Introduction

1. Winter grazing reduces feed costs by extending pasture use and minimizing stored feed needs.  

2. Understanding your flock’s nutritional needs and maintaining proper Body Condition Scores (BCS) are crucial for winter grazing success.

3. A variety of forages can be winter grazed including crop aftermath, seeded crops or cover crops, and stockpiled grasses.

4. Sheep are well-suited for winter grazing and capable of digging though snow to reach covered feed.

5. Simple equipment like electric netting and battery-powered fence chargers ensure safe and efficient winter grazing.

 

Our Story

The idea of winter grazing in snowy northern regions was practically unheard of until only a few decades ago.  But it wasn’t until we moved our ranch 150 miles east, where our land base favored this model, that we could apply it to our beef cattle and sheep operation. 

Our experiment started with custom winter grazing our ewes on alfalfa and alfalfa-grass hay fields September through March.  We negotiated our first agreement with a hay grower to “sheep off” the regrowth after the last hay cutting was harvested for the year.  This arrangement began a 19-year relationship that led us to many other opportunities to graze alfalfa fields, volunteer grain, cornstalks and veggie aftermath for other growers.  These agreements were with farmers who were happy to have the sheep remove the excess vegetation from their fields, saving them time labor and equipment use.  It was a win for our sheep, our farmers partners and us.

Understanding Nutritional Requirements for Ewes

Successful winter grazing depends on understanding the nutritional needs of your sheep.   Mature ewes have different needs than growing, weaned feeders or fat lambs.  Even the nutritional needs of breeding females can vary widely depending on their physiological stage.  A lactating ewe with twins has a tremendous energy requirement, which is needed to produce milk and maintain her body condition.  By comparison, a pre-breeding dry ewe has a relatively low energy requirement.

Nutritional needs can vary within breeds of sheep and even within individuals.  Highly prolific breeds, such as Finnish Landrace or Polypays, require a higher plane of nutrition than fine wooled range ewes such as Targhees.  Individuals within your flock may convert forage to fat easier than others. If you intend to build a flock that thrives in a variety of grazing conditions, it is worth noting what ewes maintain their weight and which don’t.

Table 1:  Nutrient Requirements of Sheep  

Importance of Body Condition Score (BCS) in Winter

Both you and your sheep will have a clear advantage if your animals enter the winter months with a proper Body Condition Score.  A Body Condition Score measures the subcutaneous fat that a ewe or lamb carries under their skin.  A ewe with an optimal BCS of 2.5 to 3 will have advantages going into the winter that her thinner sisters will not.  She will have the fat for insulation and energy to protect her from inclement weather and to burn when feed quality decreases.  She will also have higher quality colostrum and better milk yields at lambing time—two important factors for lamb survival. 

Table 1 (above) can be used as a guide to help you determine two key nutritional requirements for your flock.   We are most concerned with the macronutrients Crude Protein and Total Digestible Nutrients.  Crude Protein (CP) measures a feed’s total protein content.  Total Digestible Nutrients (TDN) measures energy within a feed. If you know your flock’s nutritional requirements and your feed’s CP and TDN, you have a good foundation for providing your flock with a balanced diet.

Types of Winter Forage For Sheep

Forage for winter grazing can be divided loosely into three categories.

• Crop aftermath or crop residue
• Seeded crops and cover crops
• Stockpiled perennial grasses and legumes

Grazing Crop Aftermath or Crop Residue in Winter

This category of feeds includes a wide variety of forages and plant materials.  Our original contracts were for grazing alfalfa regrowth post-harvest.   Our ranch is in a large alfalfa growing region that produces hay and alfalfa seed, so we have access to acres of alfalfa in the fall. Because of the late fall regrowth and the relatively mild winters, grazing alfalfa all winter became a staple in our grazing program.

Examples of crop aftermath or residue include:

• Alfalfa hay regrowth
• Wheat or barley stubble
• Volunteer regrowth from small grains
• Corn residue
• Fall vegetable residues such as pumpkins, squash, carrots, and cruciferous vegetables, including kale, cabbage, and broccoli.

A significant advantage of grazing crop residues is that these forages allow enterprise “stacking.”  A crop is harvested for cash and later harvested with livestock as feed.  The downside of crop aftermath is that it is not always consistently available.  Weather and irrigation water influence the regrowth of alfalfa and volunteer grain.  Harvesting techniques can affect how much residue remains after removing the wheat or barley and vegetable crops during harvest.   Nutritional content can vary widely so consider forage testing feeds for accurate CP and TDN content.

Ewes grazing on a seeded cover crop beneath the snow on a cold January day. 

Utilizing Seeded Crops and Cover Crops for Sheep Grazing

Cover crops seeded for winter consumption can provide an extended grazing season through the early fall and winter.  Because many of these crops are cool season plants, they withstand the cold temperatures and, in the right situations, can persist all winter.   Once established, these crops make exceptional feed for flushing breeding ewes and growing or fattening young stock. 

Examples of seeded crops in this category include:  

• Turnips
• Kale
• Rape
• Triticale
• Rye
• Vetch
• Winter wheat
• Annual ryegrass

Turnips grow a high protein top and a high energy bulb that sheep will readily dig out of the ground to eat.  Purple top turnips paired with a small grain make a nutritious feed mix with the added benefit of improving soil health.   

Annually seeding these forages for winter grazing will produce a predictable, high-quality feed.  Many of these cover crop plants also produce high dry matter per acre.  Though these plants are all cold tolerant, they will winterkill if temperatures reach extreme lows.

Benefits of Stockpiled Perennial Grass for Winter Graze

If you have perennial pastures, you can potentially stockpile forage for winter feed.  Accomplishing this requires a careful grazing plan to ensure that your stock density and grazing intervals are optimized.   Stockpiling grass for fall and winter grazing requires standing forage in adequate quantities and quality to meet the nutritional needs of the flock.  

Examples of stockpiled forages include:

• Orchardgrass
• Tall Fescue
• Perennial ryegrass
• Alfalfa

Cool season grasses may continue to grow into the fall, but growth will eventually slow to a point where plant recovery is limited.   Overseeding grass stands with clovers, annual grain or grass improves the quality and quantity of the graze. 

Winter grazing usually requires sheep to graze a paddock once during winter to protect the field for future use.  To protect the fields for the following spring grass, shepherds must ensure that sheep are moved regularly to fresh feed to prevent permanent damage to the forage stand, particularly in wet conditions. 

A snowy 23 acre Orchardgrass field supported 215 ewe lambs for several weeks with no supplemental feed.

Effective Sheep Management During Winter Grazing

Protecting Sheep Against Cold Stress

Sheep are ideally suited for winter grazing.  When in full fleece, they are hardy and resist the coldest temperatures.  As long as ewes are dry, they can maintain body temperatures when outside temperatures reach 25 ‘F or lower.  Not only do they benefit from their thick wool coats, ewes in the proper body condition have a layer of subcutaneous fat (fat located just under their skin) that also protects them against the cold.  

A ewe is full fleece rarely will show signs of cold stress in still, chilly weather. Since snow stays on the exterior surface of her wool and does not reach her skin, she doesn’t lose significant body heat.  When conditions become wet and rainy or wind and driving snow forces the wind chill to dangerous levels, sheep can exhibit signs of cold stress. Stress occurs when animals cannot cope with a negative environmental factor, such as extreme hot or cold temperatures. Protection from extended periods of cold rain is crucial. Soaking rains can saturate the fleece allowing moisture to reach the sheep’s skin, making it difficult for her to maintain her body temperature.   These conditions require extra feed and shelter for protection from the elements. 

Providing Shelter and Windbreaks

As a responsible shepherd, winter grazing requires you to prepare for inclement weather.  Know your climate and what challenges you may face.   A windbreak of hedges, trees, or a man-made break to protect sheep from cold winds may be adequate.  We have used 4 X 4 big bales of straw to create a wind break in our very windy early springs.   An open or three sided shed can provide shelter during these times with less concern for high indoor humidity, which can create an environment for pneumonia.  

Shelter may not be necessary in climates with milder winters.  Our ewes enjoy an arid, cool climate that is perfect for winter grazing.  We experience a few days of wet, muddy conditions when the ground thaws after a freeze, but the majority of the time, we have little concern for mud.

Ewes will readily paw with their front feet to reach the feed beneath the snow.

Managing Snowy Conditions

Snowy conditions can create their own set of challenges for livestock producers.  Snow depth, texture, water content and soil conditions can influence grazing success.  

Impact of Snow Depth and Texture on Grazing

Sheep readily dig through snow to reach feed.  Our ewes have grazed through snow 10″ deep, though we supplement them with hay to ensure adequate feed is available.  Sheep grazing in 4 to 6 inches of snow have no trouble uncovering enough forage to meet their daily dry matter requirements.  

Snow texture may be a more critical factor than snow depth.  Soft, dry snow is easy for sheep to dig through, and they will readily do so. But as snow melts, particularly wet snow, it can become heavy and icy, making it difficult, if not impossible, for sheep to reach the feed lying underneath.  You may need to supplement with hay until the snow melts and the feed is exposed.  Another alternative is to move the flock to a field with taller forage that is exposed above the snow.

Providing Water from Snow for Sheep

Depending on the forage moisture levels and the availability of soft snow, ewes often ignore the water trough during the winter. Sheep will consume snow as their primary water source if it is not too hard or icy for them to bite. You may observe them reaching down to lick small quantities of snow to meet their hydration needs. They frequently consume small amounts of snow in quick “sips” rather than taking larger quantities of icy water from a trough.   The ewe’s body uses less energy to heat snow and it has less of a chilling effect than cold water. 

Snow contains only 4 to 10% water, so keep a full water trough readily available for sheep to visit if needed.  Providing fluid water is still essential during cold weather, particularly if it dry.  Breaking ice or heating troughs will ensure sheep can get to additional water.

Sheep require access to clean, fresh water at all times. Water is the most critical nutrient for the health of your flock. Inadequate, frozen or fouled water will limit water intake, reducing growth and compromising the immune system.

 

Freezing weather, cold water and hard snow can reduce your flock’s water consumption and animal performance.  Decreased water consumption leads to stress, which suppresses the immune system and exposes sheep to disease.  

Ewes are digging turnips and kale from beneath the snow.

Grazing behaviors in winter

Depending on the weather, sheep will spend significant time laying and ruminating as part of their normal behavior.  On sunny winter days, you will see them lying around chewing their cud and soaking up the sun.  On snowy days, ewes often lie in one spot for hours, creating a depression where they rest as snow accumulates around them. 

Livestock, including sheep, can lose significant body heat from laying on cold ground.  Even though ewes in full fleece generally have some wooly insulation on their bellies, this wool is not as thick as the rest of their fleece.  The colder the ground, the more body heat a ewe loses through conduction.  

If your flock is grazing on cover crops,  stockpiled grasses, or leguminous plants, the standing forage will provide some protection from the frozen ground.  If they are in fields with less vegetation, such as a tilled field with row crop aftermath, their exposure to bare ground will likely be higher.  

When ewes must lay on frozen, bare ground, consider adding extra bedding to their enclosure. Even a layer of straw can decrease direct exposure to cold, frozen ground and create insulated areas for sheep to lay on.  

As temperatures decrease, sheep need to increase feed consumption to offset lost energy from the cold.  Ewes may need as much as 20% more feed intake to maintain body temperature in cold conditions.  Their increased feed intake must be taken into account when planning winter grazing. Sheep may move through paddocks faster due to increased feed requirements when temperatures drop. 

During severe weather, sheep protect themselves from wind by standing in a tight group where they spend little time grazing.  If weather prevents normal grazing, ewes will need to be provided with extra feed and shelter. 

Electric netting is notorious for catching loose vegetation (squash vines) during fall and winter wind storms.

Essential Equipment and Tips for Winter Grazing

Winter grazing equipment is straightforward. You can keep your sheep behind one to three electric wire strands or electric netting. In our experience, sheep need training to respect single strands. With a secure perimeter fence, a few electric strands can effectively divide your grazing area into paddocks.

Pros and Cons of Portable Electric Netting

Our grazing fields lack permanent fencing, so we rely completely on electric netting. It’s excellent at containing sheep and deterring predators and dogs. Since most of our grazing happens 15-25 miles from our main ranch, keeping sheep in is critical for us. Trust me, there’s nothing more heart pounding than a pre-dawn call about your sheep on the highway!

While water conducts electricity well, snow and ice don’t – they’ll short out your fence. That’s why we prefer portable electric netting. Even with a reduced charge from snow or ice, netting still provides a psychological and physical barrier to keep sheep in place.

Since we graze in areas without electricity, we use battery-powered fence chargers. We exclusively use deep cycle marine batteries with high cranking amps. Keeping three to four in rotation ensures we always have a fully charged battery. Our batteries typically last a week, even in frigid temperatures. Daily checks on sheep and fences make battery rotation part of our routine.

Invest in a quality fence tester to check your fence’s charge daily.  A tester that displays voltage lets you know exactly when your battery charge is weak and prevents your flock from taking sheep field trips.

Be prepared  to find loose vegetation and debris built up on your fence when winter winds blow . In our case, tumbleweeds, kochia or squash vines break fence posts and wires and short out fences.  Snowplows bury fences close to the road and fences laden with layers of ice bend posts and push entire lengths of fence to the ground. Snowy or icy conditions are part of the winter grazing challenge.  

When  temperatures freeze the ground, posts are difficult to drive in but much harder to get out.  Tapping the top of the frozen post can loosen the soil’s icy grip.  In preparation for predicted severe weather, we will fence paddocks ahead to avoid installing posts in hard, frozen ground or snow. 

When we don’t have access to a water sources, we haul water.  A 250 gallon tote in the back of our 3/4 ton pick-up works well for filling troughs when fluid water is not available through a hose or a stream. 

Deep cycle marine batteries and a ground rod help keep fences charged during cold weather. 

Economics of Winter Grazing

Cost Savings from Winter Grazing

An obvious benefit of winter grazing your flock is reduced feed costs, which in turn can increase profit margins.  Winter grazing allows you to utilize pastures longer, reducing the need for stored feed.  We calculate the savings for each ewe is approximately 750 lbs. of hay, depending on the year.  If the hay value is $200/ton, we save $75 per ewe.  Over 300 ewes, that is the equivalent of $22,500 per year. Our costs include fuel, labor, equipment replacement and, in some cases, modest grazing fees.  When all is said and done, we estimate our savings is still north of $15,000.   

Grazed ewes on proper feed should be in better body condition for lambing at the end of the winter.  Higher Body Condition Scores make for thriftier newborns and gives the dam needed body fat for good milk yields.  

Additional  Benefits of Winter Grazing

Not all winter grazing benefits are economic, but many contribute to the bottom line.

• Sheep remain cleaner and produce cleaner fleeces with little to no vegetation.    
• Respiratory infections decrease since your flock is outside, soaking in the sun and fresh air rather than in a damp barn.
• Grazing provides a cleaner environment and can reduce parasite transfer.
• Since ewes can graze all hours of the day, they tend to stay on a higher plane of nutrition if they have the proper feed.
• For the shepherd, grazing sheep means little to no daily feeding and reduced barn cleaning.  We move fence weekly. 
• And we can’t ignore the benefits of added soil fertility and better distribution of nutrients from grazing sheep.   

Winter grazing offers an incredible opportunity to enhance livestock management while reducing feed costs. You can make the most of this practice by understanding your flock’s nutritional needs, effectively managing winter forage, and preparing for challenging weather conditions. With the proper knowledge and preparation, winter grazing can be a game-changer for your operation.

Sources

Ensminger, M. E., & Olentine, Jr., C. G. (1978). Feeds & Nutrition – Complete (first). The Ensminger Publishing Company.

National Research Council of National Academies. (2007). Nutrient Requirements of Small Ruminants: Sheep, Goats, Cervids, and New World Camelids. The National Academies Press.

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