Growing Horses, Foundations of Good Nutrition, Nutrition

Feeding Weanling Horses

Feeding weanling horses

Weaning can be a very stressful time for a young horse and his or her dam. Strategies such as progressive weaning or weaning foals in groups can reduce stress around weaning. Correct nutrition and strategic use of probiotics before, during and after weaning can contribute significantly to the health and well-being of mare and foal alike.

Start-of-life nutrition is critical to the development strong bones, muscles and connective tissue as well as the internal organs, including heart and brain. The impacts of nutritional insufficiencies during growth can last a lifetime, effecting long-term health, soundness and even behaviour.

If your broodmare has been fed correctly through pregnancy and lactation, your weanling has had every chance to develop a strong body, good immunity and digestive health for better resilience through weaning and beyond.

Prior to weaning, your foal would have most likely have been sharing the mare’s roughage and hard feed, taking an increasing share of her food each week. As the foal starts eating more grass, hay and hard feed it will drink less milk so the mare’s feed requirements begin to reduce gradually.

During the first week of weaning, continue to feed the foal the proportion of each meal you estimate s/he was taking from the mare’s feed. Do not change ingredients of the foal’s ration during weaning.

If this feed was well balanced, little will need to change in the foal’s ration in the first weeks post-weaning (see the section below for details on how to formulate a well-balanced ration for your weanling).

Do not make sudden changes to the weanling’s diet. Make changes to the diet over a 10 to 14 day period, gradually increasing the amount of new feeds as you slowly phase out the old.

Weaning time is hard on the mare too, due to stress and the risk of mastitis. Stop giving the mare grain/pellets for a few days after the foal has its last drink of milk. Feed the mare grass hay and dry pasture supplemented with mineral balancer pellets or powders mixed into a token hard feed. Avoid lush grass and do not hard feed the mare until her udder softens.

The stress of weaning can have negative impacts on the digestive tract and beneficial gut flora, often leading to digestive upset and diarrhea in both mare and foal. If severe, colic and laminitis can occur. Research demonstrates that use of oral probiotics, including strains of live yeast from the genus Saccharomyces, reduce diarrhea and gut acidity and help to maintain a more stable gut microbiome during times of stress.


1.    Roughage is always the basis of a healthy ration

The first rule of good horse nutrition is to feed plenty of roughage as pasture, hay or chaff.  Unless your weanling is overweight, it is safe to feed as much grass-based roughage as s/he will eat. When the pasture is not plentiful, replace it in the diet by providing grass hay.

Nutrition pyramid for feeding weanling horses

Figure 1. Equine Nutrition Pyramid for a weanling. Roughage forms the foundation of any well-balanced horse diet. Weanlings will usually need a protein supplement to provide adequate amino acids for growth and development. Some weanlings can get all the energy required from roughage alone but it is common to need to supplement with an energy source at some times of the year and during growth spurts to avoid a drop in body condition. The percentage of the diet provided as an energy concentrate varies significantly depending on foal breed, growth rate and pasture quality. A quality vitamin/mineral supplement, salt and an omega-3 fatty acid source are necessary to complete dietary balance.

2.    Ensure Enough Quality Protein in weanling diets

Weanlings need high quality protein in their diets – especially lysine, a key amino acid which they are unable to produce in their bodies. Other important essential amino acids are methionine, threonine and leucine.

Legume forages and grains including lucerne, clover and soybean meal are effective options for adding essential amino acids to growing horse rations and are commonly found in commercial feeds formulated for breeding horses. Pure amino acid supplements can also be used in carefully calculated amounts to meet shortfalls if necessary.

Weanling diets deficient in essential amino acids will produce stunted animals with poor muscle development.

Growing horse bodyweight and dry matter intake

Figure 2. As weanlings mature towards their mature body weight, they eat more (dry matter intake). Most of the increase in intake should be forage.


Growing horse energy and protein requirements

Figure 3. Weanlings need more digestible energy (measured in calories or megajoules) and protein than yearlings and two year olds. By three years of age, the energy and protein requirements are similar to those of a mature horse.

The relatively high requirement for protein and lysine (Figure 3) coupled with the smaller daily intake of a weanling (Figure 2) means that weanlings need a diet with a higher percentage of high-quality protein than mature horses.

3.    Only Add Calories if Necessary

Weanlings only need an additional calorie source if they lose weight or grow too slowly on all-they-can-eat forage plus enough protein. This can occur due to a reduction in pasture or hay quality or when the foal has a growth spurt.

Pasture quality is highest in young, leafy plants and declines as the plants mature and dry off.

The best way to determine a weanling’s energy requirements is to carefully and regularly monitor body condition score and, if possible, measure growth rate by regularly weighing on scales.

Body Condition, Growth Rates & Developmental Orthopaedic Disease

Veterinary advice to reduce the risk of growing horses developing OCD is to limit calories to prevent very fast growth whilst ensuring enough amino acids, vitamin, minerals and polyunsaturated fatty acids (especially omega-3s) are provided for development of strong bones , muscle and other tissue.

Foals and weanlings should not be overweight – aim to maintain body condition score (BCS) at 4.5 to 5.5 on a 9 point scale. You want to be able to just see the ribs – and always ensure that ribs can be felt in growing horses.

4.    Balance with vitamins, minerals and oils for weanlings

It is critical to provide vitamin and mineral supplementation to satisfy your weanling’s daily requirements. Failure to do so will compromise the long-term structural soundness of your young horse.

Forages and protein sources do not contain enough minerals to meet basic requirements, let alone provide optimum and balanced levels.  Weanlings usually require more calcium, sodium, phosphorous and manganese than that provided by pasture. All equine forage-based diets need added copper, zinc, iodine and often selenium. It is also essential that the critical mineral ratios are balanced over the entire diet to optimise availability and uptake.

Growing horse calcium and phosphorous requirements

Figure 4. A growing horse’s calcium and phosphorous requirements are much higher during the first two years than in later life. A weanling’s diet must contain supplementary calcium and phosphorous with the levels balanced over the whole intake to provide approximately twice as much calcium as phosphorous.

Growing horse copper and zinc requirements

Figure 5. All horses need supplementary copper and zinc to complement the level of naturally occurring iron in the rest of the intake. Copper requirements remain steady from weaning to maturity, but the zinc requirement increases as the foal matures.

Vitamins and oils are also important to sustain healthy growth and development in young horses. Green, leafy pasture is rich in most of the vitamins that horses require, but vitamin levels decline in mature and drying off plants, including hay. It is advisable to provide weanlings with a source of supplementary vitamins, including vitamins A, B, E, K, folate and biotin.

A small amount of oil is also essential in any equine diet. Ensuring a good balance of omega-3 polyunsaturated fatty acids relative to omega-6 is important for many reasons, including correct functioning of the immune system.

Green leafy plants are high in omega-3 in the form of ALA but levels rapidly decline in dry plants and hay, therefore a supplementary form of omega-3 is needed when green grass is not available.

Once inside the body, some ALA is converted into two other, more active forms of omega-3 fats – DHA and EPA which are are vital to the development of healthy hearts, brains, skin and joints.

Farmalogic Omega Balancer is a palatable and stable omega-3 supplement which is even more potent and effective than linseeds or linseed/flax oils due to the DHA/EPA content from marine-sourced omega-3.

Do I need to feed a commercial breeding horse pellet?

A quality breeding-specific commercial premixed feed can simplify the process of feeding your weanling a well-balanced diet, but only when they need the full daily recommended amount of the feed. If he or she needs less calories than the feed provides, you will need to separately supplement extra protein and mineral levels to avoid a deficiency.

For this reason, it may be simpler to provide a protein source and vitamin, mineral and omega-3 supplements separately from the energy source. This allows you to easily change the diet in response to seasonal changes as well as your yealing’s changing needs over time.

If I mix my own concentrates, what sorts of feed should I use?

1. Extra energy to top up calories from roughage if required.

  • Super Fibres – energy sources that are high in digestible fibre. These include beet pulp (e.g. Speedibeet, Microbeet), copra, soy hulls (e.g. Maxisoy), other legume hulls such as lupin hulls.
  • Legume grains – the most commonly available is lupins. Legumes also contribute a concentrated source of protein to the diet. Due to their hard seed coat, buy processed lupins or soak whole or cracked lupins to soften prior to feeding.
  • Cereal grains – oats contain starch in a form which is easily digested by horses when fed raw. Other cereals such as barley and corn are poorly digested unless cooked so feed them boiled, extruded, micronized or pelleted. Cereal by-products such as bran, pollard and millrun are lower in energy than whole grains.
  • Fats and oils – can be used judiciously to boost the energy density of diets but must be introduced very gradually to avoid upset. Take care to maintain the right omega-3 to 6 balance.

2. Extra protein to top up amino acids – especially those high in lysine

  • Lucerne, clover or other legumes in the hay or pasture.
  • Full fat soybean meal (only ever buy correctly processed soybeans which have been cooked to remove trypsin inhibitors).
  • Pure amino acid supplements.
  • If using legume grains such as lupins for energy, they will contribute crude protein to the diet, but are lower in lysine than soybeans.

3. Vitamins and minerals for weanlings

  • A quality vitamin and mineral supplement rich in macrominerals, trace minerals and vitamins. Equine Vit&Min is designed to balance mineral ratios across the whole diet.
  • Salt – sodium chloride can be purchased as table salt, stock salt, flossy salt or pool salt.
  • Omega-3 balancing oils or powders. These need to contain more omega-3 than 6 in able to balance the high omega-6 levels naturally occurring in diets where green grass is limited. Consider choosing one which contains DHA and EPA rather than ALA alone.
  • Consider a probiotic live yeast so your weanlings can get better value from the food they eat. Saccharomyces cerevisiae live yeast is scientifically proven to boost forage utilisation by turning indigestible fibre into usable energy.


Roughage (pasture, hay or chaff) forms the foundation of every healthy horse diet. It must be balanced with vitamins, minerals and omega-3 fatty acids.

Not all weanlings require an energy source (like grain, beet pulp, oil, pellets, formulated blends) especially when pastures are lush and green. A vitamin and mineral balancer and is all that is required.

The need for a hard feed depends on weanling body condition and the energy and protein content of their roughage source, and that varies according to seasonal factors. Some may need an energy boost when pasture is not growing well but won’t need any added calories during the spring pasture flush.

If you feed a bagged ‘complete feed’, you’ll need extra vitamins and minerals when you feed less than the recommended amount from the bag. If you mix your own hard feeds and incorporate a comprehensive all in one vitamin and mineral supplement you can easily make changes to the energy and protein content of the diet as necessary.

It can be a wise investment (for your pocket as well as your horse’s health) to seek the advice of a qualified equine nutritionist during this critical stage of the life of your young horse. Farmalogic proudly offers a complementary diet analysis service to horse-owners throughout Australia and New Zealand.

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