Feeding from foaling to weaning and beyond

Remember the children’s fable about the tortoise and the hare? The hare took for granted that he’d win the race handily because of his speed. He took a nap instead, and the plodding tortoise passed him as the undisputed winner. The moral of the story: Slow and steady wins the race.

The same is true for growth in young horses. A horse that grows too quickly can be at greater risk of developing joint and bone diseases. One that grows too slowly might be stunted. A carefully designed feeding program supports a young horse’s growth at a moderate, even pace so he can reach his full potential.

“As nutritionists and managers, we should identify times when growth gets uneven, slow, or rapid and then try to even that out through a feeding program,” says Laurie Lawrence, PhD, a professor in the University of Kentucky’s College of Agriculture, Food and Environment, in Lexington.

Conversations around young horses’ growth often center on height. The young horse’s weight, however, is just as important. A growing foal that gets too fat can be predisposed to developmental orthopedic diseases such as osteochondritis dissecans (OCD, loose cartilage and/or bone fragments in the joints), says Kentucky Equine Research (KER) Australia equine nutritionist Clarissa Brown-Douglas, PhD.

“Owners should regularly weigh and body condition score their growing horses and adjust calorie intake to ensure they maintain a steady growth rate and remain between a 4 and 5 on the Henneke 1-to-9 body condition score scale,” she says, with 1 considered emaciated and 9 considered obese.

A well-planned feeding program helps a foal’s caretakers manage growth rate effectively. While we might know the fundamentals of what nutrients and minerals horses need for healthy development, there’s no one-size-fits-all feeding regimen for all foals. In this article Brown-Douglas and Lawrence highlight common foal-feeding challenges and solutions and address the roles of forage and supplements.

Foaling to 3 Months

A newborn foal’s primary nutrient source is his dam’s milk. Immediately following birth the colostrum, or first milk, provides needed antibodies to protect the foal from disease-causing microorganisms. 

“Colostrum is also high in fat, so it is an important calorie source,” says Lawrence. “Milk itself is a highly available source of essential amino acids (which must be provided in the diet because the horse’s body can’t produce them), as well as calcium and phosphorus.”

A mare consuming a balanced diet, including plenty of quality forage to meet her increased energy and nutrient requirements during lactation, is likely producing adequate milk, says Brown-Douglas.

“In some cases foals may not receive adequate milk, either through poor supply or in the case of orphan foals,” she says. “For these youngsters there are great milk substitutes on the market, and a balanced creep feed can be offered from around 2 months of age.”

She and her colleagues recommend offering these foals no more than 2 quarts of milk replacer at one time. Results from KER studies have shown that foals fed 2 quarts of milk replacer six times per day gained less weight than foals in a control group that received adequate milk from their dams during their first month. Their height gains, however, were similar.

When choosing a milk substitute, look for products that have been formulated to mimic the nutrient composition of mare’s milk with additional trace minerals and vitamins. And, indeed, the key to successful milk-substitute feeding is to offer small amounts often—mimicking natural nursing patterns—so as not to upset the foal’s sensitive digestive tract.

“To effectively feed young orphan foals so that growth and gastrointestinal health remain normal is a fairly labor-intensive job,” Lawrence says. “Allowing the foal to nurse the mare until it’s a few months old is much more desirable, making a nurse mare a good idea for orphans.”

While a foal is still nursing, be it from his dam or a nurse mare, he will also begin nibbling on forage and eating out of the mare’s feed tub. These are natural and acceptable behaviors. For most young horses you don’t need to introduce additional feed at this stage.

A mare’s milk production peaks about two months after foaling. After this, Brown-Douglas says, milk begins to play less of a role in the foal’s diet. This is an ideal time to begin introducing a feed formulated for growing horses. Such feeds contain the correct balance of amino acids, vitamins, and minerals for growth. Feeding it in a separate tub introduces the foal to eating on his own, which will prepare him for weaning.

Weaning Time

Weaning might occur as early as 3 months of age for some foals, or not until 6 months or later for others, depending on a farm’s management practices. Foals can be weaned at a very early age but will need alternate nutrient sources. On average, most foals still receive 30-50% of their required nutrients from milk at 4 months of age, Lawrence says, though by then they are accustomed to eating solid foods.

“At weaning, the manager will have to consider the amount of solid food the foal has been eating and how much will now be needed to substitute for the milk,” Law­rence says. “Many foals will go through a growth slump after weaning that is then followed by a period of rapid growth.”

Ideally, you want to modify the feeding program prior to weaning so the young horse is already used to eating his own forage and some concentrate. This will help avoid a big slump and a big rebound. When deciding how much concentrate to feed, Lawrence uses recommendations she received from the late Edgar Ott, PhD, who was a respected equine nutri­tionist at the University of Florida.

“He told me a long time ago that a good rule of thumb was 0.5 to 1.5 pounds of concentrate daily per month of age for a typical Thoroughbred foal or weanling,” she says. “At 6 months of age, that would be a range of 3 to 9 pounds per day.”

You need to consider several factors, however, before scooping out pounds of feed: forage quality, the foal’s body condi­tion, and environmental conditions.

For example, Lawrence says winter can be as demanding on a young horse as weaning. Growing horses housed outside in cold climates use calories to stay warm, which often causes growth rates to slow. Then in the spring, mild climates and abundant forage can fuel rapid growth.

Avoiding Joint Disease

While some career-ending joint condi­tions have a genetic component, others don’t and can be prevented with correct nutrition during development and growth. Ideally, the broodmare should consume a balanced diet leading up to, and during, her pregnancy, Brown-Douglas says.

“Mare’s milk is low in trace minerals, so is imperative that trace mineral intake, especially copper and zinc, is adequate during the last trimester of pregnancy,” she says. “This provides the growing foal with mineral stores for cartilage develop­ment after it is born.”

As important as adequate and bal­anced nutrient intake is to warding off joint disease, so too is appropriate body weight, says Brown-Douglas. Growing horses should be maintained at a body condition score between 4 and 5, she says. For horses that tend to gain weight easily, caretakers might feed a low-intake bal­ancer pellet, which will ensure the young­sters receive proper nutrients for growth without consuming too many calories.

“The source of calories in the young horse’s diet has also been linked to joint disease,” Brown-Douglas says. “Research has shown that horses grown on high-sugar and -starch diets (high-grain) have a greater incidence of OCD than horses grown on diets based on fiber and fats as calorie sources.”

Although less common than joint conditions, deficiencies in nutrients such as protein, calcium, copper, and zinc can affect muscle, skin, or other tissues.

Focus on Forage

In nature forage would be available at birth. It is the cornerstone of equine nutrition, not only as a nutrient source but also support for digestive health, so horses of any age should have access to forage, such as hay, around the clock, says Brown-Douglas.

“Foals will nibble at hay and pasture from a very young age,” she says. “Many breeders will offer their young, growing horses higher-protein forages such as al­falfa to provide increased levels of amino acids in the diet.”

Brown-Douglas recommends testing the nutrient content of pasture and hay.

“It is important to have both tested so that we know what we are working with and can design a feeding program that fills in any gaps and takes into account the young horse’s calorie intake,” she says.

Many owners focus on concentrates and supplements without realizing how many nutrients forage alone can provide. Well-managed pastures in Central Ken­tucky, for instance, can contain 15-20% crude protein on a dry matter basis in the spring and fall, Lawrence says. This is es­sentially the same protein concentration found in alfalfa hay.

“On the other hand, when foals are not growing fast enough or appear skinny, people often look only at the concentrate without considering whether the problem could be the forage quality or quantity,” she says. “Before adjusting concentrate amounts upward to induce fast growth, it is good to look at the forage and, if pos­sible, improve forage quality or quantity.”

If the forage quality is low and pro­vides less protein and fewer calories, the youngster needs higher concentrate amounts. It’s also important to consider the weanling’s living conditions. Those spending the winter outdoors in Minne­sota versus those wintering in Florida will need different amounts of concentrate to supplement their forage.

“Managers will even out the slow growth with good-quality forage and concentrate in the winter and then often reduce concentrate in the spring if there is abundant pasture,” Lawrence says. “The goal is to balance the feeds and use nutrition as a management tool for moderate, even growth.”

Putting it All Together

Designing a feeding program for a young horse starts by evaluating his forage. A horse receiving a timothy hay that is low in calories, protein, and minerals might need more concentrate than one receiving good-quality alfalfa-orchardgrass mix or grazing high-quality pasture. Even young horses on good forage with adequate protein and calories likely still need a feed or supplement fortified with additional vitamins and minerals for growth, says Brown-Douglas.

A common misperception Brown-Douglas encounters is the role of protein in a young horse’s diet. In the past, researchers believed feeding too much protein led to joint diseases, such as OCD, in young horses.

“This has been disproven, and protein (especially its building blocks, the limiting amino acids lysine, methionine, and threonine) are very important for correct growth,” she says. “It is, in fact, excess energy intake and rapid weight gain which can negatively affect joint health, so in rapidly growing youngsters, a high-protein but low-calorie balanced vitamin and mineral supplement is recommended.”

A commercially manufactured concentrate intended for growing horses and fed at appropriate rates with good-quality forage should meet nutrient needs, Lawrence says. But it’s always good to have a salt block available, especially in hot weather.

As for other supplements, Brown- Douglas and Lawrence agree that while some foals receive probiotics to manage gastrointestinal health, the results of studies on these products (in horses of any age) have been inconsistent.

“The efficacy of probiotics in horses is questionable due to the acidic nature of the stomach and small intestine, which the probiotics must pass through before entering the hindgut,” Brown-Douglas says. “In cases where horses are scouring (have diarrhea) or have serious hindgut issues, a probiotic may be suggested, but it is one of those supplements in the ‘might not help, can’t hurt’ category.”

She says the most common question she gets from owners of youngsters is what to feed to make a horse grow taller.

“Horses can be fed to achieve their optimal genetic height, but as yet we have not discovered the magic nutrient to make them grow taller than what they were genetically predisposed to be,” she says.

Above all else, both sources agree that owners should design well-balanced feeding programs for developing horses based on the individual. It can be tempting to use a one-size-fits-all approach, especially for young horses living in a herd, but that might not provide adequate nutrients to meet each one’s long-term needs.