Winter Willow: A Simple, Science-Backed Boost for Your Livestock

When the grass has given up, gateways are a write-off and everyone’s a bit fed up of bale rings, winter feeding can start to feel like damage limitation rather than good stockmanship.

One low-tech, high-science option that’s getting serious attention is feeding willow (Salix viminalis) as a supplement alongside the usual forage and concentrates – especially for pregnant ewes, cattle, goats, horses and even poultry.

Tree fodder isn’t a new idea, but we’re finally getting the research to back up what stock have been telling us for years: they love browsing, and it can be good for them too. (Woodland Trust)

Below we’ll look at the benefits of willow for wintering livestock and how you can use coppiced willow on your own farm.

Willow Catkins

What’s special about willow (Salix viminalis)?

Fast-growing willows like Salix viminalis (often used in short-rotation coppice) produce a lot of leafy, twiggy biomass with a nutritional value surprisingly close to decent grass forage. Trials with sheep, goats and deer found that osier willow (S. viminalis) was highly digestible and readily eaten, with intakes comparable to conventional forages. (Cambridge University Press & Assessment)

Analyses of tree fodder leaves show: (ScienceDirect)

• Useful protein levels – handy in late pregnancy and early lactation.

• Good fibre – helping keep the rumen working and animals content.

• Vitamins A, C and E – supporting immunity and general health.

• Macro and trace minerals – including calcium, magnesium and others important for bone, muscle and metabolic health.

In other words, willow isn’t just “a bit of roughage” – it’s a genuine forage, and a useful extra mouthful in the winter ration.

Condensed tannins: tiny compounds, big benefits

One of willow’s “secret weapons” is its content of condensed tannins (CTs). These plant compounds have a mixed reputation, but at the right levels they’re incredibly useful.

Research on willow and other tannin-rich forages shows that: (BioMed Central)

• CTs can bind to dietary protein in the rumen, stopping it being broken down too quickly.

• More of that protein then passes into the small intestine, where the animal can actually use it for growth, milk and colostrum, rather than blowing it off as ammonia.

• Moderate tannin intake (around up to 5% of dry matter) can improve liveweight gain, wool production and reproductive performance, and reduce the impact of gut worms in sheep and other ruminants.

  
  

Too much tannin can depress intake and reduce digestibility – so we’re talking supplement rather than “feed nothing but willow and hope for the best”. (The Organic Research Centre)

Natural backup for worm control

Internal parasites remain one of the biggest losses in sheep and youngstock, and drench resistance is now a fact of life on many farms. Researchers have been exploring willow as part of a more sustainable worm-control strategy.

Several studies have found that feeding willow to lambs and young sheep: (ScienceDirect)

• Reduces gastrointestinal nematode burdens, especially species like Haemonchus contortus and Teladorsagia circumcincta.

• Halves total daily egg output in some trials, compared to control diets.

• Lowers worm fecundity (eggs per worm), making contamination of pasture slower.

Work with goats using willow extracts or protected fats (calcium soaps) has shown similar reductions in nematode load alongside normal nutrient intake and rumen function. (SpringerLink)

Willow isn’t a replacement for your vet-designed parasite plan, but it can support it – especially useful:

• When pregnant ewes are under pressure in late gestation.

• For grazing lambs and youngstock in the high-risk season.

• Where you’re trying to slow resistance by reducing drench frequency.

A bit of built-in pain relief

Willow bark famously gave us salicin, the natural precursor of aspirin, and willow foliage is rich in salicylic compounds. (Innovative Farmers)

We’re not talking about DIY veterinary medicine here, but tree-fodder factsheets note that browsing small amounts of willow can provide mild anti-inflammatory and pain-relief effects, and may help animals cope with minor aches, knocks and inflammatory processes as part of routine life.

Again, this is a support, not a substitute for proper treatment – but it’s a nice additional string to willow’s bow.

Species-by-species: who benefits, and how?

Sheep – especially pregnant ewes and young lambs

For sheep, willow ticks several boxes:

• Extra protein and minerals in late pregnancy and early lactation, when demand is highest. (ScienceDirect)

• Condensed tannins that can improve protein use and reduce worm impact by up to ~50% when included at sensible levels. (The Organic Research Centre)

• Behavioural benefits – browsing is a natural behaviour; animals are typically calmer and more settled around living or fresh-cut browse. (Woodland Trust)

Practical ideas:

• Offer cut willow bundles in troughs or along a fence in late gestation and through early lactation.

• Use coppiced willow blocks as a “browse break” when ewes are coming off poor leys or rough ground.

• With twins/triplets, willow can be a nice way to lift the ration slightly without overdoing concentrates.

Cattle

Trials with beef cattle grazing willow showed: (docs.eaap.org)

• Similar total dry-matter intake from willow versus good grass when offered ad lib.

• Lower liveweight gain compared with top-quality grass (so willow is a supplement, not a magic rocket-fuel forage).

• Methane emissions per day reduced by up to 27%, thanks to tannins altering rumen fermentation, without increasing methane per kg liveweight gain.

  
  

For store cattle and suckler cows, willow browse can:

• Add feed diversity during the winter.

• Provide shelter and shade when planted in alley or shelterbelt systems. (Woodland Trust)

Goats and deer

Sheep’s more agile cousins are natural browsers and often go for willow first. Studies measuring intake and digestibility found high voluntary intake and good utilisation of S. viminalis and related willows by goats and deer. (Cambridge University Press & Assessment)

For mixed grazing systems, willow blocks can be a very efficient way to keep goats and deer occupied and well-fed over winter.

Horses

Evidence in horses is more traditional and practical than trial-based, but:

• Many horses readily eat willow leaves and twigs, especially when turnout is limited.

• It offers chew time and interest, which may help with stable boredom.

• The natural salicylates are again thought to have mild soothing effects. (Innovative Farmers)

However:

• Keep an eye on overall sugar and starch in the diet for laminitis-prone animals – don’t assume “tree” automatically means low NSC.

• Introduce slowly and in moderation, and discuss any regular use with your vet, particularly if the horse is on medication.

Poultry

Chickens won’t live on willow leaves alone (and shouldn’t), but in tree-rich poultry ranges they’ll: (Woodland Trust)

• Use willow for shade, shelter and wind protection in rough weather.

• Peck at leaves, bark and the invertebrates living on and under them.

• Show more natural foraging and exploratory behaviour, which reduces feather-pecking and boredom.

  
  

In practice, the main benefit for poultry is welfare and microclimate, with any leaf intake a small nutritional bonus.

Pigs

Although pigs are classic rooters rather than browsers, many will happily chew willow branches when offered — especially younger stock or traditional breeds with a stronger foraging instinct.

Benefits for pigs include:

• Enrichment and behaviour: Willow branches provide chew-time, occupation and stress reduction. This is especially valuable for pigs kept indoors over winter or during wet periods when outdoor rooting is limited.

• Trace nutrients & roughage: While pigs won’t consume willow in the same quantities as ruminants, the leaves and thin twigs add small amounts of fibre, minerals and vitamins.

• Tooth and tusk wear: Regular chewing can help maintain tooth health and reduce excessive tusk growth in boars.

• Natural anti-inflammatory compounds: The salicylates in willow may offer mild soothing effects, though not at medicinal levels.

Practical notes:

• Offer bundles of willow branches as occupational enrichment, not a feed replacement.

• Avoid large, hard stems for small pigs.

• Remove heavily fouled branches to maintain hygiene.

• Make sure pigs still receive a balanced ration — willow is a behavioural bonus rather than nutrition-heavy feed.

Llamas & Alpacas (Camelids)

Camelids are natural browsers and often seek out shrubs, young trees and leaves — which makes willow a welcome winter addition.

Benefits for llamas and alpacas:

• Highly palatable browse: They will readily strip leaves and tender bark from willow rods.

• Fibre for gut health: Additional roughage supports a steady digestive system, especially useful in winter when grass quantity and quality drop.

• Trace minerals & vitamins: Willow offers a light nutritional lift that supports general condition.

• Parasite support: While research on camelids is limited, the condensed tannins found in willow have shown positive effects in related browsing species and may help reduce worm burdens as part of a wider parasite strategy.

• Mental stimulation: Browsing reduces boredom, improves welfare and imitates natural foraging behaviour.

Practical notes:

• Introduce gradually, especially to animals not accustomed to browse.

• Avoid offering huge volumes — camelids should still rely mostly on hay and pasture.

• Provide plenty of clean water, as higher tannin feed can increase water intake.

• Place willow bundles in racks or hung from fences to keep them clean and engaging.

How to use willow with overwintering livestock

You don’t need to convert the whole farm into a forest to get started. A few practical options:

1. Dedicated fodder blocks

Plant short-rotation coppice blocks of Salix viminalis (or suitable hybrids) in accessible spots. Once established, you can:

• Cut and carry rods into yards, lambing sheds or loafing areas.

• Strip-graze standing coppice, letting animals browse regrowth during late autumn and early spring.

• Rotate access to avoid over-browsing and allow stools to recover.

2. Hedgerows and shelterbelts

Incorporate willow into:

• New hedges or gappy old ones.

• Shelterbelts across exposed fields.

You get shade in summer, shelter in winter and a regular source of browse, all while ticking plenty of agroforestry and biodiversity boxes. (Woodland Trust)

3. Lambing and calving support

Cutting willow ahead of time gives you:

• A clean, fresh, fibrous supplement to offer alongside hay or silage.

• A useful tool when appetite is off – some animals will pick at browse when they’re less keen on other feeds.

Just keep it as an addition, not the entire ration.

How much willow is “enough”?

Because willow is relatively new in mainstream UK rations, there isn’t a single magic figure. But the research on tannin-rich forages gives us a useful guide: (The Organic Research Centre)

• Up to around 5% of total dry-matter intake from condensed tannins is generally beneficial for protein use and worm control.

• Beyond that, performance may start to drop as tannins bind too much protein and reduce digestibility.

In practice, that usually works out as willow making up a minority share of the daily intake – think “a generous side-serving” rather than the whole plate.

Safety notes and common-sense management

A few sensible precautions:

• Introduce gradually over 7–10 days so rumen microbes can adapt.

• Always offer willow alongside normal forage (hay, silage, grass) rather than instead of it.

• Make sure stock have access to a balanced mineral source – willow is good, but it’s not a complete premix. (ScienceDirect)

• Avoid letting hungry animals ring-bark young stools – use temporary electric or guards until stools are well established.

• Remember: some trees are toxic to livestock; willow is generally safe when fed sensibly, but don’t let stock at unknown ornamental species without checking first. (Innovative Farmers)

And as always, talk to your vet or nutritionist before making big changes to the rations of high-value or high-risk stock (pregnant ewes, fresh calvers, laminitis-prone horses etc).

Why willow fits so neatly into winter on UK farms

From a farm business point of view, willow fodder offers:

• A home-grown, low-input feed that keeps producing for years once planted.

  Added resilience in dry summers and wet winters, when grass lets you down.

• Potential reductions in worm pressure and methane output, backed by peer-reviewed research. (BioMed Central)

• Better welfare and behaviour, from ewes to hens, simply by letting animals do what they evolved to do: browse.

If you’d like to experiment with willow for your own flock or herd, the easiest way to start is with a small fodder block or a short run of willow in a hedge or shelterbelt. Once it’s away, you’ll quickly learn how your stock use it – and many farmers find they’re soon planning where to plant more. Our tip is to use those damp wet non-productive corners first.

Plant Your Winter Willow Today

Ready to add willow to your winter-feeding toolbox?

Bowhayes Trees Ltd supplies high-quality willow varieties ideal for livestock fodder blocks, hedgerows, shelterbelts and sustainable farm planting.

• Fast-growing Salix viminalis varieties

• Expert advice for farms, smallholdings and estates

• Bulk quantities and tailored planting packs

• Bundles of willow for 'trial' with your livestock

  
  

Browse our willow range and order online today at www.bowhayestrees.co.uk.

Or get in touch for friendly, practical advice on designing your own fodder block or agroforestry system.