How to Feed a Growing Foal: Nutrition from Birth to Yearling

Raising a healthy foal involves closely monitoring their growth. This will help you make appropriate changes to their diet and management to support optimal development.

Foals grow quickly in the first few months after birth, reaching ~80% of their mature height and ~43% of their mature weight by just six months of age. This rapid growth rate makes foals susceptible to developmental and joint issues, which can impact their future well-being and performance in the long-term. ^[1]

Throughout the first year of life, it is critical to meet your foal’s protein, vitamin, and mineral needs without exceeding calorie requirements. Over-feeding increases the risk of developmental orthopedic diseases (DODs).

In the first couple of months, the mare’s milk is usually sufficient to meet a foal’s energy and protein needs. Properly feeding the lactating mare will ensure she produces enough healthful milk for the foal. ^[2]

Although foals begin nibbling at feed and forages as early as one week old, they generally do not need to eat feed and forages until two or three months of age. After six months, your foal’s diet will largely consist of forages and concentrates to continue to support their growth. ^[2]

This article will discuss growth patterns in foals, creep feeding, how to adjust their diet as they grow from weanling to yearling, and nutritional requirements at different ages.

Foal Growth & Development

One of the most important factors to consider when feeding foals is their growth rate. Foals that are growing slowly may need more energy in the diet from higher quality hay or other energy-dense options, whereas fast-growing horses may need restricted access to feed.

Another reason to pay close attention to the foal’s growth over time is to support joint health. Fast growth has been linked to joint issues in growing horses and developmental orthopedic diseases (DODs) including physitis and Osteochondrosis dissecans (OCD). ^[1]

Factors Affecting Development

A foal’s potential mature body weight and conformation are largely determined by genetics or breed. ^[3][4]

How fast they develop and whether they develop to their genetic potential is affected by many factors, including nutrient availability, environmental factors, and management.

Nutrient Availability:

• Feeding program
• Month and season of birth
• Pasture quality and availability
• Gestational nutrition and health of the mare
• Colostrum and milk intake

Environmental and Management Factors:

• Freedom of movement and exercise level
• Ambient temperature
• Weaning and associated stress
• Health history
• Parasitism

Intro to Equine Nutrition

Gain a deeper understanding of your horse's nutrition needs. This free introductory course provides a foundation for horse owners to learn how to balance your horse's diet.

Enroll Now

Mare Nutrition

Horses evolved with seasonal estrus so that the end of gestation and beginning of lactation aligns with the presence of fast-growing, energy-dense spring grasses.

This helps ensure that mares are meeting their energy and protein needs when they are at their peak. The mare can produce large volumes of milk with abundant pasture, and the foal will have high-quality forage to graze. ^[5]

Weight gain is the fastest in early life. The mare’s nutrition largely impacts this period of growth during gestation and also affects the mare’s milk production. ^[5][6]

Measuring Foal Growth

To appropriately balance your foal’s diet, it is important to regularly measure and record their weight. Because large animal scales are not widely available, you can use a weight tape to measure their girth and apply the following calculation: ^[7]

The calculated value can be compared to estimates of their current weight, as shown in the table below.

Growth of a foal predicted to weigh 500 kg / 1,100 lb as an adult

The calculation used to provide the estimated weight is as follows, where M is the predicted mature body weight (kg) and A is age in months: ^[3]

Comparing your foal’s ideal weight to their actual weight as measured with a scale or weight tape can help you determine if your foal is on the right track. Ideally, measurements should be taken frequently to monitor their overall growth pattern rather than looking at a single measurement.

You can also calculate your foal’s average daily gain (kg) with the following equation, where M is the predicted mature body weight (kg) and A is your foal’s age in months: ^[3]

Growth Patterns

Foals will naturally go through periods of slower growth followed by growth spurts during the first 1.5 – 2 years of life.

Although fast growth may be desirable for getting a better price at sales, aiming for fast growth can be detrimental, particularly for joint and metabolic health. ^[1][8]

Slow Growth

Consult with your veterinarian and equine nutritionist if you observe long periods of slow growth. Slow growth may be due to the following:

• Genetic disorders
• Growth abnormalities
• Illness or injury
• Nutritional deficits
• Nutritional imbalances

Your veterinarian will also determine appropriate vaccination and deworming programs to help your foal avoid diseases caused by common pathogens.

Weight Gain

The season and month of the year when your foal is born significantly impact their growth rate. Studies in the Northern Hemisphere show that foals born in January have different growth patterns than those born in May. ^[5][9]

Daily weight gain is lowest in the first winter when more calories are burned to maintain body temperature.

Following this period of slow growth, most foals experience a growth spurt the next spring and summer. This is referred to as compensatory growth or catch-up growth.

Erratic growth patterns are possibly linked to DODs, and aiming for a smooth growth curve through the winter and spring is preferred. Your foal may require more feed through the winter and restricted pasture access in the spring to regulate growth. ^[5]

Height Gain

The foal experiences the fastest height gain in early life, and the growth rate decreases over time. For example, Thoroughbred foals have reached 80% of their adult height by six months. ^[1]

Breed Differences

Growth curves and the above growth calculations are based on observational studies that measure the growth of thousands of foals over time. To date, this research has mostly involved Thoroughbred foals. ^[5][10]

It is possible that large breeds, such as Percherons, have different growth patterns than smaller breeds, such as Arabians. However, current research on these breeds is inadequate to make firm conclusions. ^[5]

Instead of focusing on breed-specific growth patterns, it is best to consider the individual horse and how its growth is impacted by health, nutrition and environmental factors.

Newborn Foals

A newborn foal should be nursing on its dam within the first eight hours of life. This first milk is nutrient-dense colostrum, which contains antibodies to help build the foal’s immune system and protect against common pathogens.

This process of building the foal’s immunity is called passive transfer; antibodies are absorbed from colostrum through gaps in the intestinal wall that only exist for the first 24 – 48 hours of life. You can estimate the success of this transfer by an IgG test to measure how much antibody is present in the foal’s blood.

After colostrum, healthy foals will consume approximately 25% of their body weight in milk by two weeks of age. ^[11]

Foals may also start nibbling on feed, forages, and even manure as early as one week of age. ^[11] This behaviour helps establish their gut microbiome, which is critical for fermenting forages later in life.

Young foals are very susceptible to dehydration due to diarrhea or low milk intake. Contact your veterinarian immediately if you have any concerns about the newborn foal’s ability to suckle.

Conditions such as foal diarrhea, rotavirus, and pneumonia can quickly become fatal in young foals.

Introducing Feed

Two-month-old healthy foals drink 20% of their body weight in milk each day. ^[11] However, milk alone may not fully meet the foal’s nutritional requirements for growth. ^[2]

Depending on your foal’s growth, creep feeding can be introduced around 2 – 3 months of age. Foals might start to explore their mother’s feed in early life, but creep feeding refers to offering feed specifically for the foal.

Creep feeding can be accomplished by providing foals with feed in their own feeder or an isolated area. ^[2]

Selecting Creep Feeds

Creep feeds for pre-weaned foals should have sufficient protein, amino acids, and minerals to support their growth.

When reading the feed tag, look for foal feeds that have at least the following on an as-fed basis: ^[2]

• 14 – 16% crude protein
• 0.7% lysine
• 0.8% calcium
• 0.5% phosphorus

These feeds should contain highly digestible protein and energy sources such as soybean meal, alfalfa, oats and oils. Alternatively, you could provide these commodities on their own to carefully balance the diet.

A general guideline is to feed 0.5 kg / 1 lb of creep feed per month of age. ^[8] The amount can be adjusted to keep your foal at a body condition score of 5 out of 9 on the Henneke body condition scale.

Alternative to creep feeding

Creep feeding with a separate feeding arrangement for the foal may not always be possible. In addition, even when feeding a commercial foal feed at recommended amounts, there is no guarantee you will be meeting protein and mineral requirements of these rapidly growing foals.

To simplify their feeding programs, the mare and foal can be offered the same feed. The broodmare’s diet should be professionally formulated to the needs of early lactation. These are the same as the weanling foal’s requirements in terms of protein and minerals per Mcal of energy. Allow the foal to have free access to the mare’s feed.

As the foal drinks less milk, he will eat more of her diet and she will get less, naturally lowering her calories and decreasing milk production. If the mare starts to lose too much weight, increase all elements of the diet by 10%.

The advantage to using this method is that the foal will be fully accustomed to the diet at the stressful time of weaning. Your nutritionist can tell you how much to feed for the foal’s age and weight at weaning.

Pre-Weaning Diet

By six months, the mare’s milk production and the foal’s milk intake will be fairly low. Although the growth rate is slower than in early life, the foal’s nutritional requirements are higher.

Depending on when foals are born, this time will coincide with varying pasture quality. For example, foals born in January will be four to six months of age on abundant spring pasture. They will likely not need as much added hay or concentrates compared to foals at this age in the winter.

In preparation for weaning, continuing with creep feed or beginning feeding them the diet they will be on post-weaning can be beneficial. This will help the microbiome and digestive processes adapt to the post-weaning diet.

Creep feeding can also help your foal maintain their body condition through weaning, reduce the stress of weaning, minimize fluctuations in growth, and support bone development. ^[2]

Studies suggest feeding foals high fat and fibre feeds instead of starch and sugars contributes to lower stress at weaning. ^[12] However, this has to be weighed against the risk of lower bone mineral density in foals fed high fat and fibre. ^[25]

Pre-Weaning Diet of 6-Month-Old Foal

The following pre-weaning diet is based on a six-month-old foal with an estimated mature weight of 500 kg / 1,100 lb.

Feeding a Weanling (6 Months to 1 Year)

Weaning is a stressful time, which can contribute to loss of appetite, behaviours such as wood chewing and aggression, and a drop in body weight.

You can minimize weaning stress in your growing foal by: ^[32][33]

• Keeping the rest of the diet the same before and after weaning
• Weaning foals in groups outdoors, with a calm adult horse “babysitter”
• Allowing the foal to still see, smell and hear their mother when separated

Below are the key factors to consider when feeding a foal after weaning to support optimal health.

1) Choose High-Quality Forages

Foals can get most of their energy and protein needs met by consuming high-quality forages, including pasture. However, if weaning occurs in mid-summer or winter, pasture quality may be poor.

When choosing hay for weanlings, select high-quality hay that is harvested at an early stage of growth for maximal protein content.

Legume hays such as alfalfa are often recommended due to their high protein, energy, and calcium content. However, the high calcium content needs to be carefully balanced with a high phosphorus source like bran.

Look for soft, leafy hay indicating low-fibre and high-protein content.

While some visual cues provide an indication of forage quality, the only way to accurately assess the nutritional value of hay is to submit a sample for analysis. In addition to protein and fibre content, a forage analysis will also measure sugar, starch and mineral levels.

An equine nutritionist can help you interpret the results of your hay analysis so you can formulate a diet with proper levels of protein and minerals. A balanced diet will support optimal growth without providing unnecessary calories.

2) Avoid Excess Energy Intake

Depending on hay and pasture quality, your foal may not require additional energy sources. Fast growth and over-conditioning have been linked to DODs, so it is best to avoid excess energy intake. ^[1]

Osteochondrosis dissecans (OCD) lesions in the shoulder, stifle and tibiotarsal joints are more prevalent in horses with greater than average weight gain. ^[1]

Some horses may be genetically predisposed to OCD lesions and should be fed carefully to avoid rapid growth. Genetic studies suggest that anywhere between 2% to 46% of OCD can be explained by genetics. ^[13]

Larger horses, such as Hanoverian warmbloods and Holsteiners, appear to have the highest genetic risk for certain lesions, such as hock OCDs. ^[13]

For these breeds, avoiding periods of fast growth by carefully restricting caloric intake may help decrease the incidence of OCDs. Calorie restriction should be done while supplying adequate protein, vitamins and minerals to maintain the quality of growth. ^[5]

3) Add Calories from Moderate Sugar and Starch Sources

For growing horses who require additional energy beyond what is provided by forages, choose energy sources with easily fermentable fibre, and moderate rather than high levels of starch and sugars.

Sugars and starches, along with fructan, are also known as non-structural carbohydrates (NSCs), and they are found in high levels in cereal grains (oats, corn, wheat, rye, barley). High intake of NSCs may also be associated with an elevated risk of OCD.

Link between grain feeding and OCD

Heavy grain feeding and less exercise after weaning have been associated with higher prevalence of OCD, in some studies but not all. ^[14][15][29]

Feeding high levels of starch and sugar increases levels of glucose (sugar) and insulin in the blood after the meal, known as hyperglycemia and hyperinsulinemia. Hyperglycemia/hyperinsulinemia after a meal has been found in young horses with OCD lesions. ^[29]

Insulin levels can also be impacted by health issues such as insulin resistance and obesity. In a study of the effects of maternal obesity, foals of obese mares had marginally different insulin sensitivity and high occurrence of OCD at 12 months of age but not at 6 or 18 months. ^[30]

However, not all studies with high starch feeding show an increase in OCD lesions. In one study, feeding a high starch diet was found to have no negative effects on biomarkers of cartilage metabolism or active growth hormone. In fact, there was a lower level of an anabolic biomarker during periods of low starch feeding ^[14]. A study comparing normal to osteochondrotic horses found the normal horses were more insulin resistant than the ones with OCD. ^[31]

Instead of diet composition, the main risk factor associated with developmental orthopedic disease is rapid growth, which can be induced by feeding young horses high calorie meals of any composition.

Best Calorie Sources

Provide additional calories in the form of fat and fibre to avoid significant increases in blood glucose or insulin. ^[16] In addition to forage, the safest calorie sources for growing horses include:

• Roasted soybeans
• Alfalfa pellets or cubes
• Oils such as w-3 oil, canola oil, flax oil or camelina oil (in appropriate amounts)
• Beet pulp
• Wheat bran

Work closely with a nutritionist when feeding alfalfa or by-products, such as beet pulp or rice bran, as these need to be carefully balanced in the diet to avoid mineral imbalances, which can be detrimental to growth.

4) Provide High-Quality Protein Sources

Providing enough protein is critical to support your foal’s growth and development. Foals who don’t get enough protein can experience growth retardation, even if the diet provides adequate energy. ^[17]

Not all protein sources are equal. High-quality protein is readily digested in the foregut and provides a balanced profile of essential amino acids, which the body can not make.

In particular, lysine is the most limiting amino acid in equine diets. This means it is most likely to be deficient to the point of reducing overall protein synthesis in the body.

The diet of growing foals must provide enough protein and lysine to optimize growth. High-quality protein and amino acid sources include:

• Soybean meal
• Roasted soybeans
• Whey
• Pure amino acid supplements, such as Three Amigos

The inclusion level of additional protein sources will depend on the protein content of your forage, other feeds in the diet and how well your foal is growing. A nutritionist can help you determine which protein sources should be added and how much to feed.

5) Meet Vitamin and Mineral Requirements

To optimize growth, it is also necessary to ensure your foal’s vitamin and mineral requirements are met and that these nutrients are provided in optimal balance. ^[18]

Mineral and Vitamin Requirements of Growing Foals

The following minimum mineral and vitamin requirements are based on a growing foal with an estimated mature weight of 500 kg / 1,100 lb.

Mineral and vitamin requirements are typically based on avoiding deficiency symptoms, however they do not necessarily reflect supporting optimal health. There is evidence that increased intake of copper above the requirement improves the healing of OCD lesions. ^[26][27] It is common practice to enrich feeds for mares and foals with higher levels of copper and zinc.

Besides OCD, significant vitamin and mineral deficiencies can contribute to the following diseases in growing horses:

• White muscle disease: Linked to selenium deficiency and, to lesser extent, vitamin E deficiency
• Neurological disorders: May be associated with vitamin E deficiency, as in Equine Motor Neuron Disease and Equine Neuroaxonal Dystrophy
• Rickets: Insufficient calcium and/or phosphorus
• Goiter: Iodine deficiency (or toxicity)

Obtaining a forage analysis is the best way to assess mineral levels and balance your foal’s diet accordingly.

It is also well-established that hay does not provide vitamin E, as these are rapidly degraded when the grass is cut for hay. ^[19] Vitamin A may also be inadequate, particularly in hays that are stored for more than 12 months. Foals on hay alone will likely need these vitamins supplemented in the diet.

Calcium-to-Phosphorus Ratio

Having correct levels of calcium and phosphorus in the diet is particularly important for growing horses. These macrominerals are essential components of bone and are also critical for nerve signalling, muscle function, electrolyte balance and other metabolic processes.

A calcium-to-phosphorus ratio of 1.5 – 2 is ideal for growing foals, assuming both minerals are fed to their requirement. Foals can tolerate a ratio of up to 3:1 calcium to phosphorus so long as the phosphorus requirement is met. ^[28]

Depending on the ratio in your forage, your nutritionist may suggest feeding additional sources of these minerals.

Oxalates

Avoid feeding forages that contain oxalates or oxalic acid. Oxalates are organic acids that reduce calcium absorption in the gut and phosphorus retention in the body.

Grass species that can have high levels of oxalates include buffelgrass, Kikuyu grass, or Setaria (green foxtail). ^[18]

Calcium Sources

Feeds high in calcium include:

• Beet pulp – Contains 1% calcium
• Alfalfa pellets or cubes – Contains 1.5% calcium
• Milk replacer – Contains 1.0 – 1.5% calcium

Phosphorus Sources

Feeds high in phosphorus include:

• Wheat bran – Contains 1.38% phosphorus
• Wheat middlings – Contains 1.24% phosphorus
• Rice bran – Contains 2.22% phosphorus

Mad Barn’s Omneity® provides 10 grams of calcium and 5.6 grams of phosphorus per typical serving, sufficient to balance the majority of forages.

Omneity – Premix

5 stars		88%
4 stars		6%
3 stars		4%
2 stars		1%
1 star		1%

740 Reviews

Learn More

• 100% organic trace minerals
• Complete B-vitamin fortification
• Optimal nutrition balance
• Our best-selling equine vitamin

Trace Minerals

Trace minerals (also known as microminerals) are minerals that are required in small amounts, usually measured in milligrams (mg) per day. These include:

• Zinc
• Copper
• Manganese
• Iodine
• Selenium
• Cobalt

Most ration balancers and complete feeds will contain essential trace minerals, but depending on how much your foal is fed they may not provide enough of these minerals to meet requirements.

Organic Minerals

Many feeds contain a mix of organic and inorganic trace minerals. In general, organic (chelated) minerals are better absorbed and used by the body than inorganic minerals. ^[20]

Check the ingredient list of your feed to determine whether the minerals are provided as organic or inorganic forms.

Organic forms include mineral proteinates, amino acid complexed minerals, mineral polysaccharides, Bioplex minerals, and mineral propionates. Inorganic forms include oxides, chlorides, carbonates, and sulfates.

Mad Barn’s Omneity® contains 100% organic trace minerals in proper ratios for optimal absorption and utilization by the growing horse.

6) Consider Additional Supplements

You may wish to provide additional nutrition support depending on your foal’s health history, growth patterns, and exercise level. Consult with your nutritionist to discuss adding supplements to your foal’s diet.

Joint Health

Regulating calorie intake while meeting protein, vitamin and mineral requirements is the best way to support healthy joint development and decrease the risk of DODs in growing foals.

In addition, giving your foal appropriate turnout and exercise helps growing horses develop healthy bones and joints.

By five months of age, foals with free access to pasture show optimal bone development. In comparison, excess exercise and stall confinement result in abnormal bone development. ^[21]

Feeding omega-3 fatty acid supplements also supports joint health and function. In 2-year-old horses, providing fish oil as a source of docosahexaenoic acid (DHA) and eicosapentanoic acid (EPA) was shown to increase trot stride length. ^[22]

Mad Barn’s w-3 oil provides 1,500 mg of microalgal DHA per serving and is more palatable for horses than fish oil. A 60 mL (2 oz) feeding rate for a growing horse would be sufficient to provide DHA while maintaining a lower calorie supply.

w-3 Oil

5 stars		79%
4 stars		10%
3 stars		7%
2 stars		2%
1 star		2%

630 Reviews

Learn More

• Promotes joint comfort
• Helps to fight inflammation
• Skin & coat condition
• Palatable source of Omega-3's

Cognitive Development

DHA and EPA may also support healthy brain development. In human infants and animal models, supplementing these fats during pregnancy supports brain development in utero and helps decrease the risk of mental health disorders. ^[23]

One study found that foals born to mares supplemented with DHA during pregnancy had better memory and learning abilities at one and two years of age. ^[24]

Post-Weaning Example Diets

These example diets are based on the needs of a growing foal in light exercise with an estimated adult body weight of 500 kg / 1,100 lb.

It is critical to continue to monitor and record your foal’s growth and make dietary adjustments as needed. A nutritionist can help you balance the diet to ensure all requirements are still met while supporting healthy growth.

Diets for Growing Foals

The following foal feeding program is based on a horse with an estimated mature weight of 500 kg / 1,100 lb.

*Protein content of the forages in this sample diet is provided on a dry matter basis.

Summary

Proper nutrition and care are essential to supporting the healthy growth of your foal through their first year of life. The main goals during this phase of development include:

• Avoiding erratic growth patterns by frequently adjusting the diet to match needs
• Introducing feeds around 2-3 months after birth and continuing the diet post-weaning
• Meeting protein requirements with high-quality forages
• Avoiding excess calorie supply to support joint health
• Ensuring that vitamin and mineral requirements are met by feeding a balanced nutritional supplement and salt
• Consider adding DHA from w-3 oil to support joints and cognitive health

Want to see how your foal’s diet is meeting their predicted nutrient requirements? Submit your foal’s diet online for a free analysis by our qualified equine nutritionists to get individualized recommendations for feeding and management.