Efficient Leaf-dense Tree/Shrub Silage Production from Field Edges: Climate-resilient Winter Forage Supplement for Cattle, Sheep, and Goats

Progress report for FNE22-013

Project Type: Farmer
Funds awarded in 2022: $30,000.00
Projected End Date: 12/31/2024
Grant Recipient: 3 Streams Farm
Region: Northeast
State: Maine
Project Leader:
Shana Hanson
3 Streams Farm
Karl Hallen
State University of New York (SUNY), College of Environmental Sc
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Project Information

Project Objectives:

*See January 15, 2023 Progress Report                               under Materials and Methods below.


Project Objectives:

This project seeks to complete/perfect machinery and test methods for efficient field-edge production of improved nutrient-dense broadleaf tree/shrub silage, analyse nutrition, trial how much cattle, sheep and goats will eat as climate-resilient winter supplement, and assess utility/feasibility in comparison to conventional forages.  

We will: 

1.  Complete/perfect Karl’s chain-flail leaf-separator.  


    • Costs of new/used components, labor;
    • Leaf/woodchip proportion plus textural photo per species/age/diameter/length feedstock; 
    • Machine, final diagram, photos, video.  

2.  Obtain Laboratory Results.  

    • Assess safety of fresh-stripped or ensiled:  cherry, maple, box elder;  
    • Examine leaf-silage nutrition alongside animal intake; 
    • Examine changes, fresh to ensiled. 

3.  Harvest broadleaf silage from  3 field-edge sites with 5- to 20-year growth of 8+ broadleaf tree/shrub species using power tools and leaf-separator.

  • Collect/pack/seal/label leaf-silage in barrels.  
  • Summarize:  species stem-tallies, labor-times, costs, leaf-silage yields. 

4.  Offer/don’t offer cattle, sheep and goats unlimited weighed amounts of leaf-silage before usual rations for repeated trial-periods, plus two short trials.  


    • How much they eat. 
    • Change in amount of grass-hay they eat.  
    • Effect on cow and goat milk quantity.

5.  Compare to other available forages:   

    • Labor & costs per animal utilization, per nutrition, and per yield. 
    • Farmer-participant observations.     

Climate irregularities are escalating, making Northeastern forage harvests unreliable.  In 2020, after low 1st crop hay yield, many Maine farmers grazed 2nd hay-crop to make up for pasture deficits.  Storage shortfalls were met with 25% pricier hay from distant places.  Financial margins of most Northeastern farms are too tight for such purchases. 


Organic Pasture Rule variances in 2018 and 2020  allowed Organic farmers to use stored forages when pastures failed.  COVID 19 triggered an increase in homestead livestock acquisition, further impacting winter forage supply (Bayly 2020).


Trees and shrubs have deep roots and are more drought- and flood-resilient than grassland.


Woody field-edges of Northeastern farms hold disproportional biodiverity, correlating with carbon sequestration and supporting pollinators plus other threatened lifeforms.  These edges add “rough” landscape texture and more transpirational moisture than flat fields, doubly contributing to “small” rain-cycles which support plant/tree/soil-health essential to climate stabilization (KravčÍk et al. 2007). 


Withdrawal of milk-processor Horizon from the Northeast highlights economic advantage of large consolidated Western producers, whose hedgerows and biodiversity are long gone.  Energy-intensive deep wells replace small rain cycles.  Meanwhile, sheep and goat dairies are increasing, in Vermont especially.  Northeastern producers can create a market edge based upon ecological sustainability and livestock health.  All ruminants perform better with access to browse (Provenza 2020); our field-edge silages extend such benefits into winter.  


Deforestation and soil losses from agriculture factor heavily in the climate crisis (Jia et al. 2019).  The archeological sign of tree-based ruminant agriculture is no soil erosion (Marinova et al. 2007, Gardner 2002). 


Since SARE FNE18-897, three (of six) participating farms have responded to droughts with increased use of broadleaf forages.  We now want the labor-effectiveness of chipped leaf-silage (Austad 2003; Hanson 2020a), but with reduced wood-content, as woodchips even from 1” diameter brush decreased feed  value by about 40% (Hanson 2020b). 


Two of these farms’ livestock are solely grass- and browse-fed.  100 Northeastern grass-fed beef producers are similarly forage-dependent, and especially need a climate-reliable forage supplement.  300 Northeastern sheep farms and 10,000 Northeastern (cow-) dairy farms, plus smaller numbers of goat farms, can also benefit. 


Efficient hay-balers took 50 years to develop from the original stationary invention; 30 years of industrial biomass equipment evolution give us a running start, to increase efficiency and quality of broadleaf silages.  Climate pressures incentivize us to minimize harvest-labor and improve leaf-content of these aromatic, fresh-textured, and easily-stored silages. 


Karl Hallen, SUNY Willow Biomass Project and Hallen Farm, will begin work on his second chain-flail leaf-separator this winter (pre-grant period), for us!  His first preceeded a chipper for successful production of “clean” leaf-free wood pellets.   Inspired by huge chain-flail de-limbers used in paper-pulp harvest, these machines have short chains attached to two safely-housed rotating cylinders.  Our leaf-separator’s post-flail feed-rollers can send stripped branches directly into a chipper for livestock bedding material, a product already used on Northeastern farms. 


Such mechanized leaf-silage processing can be scaled up for large farms, transforming nuisance field-edge maintenance.


We propose to regeneratively harvest 1- to 20-year broadleaf (mostly tree plus some shrub) growth from ground-level with power tools, from stone-wall field-edges of three sites, plus harvest micro-sites of additional tree-species.  We will test and perfect the chain-flail leaf-separator, then produce sufficient  leaf-silage to run three 4-week trial-cycles per farm at two farms, with/without leaf-silage (same-group control) for Freisan-Dorset sheep, Saanen goats and Jersey cattle,  plus short trials for Angus and Holstein cattle.  We will determine how much leaf-silage these ruminants consume in winter, which broadleaf species-mixes were best received, nutritional value of what they ate, how much conventional forage is saved,  milk quantity changes, and bedding-chip yields from stripped brush.  


Farmers and researchers need to know whether harvest labor-time and costs can be worthwhile for yields that the leaf-separator provides, whether animals will accept significant portions of this forage-product, whether milk-yield will be impacted, and what nutritional needs are met.   Our answers may support:


  • Juan Alvez, UVM, collaborating with UNH to test addition of leaf-silage into TNF, with GHG emissions, animal health/performance, and milk shelf-life targets;
  • Fitting the leaf-separator plus feed/collection systems to roadside leaf-silage production trials with our contacts at Lucas Tree Experts;
  • Karl Hallen trial-separating and -feeding plantation-willow silage from SUNY Willow Biomass Project;
  • 3 Streams Farm re-harvesting 6-year growth of the SARE FNE18-897 Demo Plot in 2024-25; the leaf-separator will streamline measurement of yield edible-portion for any such research.  


Our Farmer Project can support scale-diverse Northeastern leaf-silage harvests, plus agricultural/wood-industry collaborations, to strengthen Northeastern ruminant feed-security ecologically and sustainably,  and meet climate challenges. 


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Materials and methods:

January 15, 2023 Progress Report

* Also look below for Methods and Materials as proposed.

A) Flail rotor with half-barrel housing
A) Flail rotor with half-barrel housing.
B) Flail rotors in front of exit tire rollers, wavy gathering belt above
B) Flail rotors in front of exit tire rollers, wavy gathering belt above.
C) Wavy gathering belts over tire rollers, two feed systems
C) Wavy gathering belts over tire rollers, two feed systems.
Day 1 - Karl fixed a messy hydraulic leak, on the first day of use at Y Knot Farm.
Day 1 - Karl fixed a messy hydraulic leak, on the first day of use at Y Knot Farm.
Day 2 - Shana and Susan ran the leaf-separator for the first barrel of gray birch (Karl Hallen pic)
Day 2 - Shana and Susan ran the leaf-separator for the first barrel of gray birch (Karl Hallen pic).












Much-awaited arrival of the Leaf-Separator Machine: The Leaf-separator arrived in Maine on September 29th, 2022, just in time to fill 4 barrels with green tree leaves at Susan Littlefield’s Y Knot Farm (Belmont, ME) before hard frost, and learn what quirks of the machine we can address over the winter. We originally planned to have the machine in May, for extensive harvesting this past summer and livestock trials this winter, but machine creator Karl Hallen (SUNY EFS Tully Research Station, and Hallen Farm, DeRuyter, NY) broke two ribs in a mishap on a different machine in late winter, which postponed the heavy work of machine fabrication, and complicated his workload as a whole (note: Karl tack-welded, tried, then changed 3 major redesigns of our machine; also, multiple engines, pumps and motors were installed then changed out, before arriving at the current configuration). Our grant period accommodates the necessary shift of our harvests and trials to 2023-’24.

Day 2 - Susan caught, Shana fed gray birch. The main catchment barrel is directly under; the barrel in front catches some leaves that miss.
Day 2 - Susan caught, Shana fed gray birch. The main catchment barrel is directly under; the barrel in front catches some leaves that miss.
Day 3 - Black cherry leaves machine-separated directly into the barrel
Day 3 - Black cherry leaves machine-separated directly into the barrel.
Day 3 - Seamus Blake, interested goat keeper from Virginia
Day 3 - Seamus Blake, interested goat keeper from Virginia, helped limb brush and run the leaf-separator machine.
Day 3 - Shana packed down and topped off the first full barrel of black cherry leaves (Seamos Blake pic).
Day 3 - Shana packed down and topped off the first full barrel of black cherry leaves (Seamus Blake pic).

With brush cut, limbed and piled first, we can pack a 30 gallon barrel (about 100 lbs.) of quite intact leaves (also some small twigs, depending upon species) in less than an hour. One multi-trunked black cherry tree on the Y Knot Farm stone wall, coppiced by Susan 10 to 15 years ago and then all 3 trunks pollarded in a 25 ft. high branchy form (too high for Susan) by me Shana 4 to 5 years ago, I now lopped much lower with 9 foot pole chainsaw after climbing to de-limb. This one tree provided about 115 lbs. of leaves – 35 gallons when tightly packed.

We’ve identified many improvements (mostly for the next prototype and beyond our current Farmer Grant budget) to speed up machine leaf separation in future (see “Labor efficiency” below). For this time around, we are excited that IT WORKS!


Machine details: The 18 flails (9 attached in spiral pattern to each of two vertical rotating square axles) are each 5 or 6 links (5 on lowest ones so they don’t hit the frame) of 3/8” high-tensile steel chain, large, heavy and durable, such as used to tie a bulldozer to a trailer. Karl Hallen wanted the chains one to two links longer, to get 95 to 100% of the leaves without speeding up the flails nor slowing the feed speed down. A wavy interlocking gathering belt assembly for a corn head on a John Deer forage harvester drags short or floppy branches through the chains from above. The wavy belts came in a set length; Karl regrets that he sized the frame to match that length, thereby limiting room for chain flails to spin, and limiting our flail chains to their current length.

The main feed system consists of ingoing and outgoing pairs of rollers made by stacking small tires vertically onto four rods per roller, leaving the unmounted tires very squishy to grab diversely shaped and sized branch butts. It works great on long, stiff stems and branches; “User-friendly!” I exclaimed in relief after a summer of suspense. But we appreciate the additional wavy gathering belts. We especially use them when de-leafing gray birch, as those branches are too flexible to get past chain flails to exit rollers without the extra guidance from above. The chain flails tend to send very flexible branch butts to the left (when facing to feed), probably due to spring-loaded floating action of the right half of the machine, which helps the machine as a whole adjust to varying sizes and shapes of branches, but slightly misaligns the two flail rotors. When branches veer off from center, they tangle around the flail rotors, adding labor time to unwind or clip them out. The gathering belts guide branch butts straight through flails, avoiding tangles.

We also used the gathering belt feed for oak from some large Montville, ME pollards; oak branches are very stiff but quite angular, and pieces from pollards tend to be shorter and leafier.

The front and rear tire rollers control stiff long branches or stems well; the gathering belts on top loosely hold and move branches but are situated too far apart to grab branches of small diameter. The gathering belts currently turn on the same axles as the tire rollers, so cannot be moved closer together short of re-design (see below, under “Labor efficiency: Points for improvement”).

We had to slow the gathering belt feed speed (with flow control valve) for the well-attached leaves on oak, since we were already running current flail motors at their top speed (maximum flow valve setting). Though this adjustment increased labor time, slowing the feed speed did provide an excellent (near-100%) oak leaf removal result.

Flow valves; feed roole and wavy belt speed adjustable on left, flail speed aat maximum on right.
Flow valves; feed roller and wavy belt speed adjustable on left, flail speed at maximum on right.

Obtaining specific desired machine parts has been a challenge throughout; Karl Hallen composed each current hydraulic flail motor from two motors, as the correct shank size was available only on even slower motors. The fastest motors of the same product line had been “out of stock;” Karl discovered on 12/7/22 that they had become available, so (after budget consultation) bought and sent them (from DeRuyter, NY) with fittings for Pat Scribner at Doak’s Machine (Belfast, ME) to install (also adding case drains, for increased pressure of faster speed).

These new flail motors offer an rpm gain of 25 to 30% (1,500 rpms continuous, at 14.5 gal./min., versus previous 1,140 rpms continuous at 15.5 gal./min.). This change may or may not achieve desired ranges for both feed and flail speed, as every change affects the hydraulic system as a whole.

This winter Pat will also change out the many imported hydraulic hose elbows - which have faulty threads and were the source of messy hydraulic leaks upon the machine’s arrival - to fittings made to higher specs in USA (and sent by Karl this fall).


Labor efficiency – Points for improvement: Our labor time is doubled by the need to have a second person maneuver outgoing stripped branches. As mentioned above, the wavy gathering belts are too short and/or too far from each other; they barely grip, then drop branches too soon, causing branches to tangle with flails. They thus almost-but-not-quite deliver branch butts to the outgoing pair of tire rollers, which can take branches fully away. The most doable re-design might be to fabricate new larger gears on free-wheeling bearings just on the non-driving (right hand) side, to close the gap, IF gears with a tooth or two more will have a diameter that closes the branch-holding gap just right. Karl thinks that if the belt’s grip on branches is tighter, we may not need more belt length except that required to reach around the enlarged gears. I will explore gear measurements when the heavy tarp comes off for Pat’s work switching fittings and motors, described above.

If the gear math for that simpler fix doesn’t work, an improved machine model would have to have the wavy gathering belt assembly mounted and driven independently of the tire rollers, with tighter spring-tensioned gap between the belts, and/or larger machine frame to support a longer gathering belt assembly, to carry branches successfully to the tire rollers and/or out of the machine completely. Such changes may require an engine (and possibly pump) upgrade to drive the increased number of motors (all not happening on this first prototype).

If gear math for the simpler fix does work, cost of gear fabrication and extra wavy belt links may still be prohibitive for this first Farmer Grant model. If we continue to get branch butts from end of wavy belts to tire roller-grab with a second person’s helping hands, we will discuss potential as well as actual labor-time in our Final Report.

The second human also catches and stacks long outgoing stripped branches, which otherwise hit the ground and bounce back in to tangle. A large reliable chipper-shredder properly positioned to receive would solve this issue, but unless we find additional funds or loan of equipment, we are limited to using our neighbor Jim Rhodes’ small free-standing chipper-shredder as a separate operation.

As mentioned above, the faster hydraulic motors which Karl wanted to drive the flail rotors just became available and are now in Pat’s hands; we were maxed out at top speed on the flow control valve for the flails with current motors. With new motors, we hope* to be able to adjust speed ideally for each leafy feedstock and feed branches through more quickly. (*note: as mentioned above, the motor change may or may not achieve desired ranges for both feed and flail speed, and comes with risk of needing to reinstall the current motors. In June we will find out, using newly mature spring leaves.)


Leaf % of brush, and leaf/woodchip proportion: We just this week measured leaf percentages of red maple, black cherry, gray birch, and red oak brush (4 of the 17 species we have committed to measure); we’d saved bare branches this fall when we packed 5 gallons of leaves of each species. Late arrival of the leaf separator machine, chipper/shredder water in gas and failure to start, and the intensity of fall leaf spreading on our blueberry field, all contributed to our late follow-through. We hope that branch moisture and weight lost by the delay is roughly equivalent to precipitation saturation added by recent storms.

After harvesting from live trunks, the branches were limbed and/or sorted on the ground with criteria of “pieces bearing leaves; long, stiff and straight is good.” Butts varied from about ½” to 2 ½” diameter, and lengths varied from about 2 ½’ to 8’. Upon consideration of the brush itself and our results so far, it seems that percentages of leaves in leafy brush are going to vary by growth history and traits of individual trees, as much or more than by species.

The separator can handle butts up to 4” or more, so long as side branches can gather together at intake; our butt diameters were less as these first loads were side branches and top growth from tall trees of 5 1/2 to 16" dbh, all previously coppiced and/or pollarded (but bringing down shorter this time; some firewood was produced). Next summer we will feed some stems of larger diameter, as there are younger coppiced saplings that we will cut at ground level in other parts of the Y Knot field edges and at MOFGA.

Despite such variability of tree/shrub traits, our data set once complete will give farmers a practical sense of leaf yield per weight of brush, and per volume of woodchip production.

We pointed the small free-standing chipper into a calf hutch on a tarp, then collected chips. We measured weight with a 70 lb. platform scale with round dial, and volume with gallon lines on a 5 gallon bucket. *I regretably neglected to review “Methods” in time; mean branch butt diameters and lengths are eyeball estimates.

Below are figures to date:

Table of leaf % from leafy branches
Preliminary table of leaf percentages of leafy branches from 4 trees, with approximate measurements of branches and trees.

Maple had the lightest wood, and leaf percentages by weight and volume were similar (chips blew notably farther). This particular maple had large young upright growth with leaves almost directly attached – hardly any leafy twigs, so lots of wood per leaves (it took a large armload of branches to produce 5 gallons of leaves). Oak had the heaviest wood, and leaf percentage by volume was much greater than by weight – a 5x8’ trailer load yielded almost two 30 gallon barrels of leaves in 1 ½ hrs., (more leaves per branch made up in time for the slowed feed speed to remove these tightly attached leaves). Just 8 small oak branches produced our targeted 5 gallons of leaves. This oak is a large and vibrantly leafy pollard, and oaks have high carbohydrate storage ability for re-sprouting (Furze et al/. 2019). The gray birch was our least attractive tree with limited new growth, and yet branches yielded higher leaf percentages than one would expect, probably due to having small short branches containing less wood.

Means from this small preliminary data set indicate a yield of 810 lbs. Leaves per ton of leafy branches, and about 8 yards of leaves for every 9 yards of bedding chips produced.


Eating: Susan Littlefield's sheep at her Y Knot Farm (Belmont, ME) enjoyed the 5 -15% of missed leaves remaining on brush from our first speed-adjusting trials of black cherry, red maple and gray birch, all from the first short stretch of Y Knot Farm’s west-side field edge. The sheep also enjoyed a treat of the branches that were too small in diameter or too short for our machine to effectively process (5 to 8% of each brush pile was thus set aside for them). We look forward to feeding them the first few barrels of machine separated leaves once we have more from our harvest this coming summer (see below).


Livestock trial changes: As machine arrival was too late to harvest enough for livestock trials this winter, we are saving the initial 4 barrels (of black cherry, gray birch and red oak) to feed in the long trial with Susan’s sheep, along with next spring and summer’s harvest of the majority of field edges at Y Knot Farm.

Our planned trials aim to measure how much the animals freely choose to eat of our leaf-separated silages, and additionally measure effect on milk yields and on hay consumption. We are considering a shift of plan to replace cancellation of winter cow milking trial with summer 2023 sheep milking trial, due to death of the 3 Streams Farm cow Tulip on 7/21/22, and Y Knot Farm acquisition of 10 additional milking sheep. This trial shift would be contingent upon prompt early summer harvest of the Y knot field edges (possibly reducing desired sprouting and regrowth), and short silage storage period before feeding, as sheep provide milk seasonally and dry up in early fall. Alternatively we will stick with the initial plan of shifting Y Knot Farm’s sheep trial to winter 2023-’24, and see how much hay is saved.

By time of livestock trials next winter, we expect 3 Streams Farm goat group to also be larger, with 8 milking does versus the group of 6 originally proposed. So both long trials may become somewhat shorter depending upon quantity of leaf silage we are able to harvest and pack for these more-numerous-than-planned animal groups, and their appetite for the same. Skyrocketing price of plastic barrels limited us to 64 of them. We will complete trials consecutively versus simultaneously; if not enough silage for all, we will shift our end date from November 30, 2024 to February 30, 2025, re-fill the barrels in summer 2024, and bump some trials to that next and last winter of 2024 -’25 (then update our Final Report really fast at the end!)

Our leaf silage changes with time, becoming more acidic, yet doesn’t spoil if sealed tightly. In past, our animals have eagerly eaten various samples of leaf silages kept over into a second winter. We will already be adding report of sheep intake of older versus fresher silages, due to packing the first few barrels this October. We will report similarly if it becomes necessary to carry over some barrels then harvest additional barrels freshly in summer 2024, for trials in that last winter.

We continue to talk to other farmers who milk a cow, to locate someone who is willing to help fulfill our original commitment to a cow milking trial, despite our worries about producing enough leaf silage for multiple trials. Information about effect on cow milk yield is requisite for farmers to consider any dietary change for their cattle in milk; a one-cow trial falls short of rigorous research, yet at least will give some guidance and hopefully encourage more study.


Harvest area changes: MOFGA Certification Services (MCS) decided in spring 2023 that they will not certify the MOFGA field edges which we will be harvesting. Soon after, they revoked certification of all my livestock, to remove inspector and MCS mistakes documented in the livestock file (the National Organic Program is putting increased pressure on certifiers regarding new and existing livestock rules). So my livestock can use the MOFGA edges, but Glendon Mehuren’s cattle at Faithful Venture Farm (Searsmont, ME) cannot. Initially we thought to solve this by certifying the Y Knot farm field edges for Glendon, then feed non-certified Y Knot sheep from the MOFGA edges. But to avoid insurmountable complexity of certification of such transfer of goods, Glendon decided he and I will choose new field edges to use on-site at Faithful Venture Farm.

New Beat Farm’s (Knox, ME) field next to our planned harvest edge full of green ash has been found to be PFAS contaminated. Since my 3 Streams Farm milk is now clearing from PFAS contamination of unknown source (and unknown level – the tests are of unknown accuracy on goats’ milk), and the State of Maine is enforcing (mostly against those who voluntarily test) a PFAS threshold for sale of milk, none of our farms are likely to use leaf silage from New Beat (despite that New Beat’s field remains certified organic), unless a $400 test finds the tree leaves okay in a logistically doable time-frame (fodder test results last spring took 8 weeks to arrive, and now the lab is even busier).

I put out calls to MOFGA grounds personnel asking for info on the PFAS testing there; it seems the fields by our harvest edges were not tested. PFAS testing at my 3 Streams Farm included 2021 willow silage from MOFGA grounds, which had a different PFAS (PFPEA) that that in my milk (PFOS). This could be from the excess fair newspapers baled and stacked on the roots of the willows (which can be removed), or from my used barrel’s previous contents, or from the soil. The willows there are highly productive, aromatic, and numerous; it is a hard call to remove them from our harvest list.


Samples & Testing: We froze 3 fresh samples each of Y Knot Farm black cherry, red maple and gray birch in 1 quart bags, plus ensiled one 5 gallon bucket of each from which to draw matching silage samples. We plan to send fresh-frozen and ensiled samples for nutritional testing 10 days before starting each livestock trial. We will send maple for gallic aid testing sooner (sending farther - to California Animal Health & Food Safety (CAHFS) Laboratory).

Remaining silage from the buckets will be fed just before livestock trials begin, to rate palatability and use ratings to decide the order in which barrels will be used in the trials.

Our sample of freshly separated cherry leaves packed on 9/29/22 tested at 123.8 ppm of hydrogen cyanide (HCN), well below the 500 ppm toxicity threshold. We will draw from the bucket and send a matching sample of ensiled cherry for same HCN testing, at time of sending other ensiled samples for nutritional testing. [Wilted cherry is known to be dangerous; our one hour-long feed periods will avoid this issue. An additional safety factor is that both Susan’s sheep and my own goats have history and experience of refusing cherry once wilted.]

This Farmer Grant covers nutritional testing of single samples versus three samples (as required for academically publishable replicability) of each type of feed; I have reached out to the UVM Mini-Grant program with as yet no response, and plan to also talk again to André Brito at the Fairchild Dairy Teaching and Research Center (New Hampshire Agricultural Experiment Station, Thompson School of Applied Science) when I provide some promised 2021 leaf silage and seaweed silage samples to him, to explore funding of more stringent triple-testing, plus my wish for additional hydrogen cyanide tests on the cherry silage at different stages.


FundsThe US dollar is depreciating fast enough, or plastic sky-rocketing in value, such that the price of our sealable lever-top barrels doubled in the time between writing the proposal and receiving the grant award. We bought 64 of them - more of them than planned, as we were unable to locate similar used barrels, which became less available related to the COVID 19 pandemic. I (Shana Hanson, Project Leader) moved all except $300 of money allocated to pay myself, to cover this change of cost. Since that purchase, the price continues to rise. We are not sure if 64 barrels is enough; if we fill these and still have time and field edges to continue harvesting, we may use contractor bags tied tightly to seal, inside other less expensive used barrels – IF we decide that the non-food-grade black plastic of contractor bags is no worse in contaminants than the high-density polypropylene #2 food-grade barrels (see below).


Toxins in Packaging: PFAS contamination in our 3 Streams Farm milk became evident last spring, and led to misgivings about using the barrels at all. Our older barrels had been previously filled with a substance used in tanning leather; modern tanning sometimes uses PFAS, in addition to toxic chromium. Clam fluids we had in these older barrels (we use clam shells for soil amendment) tested PFAS-free. Then we found out that NEW food-grade plastic barrels can leach PFAS into foods, as some are fluorinated to decrease permeability. Thankfully, Eagle Manufacturing has told me (after no response for a month) that our new barrels had no fluorination process.

High-density polypropylene #2 plastic barrels can also leach toxic nonylphenol (NP) into water or milk, particularly if stored in sunlight (Loyo-Rosales et al., 2004). Before hearing back about fluorination, and upon reading about the additional concern of NP, I impulsively spent about $300 (possibly reimbursable in exchange for relinquishing last remains of my originally budgeted grant day-stipends) on organic cotton fabric, to sew liners for the barrels. Before sewing, I hope to find out whether nonylphenol becomes gaseous, or whether the cloth will effectively separate our leaf silages from contamination, to keep toxins away from our livestock, and thereby out of our milk (and meat). I await a call back from a person to whom I was referred by an author of the above-cited study.

I haven’t yet searched references about toxicity of contractor bags (which we may use, as mentioned above under “Funds”), but will do so this winter. It may be just as well that we are starting the major harvest a year later than planned.

In past, farmers used wooden silos, or pits in the ground, perhaps covered with an oil-cloth tarp. Modern plastic tarps shed microplastic and possibly PFAS. Dirt adds danger of listeria for sheep and goats, and modern cement has many additives. Bricks may have less additives than cement. Rolled rubber roofing material makes a long-lasting cover, but like contractor bags is not food-grade, and has yet to be reference-searched (by me) about leachates. We will stick with our convenient new barrels for this study (with or without cloth liners), despite misgivings about the plastic.



Furze, Morgan E., Brett A. Huggett, Donald M. Aubrecht, Claire D. Stolz, Mariah S. Carbone, & Andrew D. Richardson (2019).  Whole-tree nonstructural carbohydrate storage and seasonal dynamics in five temperate species. New Phytologist (2019) 221: 1466–1477. doi: 10.1111/nph.15462

Lovo-Rosales, Jorge E., Georgina C. Rosales-Rivera, Anika M. Lynch, Clifford P. Rice & Alba Torrents (2004). Migration of nonylphenol from plastic containers to water and a milk surrogate.  J Agric Food Chem. 2004 Apr 7; 52(7): 2016-20. doi: 10.1021/jf0345696.


Methods and Materials as proposed

1.  Complete/perfect Chain-flail Leaf-separator:  

a.  Complete fabrication.  

        • Report costs:  List potential farmer costs for used and new components, including those assembled pro-bono by Karl, winter 2021-22, plus labor/machining costs.

b.  Test and perfect machine on leafy tree-matter.  Adjust, repair, improve; re-try.  Perfect  design for optimal safety, leaf volume and piece-size, catchment, and work flow. 

      • Provide final machine diagram, photos, video in action.     

c.  Describe leaf-product results:  Collect bundle/species present at harvest sites, plus harvest micro-sites of 7 additional species (black locust, red oak, Norway maple, elm, box elder, willow and multi-flora rose). 

        • Report % leaf-silage from 1 or more samples per 13 tree- species: Collect and weigh about 5 gallons separated leaf-matter/sample type (record:  species, site, approximate mean DBH, mean height of cut, approximate mean butt diameter and length); chip corresponding stripped branches; weigh woodchips.  Divide leaf volume and weight by leaf plus woodchip total volume and weight.   
        • Photograph 17 species of leaf-product with intact leaf, to show piece-size/texture.
        • Freeze 3 leaf-separated samples/each of 17 species (for future study; seeking additional funding).    

2.  Obtain laboratory results:  

a.  Screen wilt-issue species for toxins:  Collect 6½  gallons separated leaf-matter each: black cherry, red maple, box elder.  Draw 3 fresh ½ gal. samples/ species; re-pack/seal buckets; store outdoors in shade.  Test 1 fresh sample each (others for future study), cherry for ppm Hydrogen-Cyanide, maple and box elder for ppm gallic acid. 

***If toxicity found, red-tag separate-harvest zones where applicable.  

In January draw 3 corresponding ensiled ½ gal. samples/species; send 1/species for same testing.  

  • Discuss safety/species including fresh/ensiled differences.

b.  Test nutrition of fresh leaf-matter and stored leaf-silage from each 100-800 ft. species-mix-distinct stretch harvested:  

Hang ribbons at 100 ft. intervals; change color per species-distinct stretch.  At beginning and end of each color-stretch, and at each intermediate ribbon, fill 5-gallon bucket; seal.  Mix bucket-contents per species-distinct color-stretch; freeze 3x1 qt. fresh samples.  Re-pack/seal 2 buckets/species-distinct stretch; label with corresponding barrel-numbers.  Store outdoors in shade.  In January freeze corresponding 3x1 qt. ensiled samples/bucket.  Send 1 fresh and 1 ensiled sample/bucket, to DairyOne (seek outside funding for additional lab-tests to replicate results). 

From each barrel fed (see 4.c. and d. below), pack/seal 3 qt. bags from different parts of barrel, then mix/re-pack/seal/label/freeze the 3 bags.  Send samples for remaining funded tests, choosing variety re: animal response (seek outside funding to test more barrels and to replicate results).  

  • Report:  MC, DM, CP, SP, ADF, NDF, NFC, TDN, NEL, NEM, NEG, RFV for all samples; plus 10 minerals for 10 samples; plus Water-Soluble Carbohydrates, Rumen-Degradable Protein and pH for 3 fresh/ensiled pairs of samples, and Ammonia in 3 ensiled samples of the pairs; yeasts and mold counts if needed.
  • Examine/report on pH and WSC changes from fresh to various time-spans ensiling;
  • Relate nutritional results to animal intake/barrel and nutritional requirements. 

3.  Harvest 3½ to 4 tons (60-70 barrels) broadleaf silage from field-edges, using power tools and leaf-separator:  

a.  Thin trees to 10’ minimum spacing, remove growth encroaching into field, and top-harvest (pollard) remaining stems, of 5-20 yr. growth:

~  300 lineal ft. + 2,000 lineal ft. at Y Knot Farm., Belmont, ME;

~  800 lineal ft. at New Beat Farm, Knox, ME; 

~  Up to 2,600 lineal ft. at MOFGA’s Common Ground, Unity,ME,


using:  Riobe One Plus 18 V Lithium Cordless and Stihl HT56 CE 9 ft. 2-cycle 9-ft. pole-saws; Stihl MS170 chainsaws.   

b.  Feed harvest through chain-flail leaf-separator (above, on wheels) into barrrels placed beneath; tally species stem-counts per numbered barrel; seal, transport, store in shade.  

        • Report per site:  labor-time,costs/leaf-silage yield; summarized species %s from per-barrel stem-tallies; growth-age description. 

4.  Livestock Trials:

a.  Rate buckets/species-distinct harvest stretch for Palatability to 3 Long-Trial ruminant groups (see c.  below).  Offer 1 qt./head/species-distinct stretch; Knot sheep use Y Knot leaf-silage; 3 Streams cattle and goats use MOFGA and New Beat leaf-silage.  Observational ratings consistent with SARE FNE18-897:  

0 = refused =100% left;

1 = tasted = 80-95% left; 

2 = eventually consumed = 95% gone within 1 hr.;

3 = immediately consumed = 95% gone within 10 minutes;  

In-between ratings at .25 increments. 

b.  Assign barrels: List composite buckets by palatability rating (use mean across 2 groups at 3 Streams Farm), highest to lowest.  Start with barrel numbers from harvest areas corresponding to buckets in order listed, and assign barrels consecutively, re-ordering all 

Y Knot barrels for Y Knot sheep, and 

MOFGA and New Beat barrels as follows:  3 barrels to 3 Streams Farm then 1 to Faithful Venture Holsteins or Meadowsweet Angus cattle, alternating assignment.  Repeat and list barrel label-numbers/farm until all are assigned (joint use of barrels for 3 Streams cattle/goats.)

Transport assigned barrels to livestock trial sites.  

c.  Long Trials:  

~  Y Knot Farm Friesan-Dorset dairy ewes (12);

~  3 Streams Farm Saanen dairy goat does (6); 

~  3 Streams Farm Jersey cow and calf (2).

Offer above livestock groups unlimited weighed amounts of leaf-silage throughout 1 hr. before usual morning and evening rations, running 3 consecutive 4-week trials in winter: 

4-day leaf-silage adjustment period and 10-day leaf-silage trial, then 

4-day adjustment to no leaf-silage and 10-day no-leaf-silage trial.  

Weigh hay provided during each 10-day leaf-silage and no-leaf-silage trial.  At end of each 10-day trial, weigh hay remaining in mangers; subtract to record hay used/trial; 

  • Compute mean and range of hay-use with and without leaf-silage.  
  • See ** under d. below.

Weigh milk yields from 3 Streams cow and goats;

  • Chart yield/day/head with/without leaf-silage.
  • Summarize mean and range of yields with/without leaf-silage.

d.  Short Cattle Trials:  

~  Faithful Venture Farm 1-2.5 yr.-old Holstein heifers (10-12);

~  Meadowsweet Farm Angus cattle (5).    

Offer cattle unlimited weighed amounts of leaf-silage throughout 1 hr. from 6-7 AM each day for 1 week/group in winter. 

**Leaf-silage Trial-methods for c. and d. above:

Preceding down the livestock group’s barrel label-number list, start by drawing equally from 3 sequentially-listed barrels per meal, re-sealing, using same 3 barrels for multiple meals until one is empty, then using next 3.  Return to left-overs from top of list if end of list is reached.  

Offer in 3 deep feed dishes or troughs, keeping offerings from each barrel separate.  

Start by offering generous amount based upon observations during adjustment periods at Yknot and 3 Streams Farms, then based upon prior days.  Observe; add/note weighed (hanging scale) amounts from a barrel each time the corresponding dish/trough is emptied.  

Subtract weight leaf-silage left at hour’s end from leaf-silage offered (per barrel’s assigned dish/trough).  Compute/record total leaf-silage weight consumed and mean intake/head at each mealtime.    

  • Compute/report mean and range (across days) of daily leaf-silage intake/head, per livestock group.
  • Discuss nutrition of these animal intake findings, using 2.b. above.  
  • Compute means and ranges (across all days/barrels, and across days for each barrel) of 1 hr. leaf-silage intake/head/barrel, per livestock group; examine/discuss barrel preferences in relation to tree/shrub species tallies.

5.  Compare leaf-silages to other available forages.  

    • Chart mean and range/forage type:  cost inc. labor-time/DM; animal intake DM/head/day/livestock group; nutritional results per 2. above; yield/acre.  
  • Discuss farmer-participant experience/observations from leaf-silage harvest and livestock trials.     


Participation Summary
Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.