by Deborah Jeanne Sergeant
You may think of the trees on your farm as a good source of shade for pastured animals, sap for maple syrup production or perhaps as a long-term timber harvest; however, Steve Gabriel offered many more uses for trees in his presentation “Trees for Livestock Food and Medicine” hosted as a recent webinar by Food Animals Concern Trust (FACT), a national non-profit organization advocating for safe, human production of animal-sourced foods. Larissa McKenna, humane farming program director, emceed the event.
Gabriel owns Wellspring Forest Farm in Mecklenburg, NY and represents the Cornell Small Farms Program.
He said agroforestry used to be considered “farming” and that only in modern times has the need occurred to delineate between the two because of viewing trees as being “in the way” of farming.
“It was really only coined a term in the ’70s,” he said.
His own farm is about 50 acres, partially leased, with revenue streams including mushrooms maple syrup, pastured lamb, duck eggs, elderberry extract, education and agritourism. Staying diverse helps him stay nimble as an operation during difficult times. He noted that currently, agritourism has been down since the outbreak and mushroom sales have increased because of more interest in their antioxidant properties.
“We want to farm in the image of a forest,” he said.
He doesn’t want to leave nutrient depleted, compacted fields, which is what he found about nine years ago when he began farming the land.
In 2016, his farm like many in the area experienced drought. His paddocks wouldn’t regrow as he rotationally grazed. People in the area were looking for other places for hay and silage or considering grain to supplement.
“One of the things we prize about ruminant livestock is the lower feed bill in the summer,” he said.
By using Google Maps, he noted at the edges of his property, he realized that the woody vegetation looked pretty lush and good. Maybe his sheep could take to it, he figured. He fenced them into those area and fed them off the landscape. It was a 40-day experiment with sheep in the hedgerows and found the lambing weights were no different.
“They were comfortable and had no weight loss during the drought,” he said.
He considers trees as beneficial for shade and fodder value now.
“These are wonderful in both the wettest years, like 2017, or wet year, like 2016,” he said. “This is a really important characteristic of these plants.”
He specified that “forage” is nearly anything one could feed to an animal, but he uses it to mean plants on the pasture floor. “Browse” means more of the woody animals and “mast” meaning food fed to animals that’s harvested annually from woods for animals.
Gabriel researched trees as fodder, shade and shelter for his book, looking for species that are adaptable, fast-growing, easy to propagate, and offer many secondary products.
“These aren’t the only thing we’re going to offer our animals,” he noted.
Willow, black locust, poplar and mulberry proved top species to provide these as well as their ability to grow in cool, temperate regions.
Gabriel advises excluding livestock for 3 to 5 years allows the trees to grow and to select self-propagating varieties to control expenses.
He uses the template provided by popular pasture management recommendations, using 75% willow as grasses, 15% black locust as legumes and 10% mulberry as forbs. He said willow is high in biomass and tannins, which can reduce methane emissions and parasites. Willow also helps build good windbreaks.
“Willow is easy to propagate, as you take a cutting ideally when it’s in its dormant season or when the sap is beginning to run, although willow is very tolerant,” Gabriel said.
He said harvesting and propagating local willow works well. The diameter should be between the thickness of the pinkie and thumb and it should be 16 to 18 inches long. About three-quarters of that woody material should be underground.
Black locust — functioning like “tree alfalfa” — is high in protein. He said people love to hate it, but it’s nitrogen fixing and it grows rot resistant wood.
“We want to claim it’s non-native, but the people who brought it here were humans who chose to bring it here,” he said.
Gabriel sees some potential for black locust as a cash crop, as farmers may receive $1 to 3 per linear foot for black locust posts between 8 and 12 feet, $45 to $60 for a 22 foot-plus hop pole and between $2.50 and $4 per milled board. He advises planting about 2 to 3 feet apart and then later thinning them out.
“It’s similar in productivity and nutrition to willow, but with lower tannins and thus higher intake,” Gabriel said. “In vivo work showed that the digestibility of tree fodder declined from late spring to autumn and that this decline was much smaller than the decline in digestibility of grass-based pastures in New Zealand over the same time period.”
Poplar also offers effective and attractive windbreaks. Poplar is high in biomass and also provides balanced nutrition. In addition to high digestibility, Gabriel found that mulberry’s fruit provides minerals helpful for pigs and poultry. The trees grow well in a variety of climates.
Gabriel said that mulberry is the best for “mono-gastrics” like chickens and pigs, as it’s the most digestible.
“Mulberry out of these four species is the hardest to propagate but a very important one to have in a system like this,” Gabriel said.
Of course, most farms already have or want additional species.
“Start with those four and branch out from there with whatever else would be good for shade, fodder and shelter goals,” Gabriel said.
The nutritional value of the fodder trees provides varies at different points in the season. It’s lowest when trees are just leafing out, it peaks after full leaf, and declines during senescence through leaf drop.
“We know that at the top of that peak, you’ll get a good nutrition, perhaps peak nutrition, but that’s not the only thing as far as palatability,” Gabriel said.
The species of tree also makes a difference. Willow peaks much earlier in the season than black locust, for example, and others stay green much later in the year.
Gabriel said the nutrients offered by each tree vary throughout the season. Black locust’s crude protein content declines over the season, as well as its values for potassium. Its level of manganese peaks in early July but also spikes in early September and October.