The primary reason I started “Jim the Feed Guy” is that in every horse group I was a member of there were many people asking for help to add weight to a “hard keeper”. In less than ten minutes there were 326 comments all advocating throwing more fat and calories at the horse. Dozens of people proclaiming “miracles” seen from their favorite fat supplement and all of this before asking a single question about the horse like age, condition, workload, etc.

The single largest class of horse I’m asked to help with are “hard keepers”. Personally, I will trade my “easy keepers” for “hard keepers” any day because it’s much easier to maintain weight on a horse than to lose weight when it is done properly.

I have three typical AQH mares that I struggle with to keep at a lower healthy weight. My other horse is an OTTB that is easy to maintain weight.

There Are No Hard Keepers Only Broken Horses

Let’s get this out of the way up front. There are no “hard keepers”. The NRC puts the daily caloric requirement for an average 1,100 pound horse in little or no work at around 14,000 per day. If that horse is eating 20 pounds of quality grass hay at 800 calories per pound they should easily maintain their weight providing everything is working properly.

Before everyone gets hysterical, all horses are individuals and certain breeds absolutely trend to the heavier side or lighter side. There is no question that the average thoroughbred is going to require more calories to maintain weight than the average Quarter Horse. Flair the Mare easily maintains weight on 20 pounds of orchard grass hay daily while Raven the OTTB needs a few pounds of concentrated feed to maintain her 6 BCS.

The problem is that typically when I am called in to help with a hard keeper they are being stuffed with 30,000 to 40,000 calories per day between high octane feed, fat supplements and oil. Given that the average horse requires 14,000 calories per day to maintain weight BUT an individual like Raven requires 16,000 calories per day to maintain weight I don’t see that as a problem. However, when a horse is getting three to four times the calories required and still not gaining or maintaining weight THE HORSE IS BROKEN and needs to be fixed before you make things worse.

It All Starts With the Teeth

Nature designed horses to eat grass and other plant material in order to thrive. No equine diet will work unless the proper amount of fiber is introduced into the hindgut of the animal and best source of this fiber is high quality forage from pasture or hay.

In order to maintain weight horses must process forage which can’t be processed if it hasn’t been properly chewed. Without healthy bearing surfaces the horse is unable to grind forage finely enough to be processed by the 120 feet of equine digestive system behind them.

When dealing with a new horse, particularly a rescue, it is essential to get a qualified equine dentist in to float teeth. If you have rescued a malnourished horse with a questionable background it’s teeth need to be cared for and it will probably require a couple of sessions to get them right. The dentist is the last specialist called when money runs tight.

Sometimes the dentition of the animal is too far gone to ever support properly grinding forage and we must look to forage replacements in the form of soaked cubes or pellets.

When we have a good assessment of dentition we know how to proceed with forage selection.

Fecal Samples

A heavy parasite load will have a debilitating effect on weight gain and general health of the horse. If you haven’t had a fecal exam in the last three months it’s time for another check.

Don’t just hit the horse with wormer and hope for the best. We are already dealing with “wonder worms” that are resistant to medication, please don’t contribute to the problem. If it’s determined that there is a high parasite load then treat accordingly.

Look to the Gut

The last and most important block to check is the entire digestive system which may not be as hard as it sounds since the whole thing is pretty simple if we don’t complicate it.

The horse has evolved to process grass as it’s primary source of energy and it’s a terrible energy source so it requires 120 feet of digestive tract to extract the energy required to sustain a horse.

I’ll save the details of the digestive system for other posts but for now we’ll focus on the hindgut which is where all the weight gain happens in horses and the biggest reason most horses won’t gain weight.

Digestion in most animals involves bugs of some kind to help breakdown the material that is consumed. In herbivores like the horse the microbes are critical to proper processing of forage.

This explanation is really oversimplified so for all you eq sciences majors out there I’ll beg your forgiveness.

The forage is softened up by the acid in the stomach before it passes through the small intestine where starch, sugar, proteins and other essential nutrients are processed and absorbed. Fiber, which is the biggest part of forage by volume is sent to the hindgut where it is dumped into the cecum which is a big fermentation vat. If anyone has made wine at home from a kit the cecum works almost exactly the way the fermentation bucket works. Plant material goes in, the bugs eat it and poop out bioavailable nutrients for our horse.

The biggest byproduct of this process are volatile fatty acids. VFAs are the best source of fat and subsequent weight gain for a horse because that’s how it works in their natural environment.

When the hindgut is broken this process doesn’t happen efficiently and our horses don’t thrive. So what breaks the hindgut and how do we fix it?

Sugar and Starch Are the Enemy

If the microbial colonies in the cecum aren’t healthy then there aren’t enough bugs to process the fiber. These microbes are happiest in a low acid environment so once the acid level in the hindgut increases the bugs begin to die. The primary reason for an increase in hindgut acidity is starch and sugar.

The primary source for the starch and sugar overload is concentrated feeds and whole grains. This is the reason the worst thing for an underweight horse is to load it up with large, high calorie, high starch meals. Doing this sets up a cascade of events that end in disaster and in some extreme cases death.

Most people think that OTTBs are ulcer ridden messes because of the stress they are under but the reality is they are stressed by the ulcers and the ulcers are caused by the high starch low forage diets they are on to get the greatest amount of speed from them.

Recent studies show that feeding one pound of NSC per meal will increase the risk of moderate to severe equine gut ulcers by 260%! Most sweet feed and racing formulas are at least 50% NSC so a meal of two pounds is all it takes to create havoc in the horse’s gut. That’s not a very large portion for these horses so when a TB pounds down six pounds of a race formula feed severe ulcers are inevitable.

Large Meals Will Work Against You

It’s instinctive, if it’s skinny feed it! But for our friend the enigmatic horse this philosophy will backfire on you.

As stated above, high volumes of starch will imbalance the hindgut and kill the good fermentation bugs. But that’s not the only consequence of large concentrated meals.

The horse’s digestive system works on a 36 to 48 hour cycle in order to extract the maximum amount of nutrients from forage. Like a factory assembly line there’s only so much room on the conveyor belt so if we overload the filler chute the conveyor must move faster. We call this rate of passage and increasing the rate of passage decreases the amount of time food has available for processing.

When I finally get called in by a frustrated owner the answer to my query of the current feeding program is invariably some version of:

5 pounds of Ultium Competition, 1 pound of Amplify fat supplement, 2 pounds of alfalfa pellets and a cup of rice bran three times a day. That’s 24 pounds of concentrated feed and fat for a horse that should be getting 24 pounds of grass hay. Except “he hates hay, he won’t touch it”.

Of course he’s not going to eat his hay, would you eat your broccoli if you just ate three pizzas?

Fixing the Gut

The first priority is to rebuild the microbial colonies in the cecum and the only way to do that is to neutralize the acid in the system. The best way to begin this process is with forage so it’s imperative to get the teeth in shape as soon as possible.

Equine saliva is the best acid buffer available for them and they only produce saliva when they are chewing. This is why full time hay is so important to horse health.

If the horse is showing symptoms of severe ulcers consult with your vet on a course of action. If a horse isn’t thriving on triple the required calorie load my first guess would be ulcers although there may be other causative conditions. Your vet is the best source for any pharmacological treatments of acute conditions.

Move the horse to a low NSC feed and reduce the volume. We want to keep meals of concentrates to under three pounds. I know the rule of thumb is 5 pounds but I’d prefer some margin for error. Three meals of three pounds is fine. Keep the NSC of the feed under 20% and if it’s not listed on the tag as sugar and starch don’t use that feed. NSC is the value of sugar plus the value of starch.

Adding supplemental probiotics won’t hurt for an underweight horse but the best source of probiotics is forage so it is critical to get them eating as much hay as possible. Some alfalfa is helpful for calories, it’s tasty and the calcium helps to buffer acid.. Good, clean, soft grass hay is great too. These horses need hay in front of their faces at all times.

Introduce a good gut support supplement. My personal favorite is Purina Outlast, this all natural supplement has come through for me time after time.

If the hindgut is responding you should see an increase in hay consumption and a generally better attitude in two weeks or less. They bounce back fairly quickly.

If it’s a horse with poor dentition then you must introduce forage replacements that can be made into a mash. A complete senior feed will work well. Beet pulp is also a favorite of mine. Average protein, high fiber, low NSC is the prescription for a healthy hindgut and that’s beet pulp.

Fat is NOT the Answer

The traditional way of putting weight on a horse was to add fat to it’s diet. Sometimes it actually worked but there are consequences.

In recent years fat has become a good source of controlled energy for horses in certain disciplines that require a steady, regulated source of energy. When supplemental fat is delivered in a well balanced formula in a bioavailable form it fits that role well.

Throwing large quantities of high fat supplements at a horse without anything to balance it with is not the best way to put weight on a horse.

I’m cautious in my use of reference to wild horses because we ask our domesticated breeds to do so many different things but when it comes to digestive health and nutrition working with what nature gave us is the best way to go. Horses in the wild encounter many different sources of forage, some great some not so great. I can tell you one thing with absolute certainty and that is a wild horse has NEVER stumbled on a natural pool of canola oil or any rich source of plant based fat.

It’s because of this that evolution did not deem it necessary for a horse to have a gall bladder to provide a readily available source of bile to handle surges in fat intake. Horses secrete bile through ducts in the liver and don’t store any for “emergencies”.

Horses will adapt to increased fat in their diet but it requires a slow ramp up over ten to 12 weeks and it’s still not the best way to put weight on a skinny horse.

Fat can also mask an underlying problem. If you have a horse that requires a daily portion of a fat supplement to maintain weight there is something wrong.

The best way for horses to have a good, highly bioavailable fat source is to ensure that the system is working and the microbial colonies are breaking down quality amounts of fiber.

Will feeds with a higher fat content help? Yes, because of their formulation and the fact that many high fat feeds are also low NSC.

A Quick Review

So if your horse has been a traditionally hard keeper or if you’re just being introduced to a new horse or rescue here’s a quick checklist:

Vet Check
Dental Check
Parasites
Reduce Feed Volume
Increase Meals
Low Starch
Balance Gut
Forage, forage, forage.

Patience is key. Don’t look to achieve results overnight and fix the weight gain first. Worry about top line and muscle development later. If you try to build muscle while looking for weight gain you’ll be diverting resources.