Tree Fodder Builds Resilience (and Carbon) on the Farm
By Steve Gabriel
Our farm was first captured by the idea of tree fodder out of necessity. In 2016 our region of New York suffered a tremendous drought coupled with record-high temperatures and the pastures simply stopped growing. Our neighbors were draining their ponds and driving two states over to find hay to feed animals. Members of the local Mennonite community, perhaps more versed in traditional ways, saw the writing on the wall and sold off or butchered their animals.
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.
That year, we managed to sustain our flock of sheep on the marginal edges of forest and hedgerow for about 45 days. As we crept into September and some relief finally came from the rains, we knew that our perspective, out of necessity, had forever changed. If we were going to farm livestock, we needed to plan for the worst of times, not base our plans on assumptions that everything would be “normal.” Indeed, since then, it seems like each year the climate pendulum swings from too dry and then too wet. This has a range of effects on pasture production, but the trees always seem to grow reliably.
As we learn more about tree fodder, both in research for writing the Silvopasture book, as well as our ongoing farm experiments and observations, my appreciation for the essential role tree fodder will play in sustaining livestock - and arguably ultimately humans living in cold climates - only increases with time. Let me share some more about what I have learned, and more about where we have to go to see fodder emerge as a significant contribution to a holistic grazing system.
Defining “Tree Fodder”
It’s important to start out by defining what I 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), which I am not.
For instance, we could say the honeysuckle and buckthorn we first “found” on the property is now “given” to the sheep, as over time we’ve managed it as a source of feed.
So, if you peruse the web, you might see the word fodder used for everything from grasses to ag 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, I 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
Tree fodder will by no means replace forages but act at best as a supplemental source of food. Our initial understanding was that tree fodder offered us a resilient food source for animals, especially in extreme conditions when pasture plants are not thriving. This is especially during times of dry or drought conditions, often exacerbated by hot temperatures that suppress the growth of the cool season grasses we rely on (at least in Northern climates).
Even better news is that tree fodders also offer an impressive buffet of nutritional benefits, including many trace minerals and nutrients not abundant in most pastures. 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 offers several positive effects for ruminants, including increased milk production, better growth of fiber, increased lambing percentage, and most notably a reduction in the 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 the unique microclimates of a farm and placing trees in the right place for that stage of ecological succession.
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 feed. Not that we are going to plant or encourage the expansion of these species, but rather we are finding that our sheep are providing a means of cost-effective vegetation control. Rather than eradicate them, we are managing these and other species to restore balance and provide an even more diverse diet to our animals.
And finally, 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 baleage, 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.
Next Steps: Managing quality and quantity
As part of a SARE Farmer grant, our farm spent two seasons collecting leaf fodder samples for six species on our site, three planted (willow, poplar, black locust) and three naturalized (buckthorn, honeysuckle, and wild cherry). Our results indicated that all have different values as feed sources. It confirmed what so much of the research and experience of farmers does; there is value in feeding out tree fodder. The main issue that remains, is when and how to do it, to best maximize the quantity and quality of the materials.
At the core of these questions is the need to better understand the tolerance of a given tree species to grazing and its response and regrowth, to know in other words what is a sufficient rest period between harvest events. We can be pretty assured that trees won’t grow back in the timeframes outlined in rotational grazing methods (30 - 60 days in our climate) which often means we can graze the same patch of ground three or four times a season. Likely, in cool temperate climates, tree fodder harvest is once per season, maybe twice in some circumstances.
We have a lot to learn but can start by getting to know some species and their potential. See our grant report and resources we created from the project, including a series of recordings from a day-long webinar we hosted, at www.SilvopastureBook.com under “Tree Fodder”.
Getting Started: What we know
So, with all these benefits, why aren’t all livestock farms loading up on tree fodder both during the growing season as well as for winter feed? The short answer is; 1) farmers aren’t used to thinking about and valuing trees as a feed source, and 2) we don’t have refined techniques to manage and feed out tree fodders in the same way that we have practiced for pasture forages.
A major point to make here is that the goal is arguably not to ever replace common pasture forage but rather to supplement this feed as a nutrient-dense and climate resilience source of food and medicine for our animals.
While there are many management questions that remain, we have enough information to get started and start to gain more experience with tree fodders while receiving some of the benefits to our livestock almost immediately. To this end, here are some recommendations for approaching tree fodder in your context:
1. Start with known species that have a long track record as fodder
Some examples of this include Willow, Black Locust, Poplar, Mulberry, Ash, and several others species, likely many are around you already on the farm landscape. Our website, wellspringforestfarm.com shares the results from three species we planted onsite and three that we found naturalized to the farm and breaks down their nutrition.
Another great resource is a database from Denmark that provides some feed values as a starting point, through there are likely differences in those values depending on where you are located (more on this below) https://www.voederbomen.nl/nutritionalvalues
2. Look around your site for potential existing fodder sources and ID them
Established vegetation offers a great place to start, as you can take advantage of tree fodders ready to have livestock engage with them. You can also partner tree fodder goals with vegetation management, i.e. thinning and clearing.
Seek out to especially note those “bad” or “invasive” plants that other have told you shouldn’t be there. They ARE there, and they can provide valuable food while being managed in your livestock system.
3. When planting trees for fodder, protect them until browse height is sufficient and bark is hardened
It may not be a coincidence that many of the top tree fodder species are already quite hardy, fast-growing, and respond positively, or at the very least will recover, from animal impact. When establishing new plantings, however, the trees need time to build up theri reserves and be “ready’ for the animals, or else they will be outright destroyed. We have found that some species, like black locust, can be tall enough and have a hard enough bark to resist getting their bark stripped off in as little as 4 - 5 years. Others, like Alders, are still prone to stripping even after 10 years on the farm. Keep these variables in mind when you are planning.
3. Approach the work based in the bodily wisdom of your animals, so fodder is a safe part of their diet
There is a lot of fear around the toxicity of plants in grazing systems, and especially with tree fodders. While there is never NO risk, most often a toxic event happens because:
A) the animal is not used to foraging for their own foods (i.e. is fed rations in confinement) or
(B) the animal is deficient in something and overeats a toxic plant to compensate
Our experience on the farm is that our sheep have eaten many of the plants on the “toxic” lists, but appear to not overindulge but self-regulate their intake to a safe level. We spent so much of our early years on our knees in the pasture, clipping wild cherry sprouts because we read they were toxic on a list. Turns out the sheep love eating them and there is only risk if a certain (rare) sequence of events occurs. We are no longer worried about toxic plants in the landscape, for the most part.
Steve Gabriel is an ecologist, forest farmer, and educator living in the Finger Lakes Region of New York State in the US. Throughout his career, Steve has taught thousands of farmers and land managers about the ways farming and forestry can be combined as Agroforestry Extension Specialist for the Cornell Small Farm Program and by co-stewarding Wellspring Forest Farm, where alongside his family they produce mushrooms, maple syrup, pastured lamb, and nursery trees. Steve co-authored Farming the Woods with Ken Mudge in 2014, and is the author of the new book Silvopasture, released in 2018.
Wellspring’s SARE Farmer Grant; projects.sare.org/sare_project/fne19-930/
Animal Behavior with Dr. Fred Provenza | Hacked by Mr.ToKeiChun69
Tree Hay: A Forgotten Fodder | Agricology, agricology.co.uk/tree-hay-forgotten-fodder.