Tag Archive for: feed ingredients

Feeding Flaxseed

Flaxseed (also known as linseed) is a valued feed ingredient amongst horse people. How it should be used has long been the subject of considerable debate. Its safety for horses has always been under question and methods of preparation are many and varied. This article looks at what flaxseed can add to your horse’s diet, if it is safe to feed and how it can be prepared for feeding.

What does flax add to a diet?

Flaxseed’s best known attribute is its high Omega 3 essential fatty acid content. Flaxseeds are over 40% oil and more than 50% of this oil is the omega 3 fatty acid α‐linolenic acid. A horse’s natural grazing diet is high in omega 3 fatty acids. However as we add grains like corn and barley to a horse’s diet their diet can become skewed towards having high levels of omega 6 fatty acids. Flaxseed provides a ‘natural’ way to keep the levels of omega 3 in a horse’s diet balanced without using expensive omega 3 fatty acid supplements. Adding 100 grams of flaxseed to your horse’s diet will add over 20 ml of omega 3 fatty acids.

While omega 3 fatty acids are generally the primary reason flaxseeds are fed to a horse, flaxseeds are a decent source of protein with around 24% protein and 0.9% lysine and also contain around 25% fibre.

When can flaxseed be used?

Flaxseed is useful for horses on a high grain (and therefore high omega 6 fatty acid) diet or when they are eating hay that has been in storage for some time or grazing low quality pasture. Flaxseed may also be used when horses have a dry coat and skin, if they have problems with inflammation including arthritis and sweet itch/Queensland itch or when high omega 6 oils like corn oil or sunflower oil are being fed as an energy source in the diet. Flaxseed itself can be used as a source of energy in the diet and because of its high fat attribute is often found in supplements intended to promote weight gain in horses.

How should flaxseed be prepared for feeding?

Because flaxseed is such a small seed it is best to grind flaxseeds immediately prior to feeding to break the seed coat, otherwise the seeds will pass undigested all the way through the gastrointestinal tract. It is important to grind the seeds fresh just prior to feeding as the oils in flaxseed are prone to rancidity and will go off very quickly if ground and left exposed to air. A small coffee grinder is commonly used for the purpose of grinding fresh flax straight into a horse’s feed (very gourmet!).

It is possible to purchase pre‐ground and stabilised flaxseeds if grinding your own is not an option.

Does Flaxseed have to be boiled before feeding?

Tradition says that flaxseed must be boiled before feeding it to a horse because of the risk of Prussic Acid (or hydrogen cyanide) poisoning. Anyone who has boiled flaxseed knows how messy it gets and for most the effort and mess are too much to continue persisting. Well good news … flaxseed it seems can be fed safely without being boiled.

Flaxseed contains compounds called cyanogenic glycosides. When the flaxseeds are chewed up by a horse these cyanogenic glycosides come into contact with an enzyme (β‐glycosidase) which converts it to hydrogen cyanide, which can then lead to cyanide poisoning. HOWEVER, the β‐glycosidase enzyme is destroyed by the acidic environment of the horse’s gastric stomach, meaning the cyanide is never produced in quantities large enough to cause any problems. This means you can feed flaxseed without cooking it first.

A study published in the Canadian Journal of Veterinary Research in 2002 looking at the ability of flaxseed to reduce the inflammation associated with culicoides hypersensitivity (sweet itch or Queensland itch) reported that they fed 1 lb of flaxseed per 1000 lb of bodyweight to horses (or 0.5 kg per 500 kg bodyweight) over a period of 42 days with no negative side‐effects being observed. With this dose rate being much higher than the normal 1 to 2 cups fed per day it can be concluded that flaxseed is safe to feed to horses without cooking it first.

What about soaking it?

It is possible that soaking flaxseed may actually make it dangerous as soaking the seeds would, to some extent, allow the β‐glycosidase enzyme to come into contact with the cyanogenic glycosides and allow for the production of hydrogen cyanide. So it is recommended you do not soak flaxseed before feeding.

Can flaxseed meal be fed?

Flaxseed meal is the high protein (32%) meal left over after the flaxseed oil has been extracted from the seed. Flaxseed meal can be fed to horses, however because the meal has had most of the oil extracted its primary use in a horse’s diet is as a protein supplement. The risk of cyanide poisoning from flaxseed meal is a little unclear. Because the seed is crushed during the oil extraction process it is possible for the β‐ glycosidase enzyme to come into contact with the cyanogenic glycosides, so it is likely hydrogen cyanide will be present. If you wish to feed flaxseed meal, look for meal produced using heat extraction technology as opposed to meal made from seeds that were cold pressed. There are however far better sources of quality protein available including lupins, full fat soybean, soybean meal and canola meal, without the possible risk associated with flaxseed meal.

Other possible side effects

Flaxseed contains phytoestrogens. Phytoestrogens are naturally occurring plant compounds that are structurally similar to estrogen. Studies in rats (Collins et al 2003) have found that feeding high levels of flaxseed to rats increased the number of female rats with irregular estrous cycles, suggesting flax could have a negative impact on the fertility of breeding animals. If you are breeding your mares and having any type of fertility problems it would be wise to avoid flaxseed in their diets.


Flaxseed is a useful feed ingredient for horses. It can be used to increase a horse’s omega 3 essential fatty acid intake where dietary omega 3 levels are low or when higher intakes of omega 3 for a particular horse seem beneficial. Despite popular opinion that flaxseed must be cooked prior to feeding to avoid hydrogen cyanide poisoning, studies have shown that up to 1 lb/1000 lb bodyweight (or 0.5 kg/500 kg BW) can be safely fed without cooking. Flaxseed should not be soaked prior to feeding and they should be avoided in the diets of breeding mares with a history of reproduction problems. FeedXL can be used to incorporate flaxseed into your horse’s diet so that it balances well with other feed ingredients being fed.

Meet The Author: Dr Nerida McGilchrist

Dr Nerida McGilchrist is FeedXL’s co-founder and equine nutrition specialist. She holds a degree in Rural Science, a doctorate degree in equine nutrition and nearly 20 years of full time, on the ground experience in feeding all types of horses. To learn more about Nerida and to ‘meet’ the rest of the FeedXL team, check out our About Us page here.



Do you have a question or comment? Do you need help with feeding?

We would love to welcome you to our FeedXL Horse Nutrition Facebook Group. Ask questions and have them answered by PhD and Masters qualified equine nutritionists and spend time with like-minded horse owners. It’s free!

Click here to join the FeedXL Horse Nutrition Facebook Group


Seaweed for Horses: Miracle Supplement or Massive Con?

There has been much debate about the potential benefits to be gained from feeding seaweed to horses. On one side, we have seaweed being reported as a multifunctional supplement that will act as an anthelmintic, antacid, immuno-stimulator, anti-inflammatory, anti-cancer, anti-bacterial, anti-ulcer, heavy metal scavenger, fertility enhancer, nerve calmer, thyroid stimulator and skin and coat conditioner. From the other side, seaweed is called nothing more than a con, containing potentially dangerous levels of iodine and precious little of anything else. So who is right, and is there any middle ground to be sought in this argument?

What is Seaweed?

Seaweed is a marine plant that can be found in oceans all around the world. There are approximately 1700 different varieties of seaweed and they come in three different colours; green, brown and red. The green seaweeds generally grow close to the water’s surface and are smaller than the brown and red varieties. Brown seaweed grows in slightly deeper and often cold waters, while the red seaweeds grow in very deep waters. It is the brown seaweed (also called Kelp) that is commonly fed to horses in Australia.

Why Seaweed for horses?

Generally people will add seaweed to their horse’s feed to supply trace minerals that are lacking in the pasture, hay and concentrates being fed to the horse. Effectively, seaweed is used as a trace mineral supplement.

Is Seaweed a Good Trace Mineral Supplement?

Seaweed supporters will readily tell you that seaweed contains ‘every nutrient needed by the horse’ including 48 minerals, 16 amino acids and 11 vitamins, making it sound like a very attractive and natural option for trace mineral supplementation. However, the concentration of minerals in seaweed is so low that when fed at the levels generally recommended for horses (15 to 30 grams/day) it makes virtually no contribution to satisfying a horse’s trace mineral requirements, with the exception of iodine (Table 1).

Table 1: The percent of daily nutrient requirements for a 500 kg horse in light work satisfied by 20 grams of seaweed containing 600 mg/kg of iodine or by 20 grams of a well formulated commercial trace mineral supplement.

% of daily requirement
satisfied by 20 g of
% of daily requirement
satisfied by 20 g of a
commercial trace
mineral supplement
Copper 0.01 62
Zinc 0.06 44
Selenium 0.1 52
Manganese 0.05 44
Iodine 706 68
Iron 1.96 35

When it comes down to it, seaweed gives your horse very little benefit from a trace mineral perspective (with the exception of iodine, which is grossly oversupplied), particularly when considered in comparison with a well formulated commercial supplement.

How Much Iodine Does Seaweed Contain?

The iodine concentration of seaweed is generally highly variable and depends on many factors including the variety of seaweed and the age of the blades that were harvested and analysed. In a study conducted in 2004 (Teas et al.) researchers found that the concentration of iodine in 12 different seaweeds varied from 16 mg/kg to 8165 mg/kg. They also found that within the same variety of seaweed, iodine concentration ranged from 514 mg/kg of iodine in the older sun‐bleached blades to 6571 mg/kg in the juvenile, fresh blades, demonstrating the highly variable concentrations of iodine that may be present in a seaweed product.

How Much Iodine Do Horses Need?

Horses require between 0.35 and 0.4 mg of iodine/kg of dry matter consumed per day. Thus a 500 kg horse consuming 2% of its body weight in feed per day will need between 3.5 and 4 mg of iodine per day. Iodine toxicity will occur at intakes of 5 mg/kg of dry matter consumed per day, which is equal to approximately 50 mg/day for a 500 kg horse.

Can Seaweed Cause Iodine Toxicity?

YES! Iodine toxicities can definitely occur when horses are fed too much seaweed. So, how much seaweed is too much? Well, that all depends on the concentration of iodine in the seaweed. Eighty grams of seaweed that contains 600 mg/kg of iodine will need to be fed to cause acute iodine toxicity in a 500 kg horse, while just 6 grams of seaweed containing 8000 mg of iodine/kg will cause acute toxicity in the same horse.

Chronic toxicity may also be a problem in horses. The effects of feeding relatively high concentrations of iodine to a horse over a long period of time (for example you may feed 20 grams per day of a 600 mg/kg iodine seaweed for 6 months, providing your horse that has a requirement of 2 mg of iodine/day with 12 mg of iodine per day) have never been studied in horses. Studies in humans however (Pearce et al. 2002; Mizukami et al. 1993) have shown that iodine toxicity can be precipitated through long term exposure to moderately high concentrations of dietary iodine. Thus the answer to the question ‘how much is too much?’ is ‘we don’t know’, meaning seaweed must be fed with extreme caution, if it is to be fed at all.

Is There Any Time That Seaweed Is Useful in a Horse’s Diet?

Given the high iodine concentration in seaweed, it can be useful to feed as an iodine supplement when there is a demonstrated iodine deficiency. Remember that an iodine deficiency will cause virtually exactly the same symptoms as an iodine toxicity (goitre, a dry, lustreless coat, lethargy, dullness, drowsiness and timidity, inappetence and cold intolerance). Thus the only way to diagnose and differentiate an iodine deficiency from toxicity is to carefully analyse the iodine content of the feeds your horse is eating. If an iodine deficiency is diagnosed and you decide to feed seaweed, carefully calculate the amount required by your horse using the iodine concentration specified on the particular product you are using. Do not overfeed seaweed in an attempt to rapidly correct your horse’s iodine deficiency as you will end up correcting the deficiency only to cause a damaging toxicity.

4 Things You Must Do Before You Feed Seaweed to Your Horse

  1. Consider exactly why you want to feed seaweed. If you can’t pinpoint a good reason such as a demonstrated iodine deficiency, then it is probably best you don’t feed seaweed at all.
  2. Obtain the iodine content of the seaweed product you wish to use. If the product you are considering does not specify its iodine content do not feed it. Never feed your horse anything unless you know what is in it. If you have your seaweed tested for iodine concentration, send us the analysis at FeedXL and we can put your specific analysis with the tested iodine level into your personal FeedXL database.
  3. Using the products specified iodine concentration, calculate how much you need to feed per day to satisfy but not substantially exceed your horse’s iodine requirements. When using FeedXL, this is easy. Simply put enough seaweed meal into your horse’s diet to meet the calculated iodine requirement. No pen and calculator required.
    FeedXL will also make sure that if your horse is being fed other iodine-containing supplements these are taken into account.
  4. Carefully weigh and feed the calculated amount of seaweed to your horse each day. Never give your horse free access to seaweed; this will just be an iodine toxicity waiting to happen.

A Special Note about Seaweed for Mares and Foals

There is a particular risk in feeding seaweed to pregnant and lactating mares. Excess dietary iodine accumulates in the placenta and is excreted in milk. Thus foals born to mares consuming diets high in iodine will be at risk of developing iodine toxicity. Foals from these mares may be born dead, or very weak, with a poor suckle response. Those who live and continue to suckle from their dam will likely develop skeletal abnormalities as iodine toxicity causes low serum thyroxine hormone concentrations and the thyroxine hormone is crucial for cartilage maturation and bone formation.

The Final Slime…

Think carefully about feeding seaweed to your horse. If your horse doesn’t need additional iodine in its diet then I would suggest you don’t feed seaweed. If you do decide to feed it, do so with extreme caution, ensuring that you always use FeedXL to calculate the amount to feed and weigh and feed that amount accurately. Don’t guess, it’s definitely not good for your horse’s health!

Meet The Author: Dr Nerida McGilchrist

Dr Nerida McGilchrist is FeedXL’s co-founder and equine nutrition specialist. She holds a degree in Rural Science, a doctorate degree in equine nutrition and nearly 20 years of full time, on the ground experience in feeding all types of horses. To learn more about Nerida and to ‘meet’ the rest of the FeedXL team, check out our About Us page here.



Do you have a question or comment? Do you need help with feeding?

We would love to welcome you to our FeedXL Horse Nutrition Facebook Group. Ask questions and have them answered by PhD and Masters qualified equine nutritionists and spend time with like-minded horse owners. It’s free!

Click here to join the FeedXL Horse Nutrition Facebook Group


Grains for Horses: Cooked or Uncooked?

While a lot of time is spent focussed on horses that can’t eat grain in their diet, cereal grains such as oats, barley, triticale, corn, rice, rye, sorghum and wheat form a valuable component of many horse’s rations. Selecting the most digestible grain based feed however can be confusing, with uncooked grains like whole, cracked and crushed grains being available as well as cooked grains like extruded, micronised, steam rolled or steam flaked and pelleted grains.

The question is, which form of grain is best for your horse, cooked or uncooked?

Why we cook grains

Grains are fed primarily as a source of energy in a horse’s diet and that energy is derived mainly from the white starch found in the centre of the grain. For the horse to obtain the energy from the starch it must be digested by enzymes in the small intestine.

But digesting the starch to extract the energy is not easy for the horse because it is “packaged” within the grain in a way that makes it difficult for the horse to get to. The reason grains are cooked is to make access to the starch a lot easier for the horse.

How starch is “packaged”

Starch is simply many glucose molecules all bonded together and bundled up into starch granules. These starch granules are then embedded amongst protein in a structure known as the protein matrix (Figure 1).


Figure 1: A scanning electron micrograph of the middle of a barley grain showing the starch granules embedded within the protein matrix. The starch granules are the large round objects.


The starch granules, embedded in the protein, are then encased within individual endosperm cells and protected by a cell wall. Many of these cells are packed tightly within the grain’s starchy endosperm (the white bit found in the middle of a grain). And the endosperm itself is protected by the aleurone layer and finally the entire structure is covered by the seed coat (Figure 2). Now from the plant’s perspective, all of this packaging is absolutely critical for its survival and is designed to protect the plant embryo and its stored sources of energy and protein to ensure it will be able to grow and survive for the first few days following germination.


Figure 2: The location of starch granules (stained black) within the endosperm cells of barley grain surrounded by the protein matrix (stained green) and protected by the aleurone layer and seed coat.


So, the packaging is clever and essential from the plant’s perspective, however for the horse, all of this packaging is just a nuisance and prevents the horse from being able to digest and extract the energy from the grain. In fact, this packaging was actually specifically designed to allow a grain to pass through the gastrointestinal tract of an animal undamaged so it may germinate when it is excreted in the manure.

How does this packaging stop starch digestion?

The packaging can be likened to a security system at a casino which prevents the thieves (or in this case the enzymes) from stealing the cash (the starch). To digest the starch the enzymes in the horse’s small intestine must first breech the seed coat, then penetrate the aleurone layer. Following this they need to be able to make their way through the endosperm cell walls (these are the cells that contain the starch), then burrow through the sometimes impenetrable vault of the protein matrix before finally reaching the starch granule. Then, in a cruel twist of fate, if the enzyme reaches this far, it will find that the starch is bundled so tightly into a ball that the enzymes cannot digest it. So the horse is presented with a difficult hurdle—just how does it go about extracting the energy held in the starch of cereal grains?


Enter cooked grains…

It has been recognised for many years now that to effectively digest cereal grains, horses need some help. And that help comes in the form of ‘cooking’. Cooking grains using processes like extrusion, micronising and steam flaking breaks down the barriers the enzymes have to face in reaching and digesting cereal grain starch.

How cooking helps

When grains are cooked using a combination of heat, moisture, pressure and some form of physical process like rolling or grinding, the entire structure of the grain is disrupted. To start, the seed coat and aleurone layer are broken and the endosperm cell walls are opened up. In addition, the structure of the protein matrix is physically disrupted so it is no longer able to protect the starch granules. Cooking also turns the ordered and tightly packed structure of the starch granule into an open and vulnerable structure which can be easily attacked by enzymes in a process known as gelatinisation. Cooking simply gives the horse’s enzymes access to the grain starch so they can go about their work of cutting up the starch into single glucose molecules, which the horse then absorbs from the small intestine into the body, where it is used for energy.

What about cracked grains?

Simply cracking, crushing or grinding grains is the same process as chewing and aims only to change the physical structure of the grain, breaking the seed coat and reducing the grains particle size to give the enzymes better access to the starch within the centre of the grain. While the seed coat and aleurone layer barriers are removed, physical processing only causes minor damage to the endosperm cell walls and leaves a majority of the protein matrix and starch granule structure intact, meaning only small improvements to starch digestion will be made. Work conducted in horses showed that cracking corn only improved its digestibility in the small intestine of the horse by 1%. So while physical processing can get an enzyme through the front doors of the casino, gives them access to some of the cash floating around at the tables, and maybe even gets them into the strong room, it leaves the enzymes without a key, security code or set of explosives to get it into the vault. In short, they aren’t much better than whole grains.

Does soaking grains help?

Soaking grains simply makes them much easier to chew, so soaking will help the horse to break the seed coat and aleurone layer barriers. However soaking does nothing to disrupt the endosperm cell wall, protein matrix or starch granule structure, so, like cracking grains, soaking does not help to improve starch digestion.

What happens if cereal grains are fed without being cooked?

Starch from grains fed whole or cracked will remain largely undigested as it passes through the small intestine and will eventually be delivered to the hindgut. This is where the trouble begins. The bacteria in the hindgut do not face the same barriers as the enzymes in the small intestine, and they are able to reach and rapidly ferment the starch contained in uncooked grains. This rapid fermentation of starch causes excessive production of acids, which accumulate in the hindgut and lower the hindgut pH (the hindgut contents become acidic). Low pH in the horse’s hindgut causes a multitude of diseases and behavioural disturbances including laminitis, colic, endotoxaemia, systemic acidosis, reduced fibre fermentation, poorappetite, wood chewing and the eating of bedding as well as deficiencies in the B-group vitamins (including biotin) and vitamin K.

What about oats?

The general consensus is that oats can be fed unprocessed. As it is a larger grain, horses are capable of chewing the grain enough to break its seed coat, removing the need for physical processing. Studies have also found that oat starch is far easier to digest than corn or barley starch in an uncooked form. So oats can be fed whole and uncooked. However, whether oats can be fed unprocessed needs to be decided on a horse by horse basis. Observe your horse’s manure closely when you are feeding him oats. If you observe whole oat grains in his manure, whole oats is not a suitable feed for this horse. It is important to make sure the oats you are observing in the manure are whole and not just undigested hulls. Do this by taking them from the manure and squeezing them. If they are whole you will observe the white starch oozing from the centre. If you want to feed oats specifically, but your horse doesn’t digest them well, cracked, steam rolled and micronised oats can be purchased.

And the moral of the story…

Don’t feed cereal grains unless they have been cooked, with the exception of oats for some horses. If you feed whole, uncooked cereal grains, your horse will get little benefit from them and they have a good chance of causing disease and behavioural problems. Remember, the reason you feed cereal grains is to provide your horse with a source of energy. Most of this energy is held within the grain’s starch. If the horse can’t digest this starch, then you are better off not feeding the grain at all.

Meet The Author: Dr Nerida McGilchrist

Dr Nerida McGilchrist is FeedXL’s co-founder and equine nutrition specialist. She holds a degree in Rural Science, a doctorate degree in equine nutrition and nearly 20 years of full time, on the ground experience in feeding all types of horses. To learn more about Nerida and to ‘meet’ the rest of the FeedXL team, check out our About Us page here.



Do you have a question or comment? Do you need help with feeding?

We would love to welcome you to our FeedXL Horse Nutrition Facebook Group. Ask questions and have them answered by PhD and Masters qualified equine nutritionists and spend time with like-minded horse owners. It’s free!

Click here to join the FeedXL Horse Nutrition Facebook Group


Alfalfa (Lucerne) Hay: Friend or Foe?

Also known as lucerne in some parts of the world, alfalfa hay enjoys a varied reputation amongst horse people, with some using it as a highly valued component of their horse’s diet and others avoiding it with almost religious fervour. So, who is right? Is alfalfa hay a suitable forage for horses? Or are there other more suitable forages? The answer is yes, and yes. Alfalfa hay is a valuable forage for horses when fed to the right classes of horses and in the correct amounts for its full benefit to be realised. The following article looks at the nutrients contained in alfalfa hay and its many and varied uses in the horse industry.

Nutrient profile

Figure 1: A comparison of the digestible energy (DE), crude protein (CP), calcium (Ca), phosphorous (P) and magnesium content of early bloom lucerne hay, grass hay and oaten chaff.

Good quality alfalfa hay contains more protein and energy than grass or cereal hays and chaffs (Figure 1). Alfalfa also contains high concentrations of calcium and magnesium, and when fresh, the vitamins A and E. Alfalfa is typically low in phosphorous and depending on where it was grown, contains varying concentrations of other micro and macro minerals. The protein in alfalfa hay is of high quality and contains appreciable amounts of the essential amino acid lysine.

When to feed alfalfa?

To answer that question, we must consider the strengths and weaknesses of alfalfa hay. Firstly, note that there are no known anti‐nutritive factors in alfalfa hay. It is a very high quality, safe feed. However the higher energy and protein in alfalfa hay can result in too much energy and/or too much protein in the horse’s diet if you feed too much, so it is important to keep these nutrients in the diet within the recommended daily intake limits (RDI’s). Too much protein and/or energy can result in some problems for horses which are discussed below. As with all hays, some nutrients are lacking, particularly some of the trace‐minerals, so when feeding alfalfa hay it is important to ensure you are meeting the RDI’s when balancing your horse’s diet. The use of alfalfa hay in the diet of various classes of horses is discussed below:

1. Performance horses in training and competition

Alfalfa hay can be used to provide energy, good quality protein and a source of fibre to the diet of a performance horse; however, it must be used in moderation. Excess protein in the diet of working horses and particularly those that are stabled can be detrimental to their health and performance. Excess protein intake will increase urinary ammonia production, which may then result in respiratory problems for horses confined to a stable. Excess protein can also contribute to dehydration due to water loss through increased urine production and excretion and increases the amount of heat produced during the digestion and utilisation of feedstuffs. Therefore a diet containing protein in excess of the horse’s requirement can increase the horse’s water and electrolyte loss through sweating and can contribute to hyperthermia, and decreased performance or endurance capacity.

It is important to understand that these effects are not as a direct result of feeding alfalfa, but rather from feeding too much alfalfa. Avoid them by keeping protein within the RDI limits. Use a grass or cereal hay to supply some of the horse’s roughage/fibre requirement.

2. Spelling or idle horses

Alfalfa hay can play a role in the spelling or idle horse’s diet, and will provide these horses with good quality protein and calcium. If you keep energy and protein within your horse’s RDI, you can safely feed alfalfa without having excess weight gain due primarily to too much energy.

3. Ponies

Ponies may be safely fed alfalfa hay, but again it must be fed in moderation. Alfalfa hay, because of its highly digestible nature is capable of encouraging significant weight gain in ponies, particularly those that are easy keepers. Feeding too much alfalfa hay may therefore predisposeponies to laminitis, as the risk of laminitis increases when ponies become overweight (again, this is not as a result of feeding alfalfa, but as a result of feeding too much energy and protein which in turn leads to excess weight gain). Keep energy and protein within the recommended daily limits when using alfalfa in the diets of ponies.

Alfalfa hay is very useful in the diet of aged ponies. As horses and ponies age, they lose some ability to digest fibre and protein. Feeding them an easily digested fibre and high quality protein source in the form of alfalfa hay will help them maintain bodyweight, particularly in winter.

4. HYPP and laminitic horses

Alfalfa hay may not be suitable for horses suffering with hyperkalaemic periodic paralysis (HYPP) as its concentration of potassium is often quite high (14 – 25+ g/kg). Make sure you keep potassium in particular at the 100% RDI in these horses, regardless of the feeds you use.

In the reverse, and contrary to popular opinion, alfalfa hay is a very suitable feedstuff for horses that have suffered a bout of laminitis. The high quality protein in alfalfa hay will help the horse to repair its damaged laminae while the energy derived from the alfalfa will prevent these horses from entering a negative energy balance which slows or prevents the hoof’s healing process taking place. In comparison to some grass hays, alfalfa also contains a lower level of starches and sugars. Again, make sure you feed alfalfa hay in moderation to prevent excess weight gain; don’t exceed the energy and protein RDI’s in FeedXL.

5. Growing Horses

Alfalfa is a valuable forage in the diet of growing horses. Alfalfa provides growing horses with a digestible source of energy as well as a source of high quality protein and the essential amino acid lysine. Alfalfa’s calcium rich characteristic is also beneficial for growing horses that typically have high calcium requirements.

However, when feeding alfalfa to growing horses, the amount fed should not exceed the growing horse’s energy requirements. Growing horses fed energy in excess of their RDI’s have a much higher chance of suffering from developmental orthopaedic diseases including osteochondritis dissecans (OCD).

Feeding protein in excess of the growing horse’s protein requirements does not appear to be detrimental as the protein can be utilised as a source of energy. However, protein is an expensive source of energy and to quote Susan Garlinghouse “it is sort of like using bundles of dollar bills to start a barbeque. It’ll get the job done, but there are much cheaper, easier and more efficient ways of doing it”. Therefore, instead of using alfalfa hay to meet 100% of a growing horse’s energy requirements (which will far exceed their protein requirements) it would (depending on pasture conditions) be more economical to use some form of cereal grain or high energy fibre like sugarbeet pulp or soybean hulls to provide additional energy in the diet when needed.

Another point to be aware of when feeding alfalfa hay to growing horses is their intake of phosphorous. While feeding alfalfa hay to meet a growing horse’s protein requirements will also in most cases meet their calcium requirements, their phosphorous requirements will not be met. Feeding cereal grains will help to increase a growing horse’s intake of phosphorous, however, in many cases, phosphorous supplementation may be required (remembering that the calcium to phosphorous ratio in the diet of a growing horse should be maintained within the range of 1: 1 to 3: 1). Dicalcium phosphate is a suitable source of phosphorous for growing horses.

Also keep in mind that alfalfa hay is not a complete feed and will more often than not contain insufficient concentrations of trace minerals, in particular copper and zinc, to support sound musculoskeletal development. Thus diets utilising alfalfa hay as a protein and energy source must be balanced using an appropriate trace mineral supplement for the best results.

Once again, getting the diet balanced for the nutrient RDI’s in FeedXL is vital to making the best use of alfalfa.

6. Pregnant and Lactating Mares

Alfalfa hay is an exceptional source of energy and good quality protein for pregnant and lactating mares. Alfalfa hay will also help to support these mares’ elevated requirements for calcium and the essential amino acid lysine.

When feeding the pregnant mare alfalfa hay, take care not to exceed her energy requirements since this can cause her to become overweight. Pregnant mares should remain within a body condition score of 5 to 7 (using the Henneke scale of condition scoring) to prevent reduced milk production during the lactation period.

The lactatating mare’s energy requirements however are higher, and alfalfa hay alone will not be capable of meeting these and may, depending on pasture conditions, need to be fed in conjunction with cereal grains or high energy fibres to maintain body condition throughout lactation. Likewise, the lactating mare’s phosphorous and trace mineral requirements will not be met by a diet of alfalfa hay, thus these must also be supplemented accordingly.

As with growing horses, excess protein in the diet of pregnant and lactating mares does not appear to be harmful, however it is an unnecessary waste of this relatively expensive feed component and should be avoided if possible.

In Conclusion

Alfalfa is a valuable feedstuff for horses and is capable of providing them with energy, high quality protein, lysine, calcium and varying levels of other vitamins and minerals. However, alfalfa hay must be used correctly in the diets of all horses to realise its full benefits. Problems with the feeding of excess energy and protein are possible when feeding alfalfa hay so keep a close watch on those energy and protein RDI’s. Use grass/meadow hays in conjunction with alfalfa hay to fulfil a horse’s roughage requirement and well chosen supplements to fulfil mineral requirements. This will help you balance the diet and avoid some of the problems that can be associated with over‐feeding alfalfa hay.

Meet The Author: Dr Nerida McGilchrist

Dr Nerida McGilchrist is FeedXL’s co-founder and equine nutrition specialist. She holds a degree in Rural Science, a doctorate degree in equine nutrition and nearly 20 years of full time, on the ground experience in feeding all types of horses. To learn more about Nerida and to ‘meet’ the rest of the FeedXL team, check out our About Us page here.



Do you have a question or comment? Do you need help with feeding?

We would love to welcome you to our FeedXL Horse Nutrition Facebook Group. Ask questions and have them answered by PhD and Masters qualified equine nutritionists and spend time with like-minded horse owners. It’s free!

Click here to join the FeedXL Horse Nutrition Facebook Group


Complete Feeds vs Balancer Pellets: Choosing a Feeding Method

Complete Feeds, Concentrates/Balancer Pellets and Supplements—Choosing how to feed

While there are many commercial feed and supplement options available, they can be classified into 3 broad categories; complete feeds, concentrates/balancer pellets and supplements. Depending on your own personal preferences you can use one or a combination of these options to put together a diet for your horse.

This article will take a look at what the 3 options are, how they should be used and the advantages and disadvantages of each one.

Complete Feeds

A complete feed is a feed that has been formulated to meet the energy, protein, vitamin and mineral requirements of horses. They can be in the form of pellets, cubes, meal or sweetfeeds. Each complete feed will be formulated specifically for a certain type of horse. For example there are complete feeds for breeding horses, horses in sales preparation, pleasure horses, horses in hard work, horses that tie‐up … the list can go on and on.

Complete feeds will contain a variety of ingredients which are usually some combination of grains and grain byproduct (wheat, barley, corn, oats, bran, pollard), legumes or oilseeds (soybean, faba bean, lupins and other protein meals like cottonseed), minerals like salt, limestone and dicalcium phosphate as well as a trace‐mineral and vitamin premix. Many also contain oil.

For a complete feed to actually be “complete” when you use it in your horse’s diet, you must follow the manufacturer’s feeding recommendations for the feed. For example, a working horse feed will have a table on the bag that will say something like for a 500 kg horse in moderate work, you should feed 3 – 4 kg/day. If you feed less than this amount, your horse’s diet will not contain the required levels of vitamins and minerals and the feed will no longer be complete.

A common problem people find with complete feeds is that these feeding rates are too high, with many owners exclaiming their horse would explode if it was fed that much. If this is the case, the complete feed may need to be “topped up” with an appropriate supplement. Using this approach allows you to control your horse’s calorie intake, without compromising vitamin and mineral intakes. Alternatively, if the feeding rates of complete feeds are always too high for your horse, consider using either a concentrate/balancer pellet or supplement.

Complete feeds also don’t allow much flexibility in a feeding program, because deviating from the recommended feeding rates will mean you also unbalance your horse’s diet, so horses needing constant adjustment of their diet according to daily workload, bodyweight and temperament aren’t well suited to a complete feed.

Keep in mind that not all “complete feeds” are created equally. Some will do a very good job of meeting requirements when fed at the correct rates, while others will still leave many deficiencies in your horse’s diet, even when being fed at the recommended levels. This is where FeedXL is a big help—it allows you to easily see which complete feeds really are complete and which aren’t.

A diet for a working horse using a complete feed might look like this:

3.5 kg/day of complete feed
Plus chaff, hay and/or pasture

Concentrates and Balancer Pellets

Concentrates and balancer pellets are fed to meet a horse’s vitamins and mineral requirements, but unlike complete feeds, they only meet part of a horse’s energy and protein requirement. They can be in the form of pellets or sweetfeeds and have a feeding rate of between 0.5 kg and 2.5 kg/day. Concentrates and Balancer Pellets are designed to be fed in conjunction with other protein and energy sources like grains, legumes and oilseeds. They can also be fed alone when the horse has access to good quality pasture or is an easy keeper that doesn’t need the additional calories or protein.

The major advantage of a concentrate or balancer pellet over a complete feed is that it allows you more flexibility within your feeding program. Once you find the required rate of concentrate or pellet your horse needs to meet vitamin and mineral requirements you can then customise the rest of the diet to suit your horse’s tastes and your budget. They also allow you to adjust the amount of calories or protein you feed according to your horse’s workload, weight or temperament without affecting vitamin and mineral intake.

A diet for a working horse using a concentrate or balancer pellet might look like this:

1 kg/day of Balancer Pellet
0.5 kg/day Lupins
2 kg/day Oats
Plus chaff, hay and/or pasture

The major disadvantage of feeding in this manner is the time it takes to mix the feed. Vitamin and Mineral Supplements Supplements are fed to meet a horse’s vitamin and mineral requirements and do not contain any appreciable amounts of energy or protein. They have a feeding rate of up to 0.5 kg/day, with most supplements only fed at rates of 20 to 100 g/day, depending on the brand.


Supplements are designed to be fed with grains, legumes and oilseeds, when needed, to make up a complete diet for horses. They may also be fed alone (mixed with a small amount of chaff or some other tasty base so the horses will eat them) to easy keepers when only vitamins and minerals need adding to the diet.

Supplements are also commonly fed with a “complete feed” when the complete feed is being fed at less than the recommended rates to make up any shortfalls in vitamin and mineral intake that may be present.

A diet for a working horse using a concentrate or balancer pellet might look like this:

100 g/day of Vitamin and Mineral Supplement
0.5 kg/day Lupins
1 kg/day Extruded Barley
2 kg/day Oats
35 g/day Salt
Plus chaff, hay and/or pasture

The major advantage of using a supplement‐based diet is the amount of flexibility you have in creating the diet, both from the horse’s perspective and your budget. The major disadvantage is again, the time it takes to source the ingredients and mix up the feeds.

As for other commercial products, not all supplements are created equally. Some will do a very good job of meeting a horse’s requirements while others will do a mediocre job at best. Again, this is where FeedXL can be a big help in working out which do and which do not meet a horse’s requirements. When choosing a supplement, also be conscious of how much they are costing per dose (don’t look at the cost per pound/kilogram).


Depending on your horse and your own personal preferences you will prefer to feed either with complete feeds, concentrates/balancer pellets or supplements.

Complete feeds are simple to feed, provide good variety in the diet and are readily available. However they give you very little flexibility in how much you can feed, as not staying within recommended feeding rates will mean some of your horse’s requirements may not be met.

Concentrates/balancer pellets and supplements give you more flexibility, can be fed alone to easy keepers and allow you to customise your feeding program according to your horse’s tastes and your budget. However, they can make the time taken to mix feed longer and you will often have to source more ingredients.

Regardless of the feeding or mixing method you choose, always balance your horse’s diets. Weigh your horse to get the feeding rates right and so that FeedXL can correctly estimate your horse’s requirements. Only in this way can you be sure that the complete feed, balancer or supplements you choose are working correctly for you and your horse.

Meet The Author: Dr Nerida McGilchrist

Dr Nerida McGilchrist is FeedXL’s co-founder and equine nutrition specialist. She holds a degree in Rural Science, a doctorate degree in equine nutrition and nearly 20 years of full time, on the ground experience in feeding all types of horses. To learn more about Nerida and to ‘meet’ the rest of the FeedXL team, check out our About Us page here.



Do you have a question or comment? Do you need help with feeding?

We would love to welcome you to our FeedXL Horse Nutrition Facebook Group. Ask questions and have them answered by PhD and Masters qualified equine nutritionists and spend time with like-minded horse owners. It’s free!

Click here to join the FeedXL Horse Nutrition Facebook Group


Biotin: Should You Supplement?

Biotin is a vitamin essential for many functions in a horse’s body, including: fatty acid synthesis, protein and energy metabolism and cell proliferation.

In equine nutrition biotin is best known and most commonly used to positively influence hoof quality. There are many biotin supplements available. Some contain only biotin, others also have nutrients like methionine and organic zinc. These supplements are marketed as hoof supplements and the one thing they usually have in common is they are expensive. The question is, does your horse actually need supplemental biotin?

Biotin is naturally available to your horse

Your horse has access to two sources of natural biotin. Biotin is contained in most feeds and forages, particularly green fresh forages. In addition, the bacteria in a healthy horse’s gut produce biotin which is made available to the horse.

Therefore a horse on a forage based diet with a healthy gut should not need to be supplemented with biotin. BUT there are plenty of horses on this type of diet with poor quality hooves. Often horse owners turn straight to biotin in this situation to improve hoof quality. However, it is unlikely a biotin deficiency is causing the problem, which means biotin certainly isn’t going to fix it.

An unbalanced diet causes poor quality hooves

While supplementing with biotin may seem a good solution to improve hoof quality, it won’t help if the rest of the diet is unbalanced. Minerals like copper and zinc and good quality protein all need to be in the horse’s diet in balanced quantities for the horse to grow quality hoof.

The best way to achieve good quality hooves

Feed a completely balanced diet! If your horse has poor quality hooves it is likely its diet is missing something and it probably isn’t biotin. Steps to achieving good quality hooves are:

  1. Balance your horse’s diet using FeedXL and feed that balanced diet. It will be 3 to 6 months before you see a positive effect.
  2. Base your horse’s diet as much as possible on good quality forage.
  3. Avoid feeding uncooked grains (with the exception of oats) as these can upset the bacteria balance in the hindgut and reduce their natural production of biotin.

When should you use biotin?

There are some situations that may warrant biotin supplementation. These are:

  1. If your horse has been maintained on a high grain diet for an extended period of time.
  2. If your horse has been on a long term dose of oral antibiotic.
  3. If your horse is old and has lost some function in its hindgut.
  4. If your horse is recovering from a condition like laminitis or an injury that has affected its hooves
  5. If your horse has been on a long-term balanced diet and you are still not happy with the condition of his hooves, biotin may help!

If any of these situations apply to your horse and its hoof quality is poor despite a balanced diet it is possible that it is not receiving enough biotin. FeedXL will work out the best dose for your horse so that supplementing is effective. As a guide, a 500 kg (1100 lb) horse will need 20 mg of biotin per day and you will need to supplement for around 6 months for it to really work.

Meet The Author: Dr Nerida McGilchrist

Dr Nerida McGilchrist is FeedXL’s resident equine nutrition specialist. With a degree in Rural Science, a doctorate degree in equine nutrition and nearly 20 years of full time, on the ground experience in feeding all types of horses Nerida is able to help FeedXL members solve any problem they may come up against with feeding their horses. To learn more about Nerida and to ‘meet’ the rest of the FeedXL team, check out our About Us page here.


Do you have a question or comment? Do you need help with feeding?

We would love to welcome you to our FeedXL Horse Nutrition Facebook Group. Ask questions and have them answered by PhD and Masters qualified equine nutritionists and spend time with like-minded horse owners. It’s free!

Click here to join the FeedXL Horse Nutrition Facebook Group


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