineyard reclamation.

The project demonstrated that goats can be used effectively to control woody understory that has developed in the partial shade of mature hardwood forests. Effectiveness, used here as an integrated result, is defined by the maintenance of goat health, goat weight gains that are comparable to animals feed ad libidum, the mortality of significant numbers (40 - 95% depending on species) of undesirable saplings, and the lack of damage to stems > 4 inches in diameter of commercially valuable species.

We evaluated stocking rates at 5 and 20 goats per - acre paddock. Weight gains and sapling mortality were less at the lower stocking rate than the higher stocking rate. A herd of 20 goats had good effectiveness (weight gains and sapling mortality) and was logistically manageable. Higher stocking rates are possible and upper limits should be dictated by the ability of the herd manager to move goats in a timely fashion to avoid damage to desired tree species.

Goats at Cornell University's Arnot Forest. (Photo courtesy of P.J. Smallidge)

The woody vegetation that develops in the partial shade of a mature, managed forest is usually dominated by species that remain because they are unpalatable to the large deer herds common in eastern forests. Thus, the dominate species are of poor nutritional quality even-though fresh weight biomass is often abundant. The maintenance of good goat health depends on a daily high-quality supplemental feed at approximately 2% of body weight for mature animals and 2.5 - 3% of body weight for animals less than 12 months of age. The supplemental feed can be a simple mixture of corn and soybean components or a total mixed ration.

The mortality of woody understory, expressed as percent of original number of stems, varied considerably by species and by the procedures used to manage the herd. What most forest owners would consider as inadequate (less than 30% mortality of sapling numbers) occurred with low stocking rates of goats (5 per acre paddock) or with a daily supplement of feed having crude protein levels below 12%. The optimal sapling mortality occurs with mature goats receiving a total mixed supplement at 2% of body weight. This combination resulted in 90-100% mortality for striped maple, hemlock, and red maple and 50-90% mortality for hophornbeam and all but the smallest beech. Juvenile goats with a total mixed ration at 2.5% body weight provided the second best control of saplings with mortality levels of 100% for striped maple, 67% for red maple, and 25% for all but the smallest beech. Mature goats fed a simple home ration of corn and soy beans girdled (killed) 67% of hemlock, 57% of striped maple, and 38% of all but the smallest beech. In all treatments stems greater than 4 inches in diameter were not girdled. Also, there was no damage to sugar maple saplings at either the Arnot Forest or the one collaborator who had sugar maple saplings in the paddocks. All seedlings, including sugar maple, are consumed by goats.

The economic analysis for this project is based from the perspective of the cost per acre for a goat producer to provide a service to a woodlot owner. The profit potential for a goat producer would incorporate the cost per acre against the revenue per acre received for services, sale price of the animals, and reduction in costs that would be incurred on-farm. The cost per acre for control of vegetation depends on the number of goats and how they are managed. The cost for a goat producer to transport and manage goats in an off-farm woodlot, and thus the minimum fee that might be charged a landowner, are comparable to herbicide treatment with a range of $100 to $150 per acre depending on the specific treatment the goat producers uses. Forest owners with small parcels (less than 10 acres of treatment per year) or those with a desire or need to minimize the use of herbicides should consider using goats for vegetation control. A best recommendation from an economic perspective isn't strictly possible given the unique situation of each producer. However, the potential for enhanced profit would likely include elements of the following: herds that include a significant proportion of adults; careful measuring of feed to assure animal health without over feeding; and a marketing plan that targeted small woodlot owners or owners who couldn't or wouldn't be able to use herbicides.

Many forest and rural landowners see goats as a preferred option to other cultural treatments such as hand clearing or herbicide applications. The landowner's primary barrier to adoption and use of this technology will be finding a goat producer willing to provide the service. Most goat producers were interested in the project but skeptical of the financial details. They should be cautious about over commitments if providing business services to woodlot owners, but will be able to use information this project developed regarding the management/production system. Those producers/owners who provide vegetation management service to woodlot owners will especially want to study the details of their system relative to the assumptions set forth in the economic analysis.

The tendency of goats to not damage sugar maple suggests the strong potential for goats to be used in controlling brush in sugar bushes. Goat producers with inadequate land and adequate time to manage off-site herds, or goat producers with mature herds and who seek added income, are the most likely prospects for providing goat control of vegetation. Goat producers can use goats in their own woods, without damaging the long-term health and sustainability of the forest by providing a daily supplement if forage quality is poor and with regular movements of the herd to portions of the forest with adequate forage.

Goats at Cornell University's Arnot Forest. (Photo courtesy of P.J. Smallidge)

The prospect for goats as a profitable vegetation management tool is favorable under certain conditions. Goats can be viewed as one of several tools that a woodlot owner might select to control undesired vegetation. Of special comparison is the potential role that goats play relative to herbicide applications. Commercial scale herbicide applications, for a relative context to the projections below, cost woodlot owners between $115 to $150 per acre on lots that are approximately 30 acres and larger. The actual charge to landowners will vary depending on many factors. Correctly applied herbicides can control better than 95% of the target vegetation. Relative to herbicides, goats have a less effective kill, greater logistical challenges, and slower application of treatment for large parcels. However, large parcels are a small subset of rural ownerships. Goats will find their greatest profit potential with audiences: (i) who have parcels less than 75 acres and thus too small for a favorable economy of scale with herbicides or (ii) from woodlot owners, like maple producers or suburban owners, who wish to avoid herbicides for business or personal reasons.

By Peter J. Smallidge, pjs23 [at] cornell.edu

Peter Smallidge is with Cornell University's Department of Natural Resources. He is the State Extension Forester responsible for forest management and stewardship, and is Director of the Department's Arnot Teaching and Research Forest. This piece is extracted from a larger project report.