Winter Weight Loss

Keep your horse at a healthy weight during the cold months.

Keep your horse at a healthy weight during the cold months.

By Thomas R. Lenz, D.V.M., M.S.

Temperatures between 15 and 60 degrees F are considered energy neutral for horses. This means that within that temperature range, horses don’t require extra energy or calories to stay warm or cool. However, this assumes that the wind is not blowing and the horse’s hair coat is not wet, because both conditions increase the horse’s caloric needs

Horses instinctively know when they need extra calories to increase body temperature and maintain weight. Unfortunately, most horses are on a fixed diet and when additional calories are required to keep them warm or to maintain body weight, they are at the mercy of their owner’s ability to adjust the feed ration.

When feeding horses in cold weather, it is important to know two things:

  1. Don’t be deceived by woolly winter hair coats that can make a horse look fat. During cold weather, horses that are not receiving adequate rations first burn stored fat and then protein from muscle tissue to fuel daily activities. Initially, fat reserves stored along the ribs, crest of the neck and rump are used. Then the muscles in the neck, shoulder and hindquarters are sacrificed. So when trying to assess body condition on a winter-coated horse, run your hands over the horse’s back, hips and ribs to determine if he is losing weight. If you are uncomfortable estimating weight loss through palpation, use a weight tape to check the horse’s weight in the late fall and then weekly throughout the winter.
  2. Keep in mind that hay – not grain – is the best feed to help a horse generate body heat. The heat of digestion from five pounds of extra hay will raise the average horse’s core body temperature 1.2 degrees for nearly four hours. Forage is digested in the horse’s large intestine through bacterial fermentation, which not only provides nutrients but also generates heat. Concentrates such as corn and barley are low in fiber and are digested in the small intestine through enzyme activity, producing little heat.

Is your horse’s health important to you? AQHA’s “Your Horse’s Health” DVD gives trusted and practical advice on how to keep your horse at his best.

Winter Goals

When it’s cold, focus on providing plenty of long-stemmed hay, preferably free choice. Unlike grains, additional hay can quickly be added to a horse’s diet without risk of colic or founder.

When faced with cold weather, many horse owners tend to keep their horses’ hay intake constant while increasing the grain portion of the diet. Although grains are very calorie dense (a pound of corn contains 1,800 calories; a pound of oats contain 1,500) and work well to fatten a horse, they are low in fiber and generate little heat. However, additional grain provided in the fall will add a layer of fat that serves to insulate the horse and does help him retain heat.


Good-quality hay should be the foundation of any equine diet and the first component to be increased to generate heat or regain body condition. If a horse continues to lose weight on hay, add grain to increase the caloric supply. Remember that the sudden addition or increase of grain in a horse’s diet – especially of corn or barley – can cause colic or founder, so add grain slowly over several days.

Winter isn’t the only time of year your horse needs to be fed carefully. Learn more about your horse’s dietary needs and other important facts about your horse’s health from AQHA’s “Your Horse’s Health” DVD.

An idle horse in comfortable weather will consume roughly 3 percent of his body weight in feed every day and at least half of that should be forage.

Toward winter’s end, give your horses a thorough going-over to make sure that the cold winter months have not taken a toll on body condition. Pay particular attention to very old or young horses.

For more information on keeping your horse healthy, consult an American Association of Equine Practitioners member veterinarian in your area. For a list of members, log onto, or call 1-800-GETADVM

24 thoughts on “Winter Weight Loss”

  1. OK, everybody is worried about their horses losing weight in winter, but how do I keep my horses from getting too fat in winter? They get plenty of hay & VERY little grain (just enough to add a vitamin/mineral supplement…….& they just keep packing on the weight even when it is -40…….

    I don’t have an indoor arena, and the footing is rarely safe to work a horse…….

  2. Joanne, I had the same problem with horses becoming overweight during the winter. I feed round bales and was giving them free access to it. Since I do not live on the premises I could not control the amount of time they spent on the round bale. This year I added an electromagnet to the gate that gives them access to the round bale. The electromagnet is controlled by a simple timer like you would put on a lamp. This way, I can determine when they have access to the hay. In the morning, they come into the barn for their grain and I close the gate. During real cold weather I let them access the hay 24 hours. This seems to have solved my problem.

  3. We have a similar issue with some additional challenges. Four geldings age 14-35 live together out 24/7 in southern Michigan. They have an excellent shelter, heated fresh water and 2 hay feeders for grass/alfalfa mix hay. They come in 2Xday for feed. Ancient one gets 3lbs(4if he’ll eat it)warm soaked senior. He went off feed for several weeks while starting pergolide for cushings and lost 100 precious lbs. Now eating again and a little wgt coming on: when I can he gets in midday for soaked hay cubes. Next oldest, 26, is very overwgt also starting pergolide, hardly missed a bite. He and other 2 get a token handful of sr for supplements, vit/min and selenium. He has had some soundness so not ridden all year, but is 1 of 2 most active horses in pasture. Other 2 in good wgt and are (on vacation for the winter) trail horses. It’s just hard to keep the 2 old ones in healthy wgt. Ancient one does real well when pasture is active, 26 yr old will have to be muzzled this spring, poor guy.

  4. We could never have our horses on free choice hay. Even though you mention that there is no risk of founder, my mare started to be tender footed, as I was feeding more and more as it got colder. My vet told me that I just “cought in on time”, before she foundered. I increase or decrease the amount of hay I feed every day with the changing temperatures. And they only get 2 lbs of pellets per day.

  5. The article states ‘five pounds of extra hay’ and other articles say free choice. However they fail to mention that yes, some horses can founder easily on extra hay especially if it is alfalfa. They would be wise to mention that and state that extra or free choice hay should be grass hay to be safer. And you still need to moniter their weight. I worked at a barn where free choice or xtra alfalfa caused many problems.

  6. My old gelding (23 yrs old) started losing weight and we could see his ribs. We increased his grass hay (no alfalfa) and all he got then was a hay belly but we could still see the ribs. Our vet said to avoid the chance of his getting Ulcers to eliminate all grain (we were giving him 2 Cups of equine senior once/day as a supplement). He recommended Purina’s Wellsolve L/S (pelleted with NO grain). We’ve been giving him 4 Cups/day along with 2 C of rice brain and he’s filled out all over but does not have the hay belly. He looks like his old self and is more energetic. Living in Northern Nevada we have cold winters. At evening feed we give a sprinkling of alfalfa (not even a quarter of a flake)on top of the grass to help generate heat during the night (he has a stall to come into).Even tho we have the barn, when the temp gets down to below 20 degrees, we blanket him. Hope this info helps those who may have the same problem with their older guys.

  7. I am by no means an expert, but the expert from UT that spoke to our 4-H group said that in the winter horses need more hay, but not better quality hay. He said many horse owners feed the best hay they can, which is high in protein, etc., when they should instead feed more hay that is of less quality. Not moldy, or gross, but longer stem, maybe try “cow hay” instead of “horse hay” for your easy keepers. Wish I had your problem!!

  8. I have a 16 yr old aqha mare and I cant seem to keep her ribs and backbone from showing. I feed her a grain which a older horse mixture you get from the local MFA, and she gets plenty of hay. I have wormed her, but still no results. Any suggestions?

  9. Hi Dawn,

    Here is a suggestion offered by Dr. Lenz in The Journal…

    “Another good way to provide calories to a horse quickly and safely is to add fat in the form of corn oil to the diet. A pound of corn oil (two cups) contains around 4,000 calories compared to 1,800 for a pound of corn. Up to a cup of corn oil twice daily can be provided and should be mixed with sufficient grain to keep the mixture palatable to the horse. Four pounds of dry grain per cup of oil works well.”

  10. I have a bunch of old guys too and it is an on going battle to keep them where we think they should be for weight….I have tried everything.. Right now we are using omeg 3 powder Boss.. Black oil sunflower seeds… they contain about 2000 calories for a cup…wieght builder. optitizme…..And they get the oppropriate grain….for what they are old young mare brood mare ect….They also get beet pulp…and we feed soyameal..too….and alfaha cubes…All of that seems to be somewhat helpful…..our one girl had an abbcess so she lost lots of weight.. but is now on the road to packing it back on….my older guys… its just going to take time…..they dont fight back in the paddock so they are all feed seperate…..Can we say high maintance…We just added the sunflower seeds. so we will see how that helps….the one horse if i dont keep him on the soya meal he looses… he gets he gains .. so i have no idea
    I will try what ever to keep them looking good… Oh yeah And dont forget the oil and vinegar……That seems to work so far… nothing is going to gain over night just be determined….But i know what you mean its a struggle…Just cause a horse shows ribs doesnt mean they are not being fed ….keep an open mind.dont jump to conclusions..

  11. Dawn….

    I have a 10 year old mare that I’ve had the same problem with. I struggled for over a year trying to get her on the right diet and couldn’t get her to gain a pound until I met up with an equine nutritionist at the feed store. I told her I was afraid of founder because we had already had a scare with that. She suggested purina’s ultium. She told me it’s an all around food. Hope this helps!

  12. i have a 30 yr old horse,can not get weight on him, he will look very well then he falls away again,tryed beet pulp ,oil and i need to no whats next to try ,and how to start him out on something new to eat ,thanks

  13. I have a 10 yr old gelding who never raises his head – eats all the time. Large bales all winter and grass all summer. I can half way keep his weight under control in the summer because I ride alot, but when the weather turns bad it’s a free for all for his eating. I have a round pen that I’ve been thinking about using to monitor his eating habits. How many hours a day can I safely leave him in there without food to try and control his weight. Of course, he would always have water.

  14. We only give our horses 1/2 scoop of sweet feed or oats depending on the time of year and open feeding to hay. The hay is a mixture of alphalfa, timothy, and brome. According to the shoer are horses are overweight. Horses will eat all the time if you let them. You can cut the gain with supplements in the winter but allow them to have as much hay in the day and not at night that should help if you want to keep the weight down. We do not worry about the weight only because the horses are not ridden. I think most people give to much gain or pellets.

  15. I disagree with the article’s statement that hay can be increased quickly without risk. As a vet tech, I’ve seen lots of cases of colic, including some severe impactions, brought on by sudden onset of cold weather and sudden feeding of increased or free-choice hay. Reduced water consumption also plays a part – horses must drink enough water to make up for all that dry hay. I recommend increasing hay gradually, just like any other feed. Bucket warmers also help – the horse should never not have water available.

  16. hi my 16 year old qurter horse gelding always overweight has lost so much weight his winter his ribs are showing he has has 6 flakes of good hay plua a small 2 scoops of mentor live in ontario he is blanketed only out 4 hours per day now hay increased grain increased with vegetable oil shoul i call the vet

  17. i have a 4 year old filly
    that i can not put weight on
    she pot gut in summer
    looses it in winter
    she has not grown
    sence she was a year old help

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