Windbreaks and Shelters for Cattle
In climates where wind chill can be an issue during colder months, planning ahead for winter weather can save money (in reduced feed costs, reduced illness and health costs, less loss of body condition—and better gains on young animals). When the wind and cold stress the cattle, they seek shelter.
NATURAL WINDBREAKS –
Some regions have woods and trees, gullies and draws, where cattle can get out of the wind. In other areas there’s not much to stop the wind. Karl Hoppe, Extension Livestock Specialist (North Dakota State University Carrington Research Extension Center), has been involved with cow-calf and feedlot management for 34 years and says North Dakota is a prairie state that gets a lot of wind. “If we need natural windbreaks, we have to grow them. We have Soil Conservation Districts that plant conservation-grade windbreaks like 7 to 15 rows of trees, but if you need a windbreak, this will take about 20 years. You have to plan ahead for trees. With that kind of windbreak, however, you also need to do regular maintenance. There are always a few limbs that blow down or trees that die and need removal,” Hoppe says.
“Trees are great for slowing down wind but they also catch snow. If snow is drifting, it will drift in those windbreaks and keep that snow out of cattle pens next to them. This can greatly reduce the snow load in your pens.”
There is also a downside to this. “If you have windbreaks all the way around your whole farm barnyard and pens, in the summer on a hot day when you need a breeze, it can get too hot for livestock. In North Dakota we usually only put windbreaks around the northwest corner—on the north side and west side—and not the south side–buy there can sometimes be a cold, wet south breeze and then the cattle have no protection,” he says.
Kiernan Brandt, Extension Cow-Calf Field Specialist for South Dakota State University, says natural windbreaks (trees and brush, shelterbelts, etc.) can give cattle a lot of protection in a winter pasture. “For a shelterbelt, you’d plant a mix of species—some that are tall, some medium height and some that are low to the ground,” he says. This will maximize the area of shelter.
“There are several ways to go about it, depending on where it will be. Sometimes you’d plant multiple rows, and spaced out, to allow those plants to grow and mature without crowding. You don’t want them too close together or too dense; it’s best to have a little space in between so some air can actually pass through. This will increase the area of coverage on the downwind side,” he explains. You want the trees to slow the wind and not stop it completely.
“If it is too tight, the wind doesn’t have any way to slow down and pass through and will just go around it. Sometimes a strong wind will even go faster as it whips around the end of it. This can increase drifting and may create drifts over roads,” he says.
You might add a few evergreens to the mix, so there will be something with a lot of branches and wind protection after other trees have shed their leaves. “When planning a shelterbelt, talk to someone in Extension or NRCS or other experts to make sure you are using the right blend of species that will give the best coverage,” says Brandt.
You also want to select plants that will do well in your climate and region, and that might be beneficial to wildlife. Make sure you are not introducing any noxious plants or any that might be detrimental to what you are trying to accomplish.
“It helps to put some thought into this, when creating something permanent—whether a natural or manmade windbreak—regarding where it should be and to make sure it will be beneficial for a long time. You don’t want it to create drifts over roads or paths, or in front of grain bins or hay sheds that you need to get to,” he says.
Situate a windbreak where it will give the most protection from prevailing winds. “Here in South Dakota we get a lot of our winter weather out of the northwest. Having a windbreak in the northwest corner of a pasture is usually best, so the animals can graze into the storm and get behind the windbreak and it won’t be in the way of them using the space in that pasture or pen,” he explains.
Deciding where to put windbreaks can be a challenge. In some cases it comes down to using portable or temporary windbreaks, like big straw bales.
ARTIFICIAL WINDBREAKS –
You can utilize many materials when creating a man-made windbreak. “Anything heavy-duty that utilizes material that will hold up to strong winds (and cattle rubbing) will work. Windbreaks on high points or exposed faces where there will be heavy wind or strong gusts must be sturdy,” says Brandt.
“Wood posts need to be set 3 to 5 feet deep—below frost line—or they may work up out of the ground with frost heaves. Wood posts should be about 8 inches in diameter. Large drill pipe (6 to 8 inches) will also work nicely,” he says.
The amount of area you need to cover will determine what you use to create the windbreak. “We use the rule of thumb of 25 square feet per cow,” he says. The height of the windbreak helps determine the distance of protection behind it.
“Another way to look at it is to estimate about 1 foot of fence per animal, so however long your windbreak is will determine how many cattle can be protected behind it,” says Brandt. This is a good rule of thumb for figuring out how long the windbreak fence should be in order to accommodate a certain number of animals.
“Whenever you build windbreaks, permanent or portable, the rule of thumb is that each one foot vertical provides 10 feet of downwind protection,” says Hoppe. If you have an 8-foot tall windbreak it will reduce wind speed for about 80 feet in a triangular shape, diminishing as you get farther out.
“When you plan for the space, you need to think about how much space a cow needs, to lie down. If she needs about 3 feet by 8 feet that means 24 square feet, so you probably need at least 20 square feet per cow. If you have an 8-foot tall windbreak, you need to determine how wide it should be, for a group of cows. One board 8 feet high will not give enough protection, so you need a series of boards,” Hoppe says.
Whatever you attach to the posts should have some gaps–between the boards or tin. You need some spaces (porosity) for air to pass through. You also need about 20% porosity, with space between the boards. “If you need 20%, that would be an inch of space between every 1-by-6 inch board, or bigger spaces between bigger boards. The wind will come through there fairly fast, through those slots, but as soon as it gets about a foot away from the windbreak, the air is gone and it loses that velocity. Beyond that is a large area where it’s fairly calm and where cattle like to stand or bed,” Hoppe says.
“This actually works well, because that cold area right by the fence keeps cattle from rubbing on it; they are not up tight against it. The windbreak should go clear to the ground or the wind will blow underneath it, unless that space fills up with snow, manure, bedding, etc. You might have it off the ground a little, but you wouldn’t want it much off the ground or the wind will rush through.”
Brandt advises people to leave a gap at the bottom, to allow some air to pass through along the ground. “If it is solid all the way to the dirt, there will be more risk for drifts. By having some porosity, and especially by leaving a little open space at the bottom, we allow wind to pass through—after it slows down.” This keeps snow from building up in front of it, or dumping in a big drift on the downwind side after the wind goes up over the windbreak. A big drift in front of the windbreak may take a while to melt in the spring, and if it is piled against a wooden structure the snow can keep it wet for a long time and damage the wood.
“When planning any structure, give some thought about where the snow will collect after you redirect the wind. You want it out of the way so that when drifts melt the moisture can drain away and not cause problems with mud. This is the also important for leaving some open spaces and not have a completely solid structure that would create bigger snowdrifts than would occur in an open area,” says Brandt.
It helps to know how the land lies, where the water drains, where the animals like to gather, where they have to go for water, where you need to go to take feed to them during severe weather, etc. Take time to plan the initial site for a windbreak.
Windbreaks don’t have to be permanent. Even a stack of big bales (hay or straw) can provide a lot of protection, stacked along a fence. “This works well, especially if the cattle are fed enough that they are not trying to crawl through the fence to get to those bales. Cattle have a lot of protection if they are behind a 90-degree corner of bale stacks. This can make a great windbreak in a pinch. I’m from southern Wyoming, and we get a lot of wind there; people many different things to create windbreaks.
I’ve seen windbreaks made with old power poles, chiseling the ends to fit them together like Lincoln logs or a worm fence. The main thing for something like that is to bolt them together so they can withstand major gusts of wind and won’t come apart or tip over.”
A person can also make portable windbreaks that can move with a skid steer or tractor. “These work well, as long as they are heavy enough to withstand wind. They need a strong, wide, heavy base. The base should probably be 1.5 times the height of the structure. A 10-foot tall windbreak would need a base about 15 feet wide,” Brandt says.
Hoppe says they do freeze down (and can be harder to move), and wind can also flip them over if you don’t have them staked down securely. There are several designs and some have enough counterweight that they don’t tip over very readily.
“My neighbor has windbreaks situated at right angles, with 5 panels going one direction and 5 panels going the other direction. The very end panel will flop, however, if you get a really strong wind. The others wouldn’t, unless the end panels started to pull them over. Make sure to anchor the end panels,” Hoppe says.
Windbreaks can do a lot to minimize cold stress. Wind chill charts show what the difference is (the colder effect caused by certain wind speeds at various temperatures). With no wind, temperatures below thirty degrees create a need for more feed for cattle, to generate the energy necessary to keep warm. “Every 10 degree drop due to wind chill will be about a 13% increase in feed just for the animals to maintain body heat. If it is 30 degrees outside, with a 20 mile-per-hour wind, the energy requirement for that cow will go up by about 25%. We need to make sure we have enough space behind a windbreak to protect the majority of our animals at any given time,” says Brandt.
“In South Dakota, we get weeks and sometimes months of severe weather, so it doesn’t take long for a windbreak to pay for itself, in feed saved.” Otherwise cattle must eat more or will be losing weight, at a time of year you don’t want them to lose weight.
“Calves are very susceptible to severe weather, whether heat or cold. During hot weather in summer, windbreaks also create some shade. This is very important here, where we have a lot of crop integration in our livestock systems. Many people raise corn and soybeans as well as cattle, and those fields have no natural shade. We tend to think of windbreaks as winter precautions but they have a lot of benefit throughout the year.”
Some of the windbreaks used in a feedlot can be converted to shade structures in summer. “These work well as long as there is some porosity so air can go through them. You don’t want a solid structure that would hinder any cooling breeze in summer. The nice thing about portable windbreaks is that they can move from pasture to pasture with the cows. These are great when cattle are on cornstalks during winter or any farm ground. Having something that you can pick up and move from one pivot to the next can be very beneficial,” Brandt says.
Permanent windbreaks made of wood have been used for many years, but now many people make them out of metal strips, vertically or horizontally. They last a long time, but if cattle rub on them or machinery hits them accidentally, bending or damaging them in turn. “Cost-wise, it’s about a tossup between wood and steel unless you are in location where you can get cheap slab lumber,” Hoppe says.
“My colleague Vern Anderson, now retired, did a project with windbreaks and was able to show that the marbling, performance and average daily gain in cattle were better when there was a windbreak provided, versus no windbreak.” The cattle don’t have to utilize as much energy just to keep warm. If you can increase their comfort level they respond by putting on more weight and adding more marbling, which makes the carcass worth more.
“Some people put out bedding for their cattle, and if a windbreak is set at an angle, there is a spot at the bottom that baby calves can crawl into and bed and not risk the cows tramping or laying on them. A person can also put a bar there so the cows can’t get in where the calves are,” says Hoppe. There are many designs that can be beneficial.
Some ranchers put cows in a barn during a severe storm. The barn needs some ventilation, however, or there will be too much moisture in the air—which is not a healthy situation. “When I was a kid growing up in Iowa we had a cattle barn with a manger in the middle filled with hay and the cows would be on both sides of it. You could walk in there at 20 below zero and all the cattle would be standing by that manger and there was frost everywhere—on the spider webs and everything—because the cows were breathing out so much moisture. Cattle like being indoors in cold weather but that moist warm air is not healthy,” Hoppe says.
“You need a breeze to provide adequate ventilation! This is where a forest of trees is the best windbreak. Cattle have fresh clean air and can find a spot out of the wind that is comfortable—and hopefully don’t eat pine needles and get pine needle abortion!” When planting a windbreak, evergreens are nice, as long as they are not ponderosa pine.
There are many options when it comes to windbreaks and a person can usually come up with something that works, or do something innovative to fit their own situation.
The main thing is to prevent wind chill, especially if the cattle are wet from rain or a winter storm with wet snow. If their hair gets wet and moisture gets clear down to the skin, they lose their natural insulation. Strong wind that blows the hairs apart also reduces the insulating effect of a good winter hair coat.
“Cattle can stay pretty warm as long as the wind isn’t blowing through their hair or they get wet. Nothing is worse than 34 degrees with rain, on newborn calves. They chill immediately (partly because they don’t have much body mass to retain adequate core temperature). Snow is better than a cold rain,” says Hoppe.
CALF SHELTERS –
Every year a few young calves die from hypothermia resulting from cold rain or cold, windy weather. Prevent these losses by providing shelter in pastures that don’t have natural windbreaks.
There are many designs for calf shelters, and many innovations for creating little “houses” from all kinds of materials. Dr. Ron Skinner (veterinarian and cattle breeder) made skids and crosspieces for his calf hutches from 6-inch well casing obtained from a salvage business. “We can push or drag these shelters anywhere and they won’t break. The well casing is stiff enough to drag or push over frozen cow manure. We used vertical metal pieces and framed it with angle iron, bolted boards to that, and put a metal roof on the frame,” Skinner says.
His hutches don’t have floors. If the ground or bedding starts to get dirty, he pushes the building to a new location when feeding cows. “My tractor has two forks on the loader for handling round bales, and I just slide those tines under the end of the hutch, pick it up a little and slide it any direction. I can roll some straw off a round bale into the hutch, for new bedding,” says Skinner.
On our ranch, my husband designed and built our first calf house in 1968, then built several more. Each of these long, narrow shelters (8 by 16 feet) can house about 20 calves and is built on runners to easily move to a different location if necessary. Each house has a sloping galvanized metal roof (higher in front) and a floor. This keeps calves up out of the mud or melting snow run-off that may flow across a field. The floor has slats, so urine runs down through it, and bedding stays drier. The floor also makes the house more durable (it holds together better when it moves) and adds weight so it can never be blown over.
The front of the house is partly closed, with opening low enough to keep cows out, and help hold warmth in (the body heat of several calves can make the house warmer) and keep cold breezes out. Cows might reach in to eat bedding and there is also risk of a calf being stepped on or laid on if cows congregate in front of a house. We keep the front area yarded off with pole panels or an electric wire, so calves can come and go, but the cows cannot get to it.
An instant calf shelter can be made with big straw bales (with mesh panels along the sides to keep the cows from eating the outside surfaces) and a tarp roof. Position Pole panels or portable corral panels in front so calves can get in, but cows can’t. This can be a very effective shelter in an emergency or whenever you don’t have time to make a permanent shelter.
by Heather Smith Thomas
