We decided to take a chance, and looked to the marginal edges of the farm for help. We had heard our Katahdin sheep would make use of woody materials, and noted that while the grasses and legumes looked brown and parched, the shrubs and trees in our forested hedgerows remained quite green. Looking back, we were naive in the details and didn’t know much about feeding woody plants to livestock. I like to imagine our ancestors learned over centuries in the same basic way; observed a factor in the landscape, tried something, and discovered a new way to sustain life.
To further explore the use of tree fodder we sampled tree fodder from six species on our farm; three we planted (willow, black locust, and poplar) and four common established woody species (honeysuckle, wild cherry, and buckthorn) that often get a bad rap in grazing circles. This project,
"Quantifying Nutritional Value and Best Practices for Woody Fodder Management in Ruminant Grazing Systems" collected data in 2019 and 2020.
On Farm Tree Fodder Research
In addition to this data collection and analysis, we completed a literature review and compiled references for tree fodder in an open-source ZOTERO library.
For our research, we chose three species we had established on the farm and three species that are naturalized and common on many farms, often cited as "invasive" or "noxious" but plants we saw the sheep seem to utilize and enjoy over the years.
2021 Tree Fodder Seminar Recordings
In December 2021, we welcomed several leaders in the tree fodder and silvopasture to share in a one-day virtual seminar. The event was hosted by Steve Gabriel of Wellspring Forest Farm in New York and featured the work of a range of researchers and practitioners including Lindsay Whistance (Organic Research Centre, UK), Eliza Greenman (Tree Crops Specialist, HogTree), and Ashley Conway (Center for Agroforestry).
Recordings from this event are available here:
Defining Tree Fodder
It’s important to start out by defining what we mean by tree fodder. If you research the definition for fodder, it couldn’t be more general. Wikipedia notes that fodder is, “any agricultural foodstuff used specifically to feed domesticated livestock, referring in particular to food given to the animals, rather than that which they forage for themselves.” This implies at least some intentionality on the part of the farmer, but it's hard to draw a line between food “given” and food “found” - unless of course you are talking about a confined livestock feeding operation (CAFO).
For instance, we could say the honeysuckle and buckthorn we first “found” on a landscape is now “given” to the sheep, as over time we’ve managed it as a source of feed. If you peruse the web, you might see the word fodder used for everything from grasses to agricultural byproducts (like soy hulls) to tree leaf material. There are also the words “feed” and “forage” and “browse” and “mast” that you might come across. They can be used in a wide range of ways, but for this article I want to define them as:
Forage: The commonly cultivated mix of “pasture” plants including grasses, legumes, and forbs that provide the basis for a grazing system
Browse: The opportunistic harvest of existing “wild” woody shrubs and trees by grazing animals
Mast: Food for livestock (or humans) coming from trees and shrubs as fruit (soft mast) or nuts and seeds (hard mast)
Fodder: Leaf material from trees and shrubs that offers nutritional and medicinal qualities
To eliminate any confusion, we have found it best to simply use the phrase “tree fodder” as the best way to describe intentional systems to cultivate leafy material for grazing animals.
Just keep in mind as you read around that the terms above are used in many different ways. I don’t have any passion to try and reign them into one set of agreed upon words. What is important is that livestock feed can come from many sources in the landscape, and that we all work toward a deeper understanding of the potential.
Benefits of Tree Fodder
All tree fodders offer comparable nutrients to grasses, legumes, and forbs, with a similar variability in specific amounts as with the more common grazing forages. See our grant report above for some examples. Other resources include:
Secondary Compounds (= Medicinal)
Many tree fodders additionally express a number of “secondary compounds” that act as medicinal compounds. Tannins are some of the most promising of these, which have been shown to essentially slow down the digestion of ruminants without compromising their ability to access the food value in foraging.
Research has shown that the moderate consumption of tannins offer several positive effects for ruminants, including increased milk production, better growth of fiber, increased lambing percentage, and most notably a reduction in risk of bloat and various problems associated with internal parasites.
Tree fodder systems can also enhance a range of environmental aspects of a farm, where plantings can act as buffers to capture soil runoff and mitigate the effects of excessive water flowing over the land. Tree plantings can be buffers from the wind and snow, can increase bird and wildlife habitat, and provide shelter and early season food sources for pollinators. These benefits can convey if tree species planted for fodder are well placed after assessing needs for environmental
While our experience with tree food came first from notable species such as willow, poplar, and black locust, we quickly realized that other plants on the farm could also be beneficial. It turns out that many of the so-called “invasive” plants that are often seen as a negative force such as honeysuckle and buckthorn, offer unique nutrients and benefits as a feed. Not that we are going to plant or encourage expansion of these species, but rather we are finding that our sheep are providing a means of cost effective vegetation control. Rather than eradicate, we are managing these and other species to restore balance and provide an even more diverse diet to our animals.
Storing Nutrients for Winter
Not only can tree fodders offer a feed source during the active growing season, but more are finding they are also a potent feed that can be processed and stored for winter. In forage systems, you might be familiar with the production of silage or balage, which is effectively harvesting grasses and legumes and wrapping or packing them in plastic to seal them off from oxygen and to store over winter. This offers some advantages over producing dry hay, which requires the weather to cooperate and for the farmer to get their timing just right. Regardless, farms utilize a combination of strategies to store grass/legume feeds as dry material or ensiled material, and the same can be done with tree leaf material and even some of the woody parts if they are young and supple enough to digest. There are several folks digging into the details of this, with Shana Hanson and 3 Streams Farm in Maine providing a lot of good resources and data on the process.
All these benefits to the farm, and the icing on the cake is that many excellent tree fodder species also excel at carbon capture. Faster growing trees are good for carbon and good for establishment in silvopasture since animals can be integrated with them sooner.
Other resources to check out:
Tree Hay: A Forgotten Fodder
Black Locust: A Tree with Many Uses (Steve Gabriel): https://smallfarms.cornell.edu/2018/01/08/black-locust/
Article on Propagating Mulberry (Akiva Silver):
New Zealand Willow & Poplar Research Trust: http://www.poplarandwillow.org.nz
Pollarding Physiology and Practice: http://www.coppiceagroforestry.com/blog/april-28th-2017
Mo' Mulberry; Propagation Guide