We’ve become so accustomed to seeing shiny, sleek-coated horses with lots of extra flesh that we easily forget they’re actually fat. Some people actually use the phrase, ”well conditioned,” a term that should be reserved for fit athletes. Round ponies are called ”cute,” rather than ”chubby.” Carrying extra weight around is no healthier or desirable for horses than it is for us. But, even if you recognize your horse needs to lose weight, you may be unsure how to go about it without starving or depriving your horse. Stop worrying. Trimming down your horse doesn’t have to stressful on either one of you.
Many horses are overweight simply because they are being fed too many calories. The major offender here is grain. Horses love grain, like people love ice cream and fast food, but that doesn’t mean it’s good for them. Horses should be fed grain only when they’re unable to maintain a normal weight on hay and grass. Despite this fact, it’s difficult to find a horse that isn’t receiving some type of grain.
Feeding grain is reinforced by advertising that leads owners to believe they have to feed grains to get necessary vitamins and minerals into the horse. The combination of that warm, fuzzy feeling that comes from seeing your horse obviously enjoy what he’s eating, and rationalizing doing it so the horse gets things that he actually needs to get, is a powerful one.
Yes, It’s Calories
The first step in designing a weight-loss program is to figure out why your horse is overweight in the first place. This begins with a look at calorie intake. A rule of thumb is that a horse in light work needs the calorie equivalent of about 2% of his body weight in hay to keep a normal weight. For a 1,000-pound horse, this works out to 20 lbs. of hay. Admittedly, some horses will need a bit more, some a bit less, but this gives you a starting point.
The calories in hay are expressed as DE (digestible energy) and given as Mcal/lb. (megacalories/lb.). Hays actually vary widely in their calorie content, from 0.7 Mcal/lb. or less for poor-quality hays, to over 1.0 Mcal/lb. Most decent-quality hays are between 0.8 and 0.9, so we will use a figure of 0.85 Mcal/lb. to illustrate calorie intakes. That 20 lbs. of hay is providing the horse with 17 Mcal of energy.
There’s a big difference between hays and grains. Plain grains have twice as high a digestible energy (DE) as hay. Commercial feeds, because of the added fat and molasses, are often three times as calorie dense as hay. If you substitute 5 pounds of commercial grain mix, usually the minimum recommended on the bag, for 5 pounds of hay, the horse is getting a hefty increase in calories:
• 12 lbs. of hay x 0.85 Mcal/lb. = 17 Mcal/day
vs.:
• 15 lbs. of hay x 0.85 Mcal/lb. = 12.75 Mcal/day
PLUS
• 5 lbs. of grain x 2.55 Mcal/lb. = 12.75 Mcal/day
TOTAL 25.5 Mcal/day
To keep the calorie intake of a horse fed 5 lbs. of commercial grain a day the same as a horse fed hay only at 2% of his body weight, you would only be able to give him 5 lbs. of hay/day! That’s way too little hay for his digestive health.
The other major offender in terms of weight gain is insufficient exercise. Horses in paddocks or fields get more exercise than those in stalls, but it’s no substitute for the 20 or more miles a day a wild horse would wander to find sufficient food (likely of much lower calorie density). And it doesn’t compare to a regular, formal exercise program that keeps the horse moving at a rate appropriate for his fitness level for at least 30 minutes/day.
Exercise changes how the horse’s body uses its calories. Most calories are used by your horse’s muscles. Moving muscles burn more than resting muscles, but it goes beyond that. Exercise also improves the ability of the muscle cell to burn fuels and directs calories away from fat and into the muscle both as fuel and to be stored. The body contour changes that go with exercise aren’t just from less fat, but also larger, healthier, better functioning muscles.
Set A Goal
Our tables give you the average daily calorie requirements for an 1,100 lb. horse under various conditions and list the calorie content of various types of feeds. Your first step is to determine your horse’s ideal body weight. If you’re not sure about what it should be, ask your veterinarian for an estimate. Next, do a rough calculation of how many calories your horse is getting compared to his needs. If you’re feeding too high a calorie level (and most folks are), simply cutting back to providing what your horse would need to maintain his ideal weight should solve the problem.
For Example
Let’s say that Mary’s horse, Sonic, was being trail ridden for an hour four days a week and longed 20 to 30 minutes another two days. Trail rides were mostly trotting. Sonic’s work level is moderate. Mary hurts her ankle, can’t ride, and in four to six weeks Sonic’s weight has jumped quite a bit.
When she was working him, Sonic was getting 2.5 lbs. of a commercial grain morning and night, and about 15 lbs. of hay. Sonic’s working weight, before the gain, was about 1,050 to 1,100 lbs. A quick calorie check shows that was just about right for a horse his size in moderate work, but too much for maintenance. In fact, he was getting enough calories to support a weight of over 1,600 lbs. at maintenance.
There are two simple solutions here. If Mary doesn’t want to change his feeding routine, she can substitute 4 to 5 lbs. of a complete feed for her grain mix and add a suitable mineral supplement to make up the difference in mineral levels between the complete feed and the fortified grain. Or, she could also stop the grain and actually feed him more hay than she’s doing now, which is a big help with boredom, and give him all the minerals he needs from a mineral supplement, mixed into a small amount of soaked beet pulp (soaked has only ?? the calories of dry beet pulp) and a few ounces of flax for essential fatty acids. Note that neither one of these approaches involves feeding Sonic less food — just a change in the type of food.
If we take the same scenario as above, but find that Mary is now ready to start riding again, Sonic will lose the extra weight once he gets back up to his former level of exercise, so there’s really no pressing reason to do anything about it, although if he finds it more difficult to work with the extra weight (more huffing and puffing, legs filling), it’s smarter to cut back a bit on the grain until he’s back to full work.
It’s Not Starvation
One of the most common mistakes made with overweight horses is to cut their food intake drastically. Not only does this deprive them of the protein, vitamin and minerals they need, it causes metabolic shifts in the body that actually make the horse even more efficient at storing calories rather than burning them. For example, thyroid hormone levels drop and insulin resistance is induced.
Drastic cuts in calories may also trig ger the potentially life-threatening condition hyperlipidemia, in which huge amounts of fat are released into the blood stream. This can be severe enough that a blood sample actually looks white. Ponies, miniature horses, donkeys and mini-donkeys are at greatest risk, as are horses with Cushing’s disease or severe and uncontrolled insulin resistance.
Instead, feed the horse what he needs to maintain a healthy body weight and, eventually, that’s what he’ll have. A good starting point is between 1.5 and 2% of the ideal body weight if the horse is getting some regular exercise, or 1 to 1.5% of ideal body weight if the horse is not regularly exercised. If this ends up being a greater than 25% reduction in calories over the current intake, go with the higher number, the 25% reduction, until the horse has lost some weight.
For Example
Peppermint Twist is an ”only horse,” 14.3-hand Morgan mare with a body condition score of 8+ and weighs in at 1,200 pounds when she should weigh about 800. She’s out on grass a high-quality pasture (clover and mixed grasses, not overgrazed) for 12 hours a day, fed 15 pounds/day of early cutting hay from the same pasture and three lbs. per day (weight before soaking) of a 50:50 mixture of wheat bran and beet pulp. She gets no formal exercise at all since her owner went to college. This was the same diet Peppermint had when she was eventing.
Because of the early cutting of her hay, it probably has a higher than average DE. Assuming a DE of 1 Mcal/lb. from the hay, for a total of 15 Mcal for the day, and another 3.6 DE from the beet pulp and bran, Peppermint Twist was getting 18.6 Mcal for these sources alone. Her maintenance need is about 12.8. But, even at that, for her to be as heavy as she is, she must be taking in quite a lot of grass when on the pasture. This is what many people forget to factor into their calculations.
A completely sealed grazing muzzle is the first stop for her weight-loss plan, since it’s impossible to know, or control, how much she is eating on pasture and the pasture is energy dense. If the owner drops the amount of hay, beet pulp and bran down to a total of 12.8 Mcal, that alone will over a 25% drop. If this is combined with not allowing grass it would be a drastic calorie cut, which we don’t want to do.
The plan devised for Peppermint was to:
• Divide turnout into one four-hour turnout during the day, and an eight-hour turnout at night, always with a sealed grazing muzzle.
• Keep her on a dry lot the rest of the time and feed a 25% reduction in calories, which would be 13.6 Mcal, which she can get from 12 lbs. of hay and a pound of beet pulp with 6 oz. of flax, used as a carrier for her minerals.
• Once she gets down around 900 lbs., can shave her calories down to the 12.8 Mcal she should need to hold a normal weight of 800 lbs. by giving 12 lbs./day of her hay, with a total of 0.5 lbs. of beet pulp and 3.5 oz. of flax, divided twice a day.
Bottom Line
The most important thing is to add exercise or increase the amount the horse is already doing. Turn out does not count as exercise. Aim to get the horse moving for a minimum of 30 minutes a day, no breaks, no stops to enjoy the scenery or chat, definitely no munching along the way.
If the horse is unfit and heavy, walking may be all that he can handle at the start. Shoot for a pulse of between 80 and 100 beats per minute during the exercise. Make sure the horse’s feet are correctly trimmed and balanced (he’s putting a lot of weight on those feet!), and keep a close eye on the legs for any filling or heat as you go along. You can hand walk, longe, pony from another horse or ride. Just get him moving!
