Nutrition // Category

Category based archive
08 May

Now all the mathematics is out of the way and you feel you can compare each product and the nutrient’s they contain  we need to move on and consider the composition and balance of nutrients in the product.


Metabolism is quite complex, requiring a broad range of essential nutrients to function optimally.  You can’t just feed two or three nutrients and hope to support performance, recovery, health, and metabolism.  A lot of one nutrient doesn’t make up for deficiencies in another.  If you ran out of food in your house and tried to just live on a big bag of salt, you wouldn’t last long.


The balance between nutrients is equally important.  Some nutrients are required for the uptake and function of other nutrients. (These supportive and cooperative nutrients are called co-factors.) Too much or too little of one nutrient may result in deficiencies or toxicities of other nutrients.  Imbalances, therefore, can adversely affect health, performance, and recovery. At a minimum, imbalances in a feed or supplement can render a product ineffective.

For instance, vitamin C is required for the absorption of iron from the gut.  Without vitamin C, iron passes straight through the gut and out in the faeces.  Vitamin E, on the other hand, has a negative interaction with iron.  It binds with iron and reduces its absorption, causing much of it to be wasted. So, in order for horses to use dietary iron effectively, it must be administered with vitamin C and without vitamin E.  Iron balance is also closely related to Zinc, Manganese, Cobalt, and Copper.

Common Feed Ratios


B vitamins are known to work better when administered in optimal balance with each other.  They act in concert in many metabolic pathways important in energy production, red blood cell production, coat and skin condition, nerve cell function, and appetite.  Giving a bigger dose of one B vitamin may not produce improvements in health or performance if the entire range of B vitamins is not supplied in optimal balance.

Amino acids are another good example of how nutrient balance is important.  That is a topic I will discuss further in a later blurb about evaluating feeds, but in the meanwhile, read the article written by Dr. J. Stewart that we posted on our blog about top-line.  In that article, she explained, really well, how the balance of amino acids in a feed is as important as the amount of protein.  Imbalances in amino acids limit the amount of protein in a feed that is usable in the horse to produce proteins and muscle cells and waste products create a load on kidneys, elevated body temperature, and elevated heart rates.


Bioavailability refers to how absorbable and usable nutrients are.  While this is partly related to the composition and balance of nutrients in a product, the term is most frequently applied to the form each nutrient is provided in.

Some forms are more easily absorbed and used than others.  The trace element Chromium, for example, exists in several different forms.  The form of chromium found in a chrome bumper on a car is not very digestible at all, but the form incorporated into yeasts is very easily absorbed and then used by cells.  Minerals including Calcium, Magnesium, Iron, Cobalt, Copper, Zinc, Selenium, and Manganese can all be provided in a variety of forms, each of which have differences in their bioavailability.  In general, inorganic forms of nutrients are less well used than organic forms, though that is not always a reliable rule.  Zinc Oxide is one of the most bioavailable forms of Zinc, whereas Zinc Chelate forms a big molecule that remains quite inert.  In most cases, though, minerals provided as gluconates, lactates, and amino acid or protein complexes are well used.

When reading labels, you should note whether the amount of the ingredient or the amount of the active molecule is listed.  For instance, Iron Bioplex (iron is bound to amino acids or protein) contains only about 10% iron.   If a label says a product contains 400mg of iron per dose, that would mean that a dose contains about 4000mg of Iron Bioplex yielding 400mg of very well absorbed and used iron.  If the label says a product contains 400mg of Iron Bioplex per dose, then it really only has 40mg of iron.  Make sure that you read those details carefully when reading labels and comparing products.

So that’s part 2 done!

To recap Reading Labels – Parts 1 and 2 on Supplements

If labels are easy to understand so that you can tell, at a glance, what you are giving your horse, then the manufacturer is probably proud of their formulation and believe it will stand up to scrutiny. If you have to perform too many calculations to figure out what you are giving, there is a fair chance that the formulation isn’t great. In any case, take the time to do the math and make sure you are comparing apples before picking the cheapest or prettiest product on the shelf.

When reading labels, it is important to consider all aspects of the nutrient composition, including balance, form, and dose, in relation to the nutrient requirements of your horse.

Make sure you read the third installment of this Reading Labels Blog Reading Labels Part 3 – Product Quality Management this looks at the quality of ingredients and manufacture.

08 May

After working on this for more than an hour and barely scratching the surface, I suddenly realized that this will end up a very long (and boring) blog entry, indeed, so maybe I’ll try to do this in a series of smaller bite-sized chunks.  For now, I’m going to start with supplements. I think they will be easier to sort out.  If you want to know more about feeds, keep checking back.  I’ll eventually finish this…I hope.)

With the tremendous range of feeds and supplements available, how do you even begin to select the right ones for the horses in your stable?

Do you mostly rely on testimonials from friends, feed merchants, or sales reps from the feed/supplement companies themselves?  If so, you are not alone. The most common questions I am asked, by the horsemen I meet, from all around the world, relate to comparing feeds or feed supplements.  I get a lot of, “hey doc, a rep from a supplement/feed company came the other day and told me about one of their products.  They said it was the best ever… but they all say that.  What do you think of it?  Should I feed it to my horses?”

If you have ever wanted to ask those questions, read on.  I’ll try to give you some tools to sort out the wheat from the chaff.  Just like the horsemen who ask me about new products they have come across, I can’t always answer those questions immediately.  I have to follow a process to objectively evaluate them.  I’ll get to that next.

To begin with, so you feel better about your state of confusion when looking at supplements, here is my experience with the same thing.  (…and keep in mind, I am a veterinarian, and I studied nutrition in university before starting veterinary school.)

Back in 1999-2000 or so, I started looking at oral pastes and powders as a practical, economical alternative to the more invasive and expensive pre-race treatments I used to give my patients.

(My “loaded amino acid jug” was a Duphalyte or Amino Plus with 30cc’s CaCo Copper, 10cc’s Hemo 15, and 10cc Hippiron, with or without vitamin B12 and vitamin C, given iv along with folic acid given im.  Some of my clients liked to have their horses tubed with electrolytes and given Co-Forta injections instead).

In order to find one, or a couple of pastes in combination, that I could recommend to my clients, I looked at lots of supplements…practically all that were available in 2000, in fact.

I found a huge number of products listing different combinations of nutrients that were;

  1. included in different forms (For example, Calcium could be provided as Calcium carbonate, Tri-calcium phosphate, or Calcium gluconate), and
  2. quantified with different units of measure (mg/kg, %, ppm, to name only a few).
  3. Then, they were to be given in different doses.

The most confusing paste I found listed contents in terms of parts per million (ppm), percentages, and mg/kg.  Then, the syringe was in pounds and the recommended dose in ounces. OMG!!!  Clear as mud!!!  What I was beginning to wonder, was that if some companies don’t actually want you to know how much or little of each nutrient is in their product.  Standing in the feed store, it was nearly impossible to do all of the mental gymnastics required to evaluate and compare the products available. So, I did what you must do if you want to fairly compare apples to apples rather than apples to oranges.

  •  I made a list of label information and recommended feeding rates.

Then, before I could really compare supplements, I had to go home with my lists of label information, sit down with a calculator or spread sheet (…and a wine…or a latte…), look up conversion factors, and look up nutrient requirements.

Here is a link to my basic spread sheet that you are welcome to copy rather than typing all the nutrients into your own.
(If you just fill in the quantities and units as well as the dosage found on the label, the spread sheet should calculate the contents per dose for you.  If you come across units not covered in my spread sheet, please read on and try and understand how to convert units yourself.  If the math is just too off-putting for you, contact us at Pro-Dosa, and we will be happy to do the conversions for you and add them to my spread sheet for everyone else’s benefit.)


  • Enter or write down the contents as listed on the label, including the units.

Are the quantities listed in micrograms (mcg or ug), milligrams (mg), grams (g), kilograms (kg), parts per million (ppm), percentages (%), international units (iu), or 1000-international units (kiu or IU)?  Are those quantities listed per kg, pound, or dose of the product in question?

Here’s an example.

In this example, Arginine is listed as 0.31%, Iron is 3500 ppm, Vitamin B12 is 1013mcg/lb, and Thiamine is 992mg/lb.  (…No, it doesn’t make much sense to me either…Yes, stop now and go get that glass of wine!)  Here’s where we will start to make some sense of this stuff.

You will need to convert all the units to milligrams per gram (mg/g) or whatever units you understand.  (In NZ, we use the metric system.)  I generally convert everything to mg/g, as I have entered the nutrient requirements into my spread sheet in milligrams (mg) (more on that later), and the dose of product you will give your horse will mostly be measured in grams (g).  You can use the conversion factors here or google each nutrient.

A percentage, as you know, is a number out of 100, so a percentage is the same as an amount in milligrams per 100 milligrams or the amount in grams per 100 grams or the amount in peaches per 100 peaches.  Make sense?  Then, there are 1000 milligrams (mg) per gram (g), so we have to multiply the amount per 100 mg by 10 to get the amount per gram.


OK, in this example, Arginine is listed as 0.31% so that means there is 0.31mg per 100 mg.  We multiply this by 10 to get 3.1mg of Arginine per gram of paste.

Parts per million (ppm), using the peach analogy, is the amount in peaches per 1 million peaches.  So that is the same as the amount in micrograms per gram.  There are 1000 micrograms (mcg) per 1 milligram, and there are 1000 milligrams in a gram, so there are 1 million micrograms in a gram.  Anything listed in ppm, therefore, can automatically written instead as mcg/g.  We, of course, are working towards having everything in mg/g, so divide the amount in ppm by 1000 to get the amount in mg/g.

In this example, the Iron is listed as 3500ppm.  That’s the same as 3500 mcg/g.  If we divide by 1000 to get mg/g, there is suddenly only 3.5mg/g.  That doesn’t sound like nearly as much.


Now, on to the vitamins in this example…

As we learned before, there are 1000 micrograms (mcg) per 1 milligram.  Divide the amount in micrograms by 1000 to convert to mg.  In this example, Vitamin B12 is actually 1.013mg/lb.  Easy!


Whoa!  Not so fast.  That’s 1.013 milligrams per pound.  Now I didn’t grow up with the imperial system, so I had to think about that one.  There are 2.2 pounds per kilogram, and there are 1000 grams in each kilogram.  First multiply by 2.2 to find out how many milligrams are in a kilogram (1.013 x 2.2 = 2.23mg per kilogram) and then divide by 1000 to find out how many mg are in a gram.  It turns out, there are 0.00223 mg/g.



OR……. MG/LB X 0.0022 = MG/G

Thiamine (Vitamin B1) is already in mg…thank you very much!! However, it is also listed per pound, so as we learned above, multiply by 2.2 and divide by 1000.  You can fill in Thiamine on your spreadsheet as 2.18mg/g.

You can then just repeat this process for everything listed on the label.

There are a few conversions that I haven’t included here.  International Units (iu) are frequently used as a unit of measure for vitamins, medications, hormones, and other biologically active substances.  These are different for every form of vitamin as they include a measurement of effectiveness or biological activity.   I have to look the conversion factors up every time I have to use them, and the best place to find them is on Google.   So you don’t have to, here are a few of the main ones.

Vitamin A (as Retinol)0.3 mcg300mg
Vitamin A (as Beta-carotene)3.6 mcg3600mg
Vitamin C50 mcg5000mg
Vitamin D0.025 mcg25mg
Vitamin E0.67 mcg670mg
  • Convert the contents per kg, L, g, oz, or pound to the content per dose.

If you have converted the contents to mg/g and the dose is in grams, just multiply your quantity in mg/g by the dose.  If you have converted to mg/kg, then multiply your quantity by the dose and divide by 1000.  (There are 1000 grams per kg).

We have already calculated the contents in mg per g, so we just have to work out how many grams are in our dose and multiply by that number.  In this example, there are 68 grams (1 full syringe) per dose.

Arginine = 3.1mg/g x 68 g = 210.8mg per dose syringe
Iron = 3.5mg/g x 68 g = 238 mg per dose syringe
Vitamin B12 = 0.00223mg/g x 68g = 0.152 mg per dose syringe
Vitamin B1 (Thiamine) = 2.18mg/g x 68g = 148.24mg per dose syringe

  • Write down the nutrient requirements for your particular horse, at the specific level of work and stress they are under. In my spread sheet, I have included the requirements for a 450 kg horse in intense work.  Those requirements will work fine for a Standardbred at 400-450 kg, a flat racehorse at 500-550 kg, or a sport horse at 550-600kg, but you can look up the precise requirements that pertain to your horse.  National Research Council (NRC) is the best resource, but you can check out our Blog, Google, nutrition books, or ask an expert (nutritionist, veterinarian, etc).
  • Compare the contents per dose that you calculated to the nutrient requirements you looked up just now.

Your average horse needs about 400mg Iron per day and there is 238mg in this dose.  That’s not bad.

Doses of thiamine required to support nerve cell function are 1000mg upwards, so the 148mg in this fall a bit short.

While that seems complicated, it is really the only way to do it.  If you do it a few times and get comfortable with converting units and doing the basic mathematics, and if you have some of the basic nutrient requirements committed to memory, then you can do a rough comparison in a feed store.

Quick and Dirty Method

Most commonly, companies based in countries that use the metric system list their contents in mg/kg.  Divide the contents by 1000 to get to mg/g and multiply by the dose.

For example, we will use a dose of 50g, As there are 1000 grams in a kilogram, then your 50mL dose has about 1/20th of the contents on the label (50/1000 is about 1/20th).  You can just divide the quantity on the label by 20 to get a rough idea of what is in a dose and then compare that to what you remember of the requirements.

If the label is more complicated, then I do the calculations for one nutrient and then figure out what to multiply or divide the label quantities by to get what is in a dose.  Then I apply that factor to all of the nutrients.  Easy!

In our example, nutrients listed as percentages can be multiplied by 680.  In your spread sheet, you can multiply the column of percentages by 680 and the results are half done.

In general, divide nutrients listed in ppm by 1000 and then multiply by the dose in grams.

In our example, the nutrients listed as ppm can be divided by 1000 and multiplied by 68…or just multiply by .068.  (68 divided by 1000).

The nutrients listed as mg/lb can be multiplied by the dose and 2.2 and then divided by 1000 or just multiplied by 0.15.

So the hard part is done.  You can now easily compare the quantities in any product with nutrient requirements and see for yourself if each product in questions measures up and which ones looks to be the best.  To really make a fair comparison, though, you will still have to learn something about what nutrients to look for and why they must be in optimal doses; neither too much nor too little.

Make sure you read Part 2 of our Reading Labels series to understand the importance of ensuring the supplement contains balance bioavailable nutrients.

08 May

Twenty years ago, stomach ulcers in horses were not a commonly reported problem and veterinary texts listed them only as an infrequent finding in sick foals. Today, they are reported to occur in anywhere between 60 and 90% of standardbred racehorses and 50 to 60% of show ponies, stabled yearlings, eventing and dressage horses. The only group of adult horses free of ulcers are those on pasture 24 hours a day.

Pastured horses have a very different diet to stabled horses – and diet has been shown to contribute to ulcers. Under natural conditions, horses graze for around 16 hours per day. The stomach has adapted to a constant intake of grass by constantly secreting acid (for around 45 minutes per hour). The acid is buffered by saliva, which is produced during chewing and has a very high content of bicarbonate and mucus. The number of chewing movements and the amount of saliva produced varies with the type of feed. One kilogram of hay requires over 3000 chewing movements and results in the production of over four litres of saliva. One kilogram of grain requires only one third as much chewing and yields only two litres of saliva. The sign of an acid stomach is chewing of bedding, wood etc – the chewing process stimulates the flow of saliva, which in turn lowers stomach acid levels and the horse feels more comfortable – a bit like chewing an antacid tablet.

Stabled horses spend an average of four hours a day eating – compared to 16 hours for pastured horses. When chewing time and hence saliva production are reduced, stomach acid levels rise, increasing the risk of ulcers. High acid levels are a result of modern feeding practices: the amount of roughage, feeding frequency and type of feed have profound effects on stomach acidity. If the stomach sits empty for a prolonged period, the acid is not buffered by the food and saliva and the stomach will empty less frequently, allowing the acid fluid to remain in contact with the lining.

When feed is eaten rapidly, less saliva is produced and the sudden flow of a large volume of feed into the stomach causes a rapid increase in acid secretion. Both grains and pelleted feeds have been associated with increased risk. High grain diets favour bacterial growth and fermentation in the stomach. There is an increase in the number of bacteria that produce lactic acid and gas. Acid secretion increases in response to pelleted feed because pellets are eaten rapidly. Both weanling and adult horses consume pellets faster than they eat traditional grain diets.

Simply changing from pasture to hay and confining a horse to a stall can cause ulcers. Because hay is drier and coarser than grass, it can damage the lining of the stomach. Soaking hay for 6 hours will soften it and also reduce dust and airborne particles that irritate the respiratory system. In addition, any alterations in intestinal function may also be associated with stomach ulcers.  Insufficient blood flow due to worms can cause death of gut lining cells, resulting in slowing ulcer healing.

The most reliable way to produce ulcers in a horse is to provide insufficient roughage or to fast them. Multiple studies have demonstrated that periods as short as 12 hours without feed can result in low grade stomach irritation. Even beginning an exercise program results in more acid secretion by the stomach – making the provision of adequate roughage even more critical for the standardbred entering training.

Phenylbutazone or other anti-inflammatory drugs can also cause ulcers. The risk increases with long term use but can occur even after a single high dose. Phenylbutazone (bute) especially has an extremely low margin of safety and should only be used under veterinary supervision. A high salt intake can irritate or worsen pre-existing ulcers. To avoid excessive irritation, ensure that electrolyte intake matches need and give the daily dose with food.

Signs of stomach ulcers include poor performance, loss of appetite, poor condition and mild colic.  With the exception of mild colic, these symptoms can also be found in horses with a developing lameness, subclinical tying-up, a gut upset, electrolyte imbalances, sand ingestion and enteroliths.  However, loss of appetite for grain, signs of mild pain after eating, teeth grinding, salivation and belching are characteristic signs of stomach ulcers. While horses with a nervous temperament are thought to be more prone to ulcers, it is more likely that discomfort from stomach ulcers makes horses agitated and restless.

Horses with severe ulcerations and clinical symptom require treatment for at least 3 weeks. Around 20% of horses do not respond in that time and may need a different pharmaceutical or a spell. Horses with ulcers have notoriously poor appetites and may not have been eating all their medication if it was in the feed.  If dosed with it, poor technique could also lead to loss of some medication.  There is also a widespread problem with horses being given inadequate doses or not being dosed frequently enough, in attempts to save on the cost.

As few as 3% of moderate to severe ulcers heal without treatment in horses kept under conditions that predispose to ulcers. The only treatment that is 100% effective is to turn the horse out on pasture. Bear in mind also that the combination of poor appetite and alterations in gut pH, have negative effects that drugs cannot correct and supportive therapies, such as probiotics, should be considered. Even with improved appetite and weight gain, there can be a persistent mild dehydration, which can respond to combined probiotic/amino acid/electrolyte. Gamma oryzanol has been shown experimentally to have a protective effect on ulcer formation in several species, particularly ulcers induced by stress or fasting.

For less severe symptoms, and after the initial drug treatment, there are far less expensive therapies for continued treatment and prevention. Good results have been obtained with probiotics, gamma oryzanol, fermentation products, yeasts and digestive enzymes. These actives can be very effective in improving appetite, correcting diarrhoea and promoting weight gain. Some horses with ulcer-like symptoms that do not respond to anti-ulcer supplements respond extremely well to probiotics. In addition, under the guidance of your veterinarian, consider a special worming program for immature worm stages and for tapeworms.

In addition, not all gut symptoms are caused by ulcers and it is essential to have a veterinary assessment to rule out other causes of reduced appetite, weight loss and discomfort. Following a clinical and/or endoscopic examination, the various ulcer treatment options can be assessed.  Because of the major drawbacks of treatment –  cost, contravention of the Rules of Racing and recurrence of ulcers once treatment stops – long-term prevention with gamma oryzanol or another protectant, is advisable. Preventatives and treatments include good quality aloe vera juice, chlorophyll, gelatin kaolin, apple pectin, aluminum and calcium-based antacids, however, long-term use of compounds containing aluminium has been associated with toxicity.

The following feeding management practices can reduce the risk of ulcer formation:

  • Avoid prolonged periods of fasting – ulcers have been shown to develop within 10-12 hours when horses have no access to feed – ensure roughage available at all times
  • Feed on the ground – horses chew and swallow more efficiently when their heads are down and the throat extended. Feeding above the ground also results in abnormal movement of the lower jaw and unnatural patterns of chewing and teeth wear.
  • Feed frequent small meals – optimum is 4 times a day and not more than 2 kg of grain per feed.
  • Use steam-extruded grains and feeds which have been processed in such a way that eating is slower, resulting in more chewing, increased saliva production and higher saliva bicarbonate levels.
  • Deworm regularly with the correct compound.
  • Include probiotics and protectants such as gamma oryzanol in the daily diet.

By Dr. Jenny Stewart  BVSc BSc PhD MRCVS
Equine veterinarian and Consultant Nutritionist

08 May

Urinary Cobalt Excretion in Horses Supplemented with 1 mg Cobalt in Addition to Normal Dietary Levels


Cobalt is a trace element, required by horses in tiny amounts. It is necessary for vitamin B12 synthesis, and as a result, is a key nutrient affecting several aspects of energy production, metabolism, appetite, and health.  Along with copper, iron, B-vitamins, and other cofactors, it is involved in red blood cell production.   Cobalt is naturally occurring in feeds, in quantities reflective of the soils in which they are grown.  NRC 2011 lists several regions with soils known to be deficient in cobalt, including New Zealand and Australia.

National Research Council (NRC) is an organization that compiles and publishes the internationally recognized standards for nutritional requirements for most species, in various stages of life, environmental conditions, and levels of work. NRC 2007 standards indicate that horses in hard work or under stress require at least 0.1mg of cobalt per kilogram of dry matter intake. Your average 500kg racehorse can be expected to eat 2% of their body weight per day, which would be 10kg of feed on a dry matter basis. 10kg dry matter intake X 0.1mg cobalt required per kg dry matter = 1mg of cobalt required per day for normal health. According to NRC, resting horses require about half of that.  NRC 2011 standards list reduced minimum requirements, ranging from 0.5mg to 0.6mg, depending on age and level of work.

Cobalt has become a very significant issue in racing over the past year or so. Following positive tests in Australia, racing authorities have made cautionary statements about the administration of cobalt to horses, and it has been reasonably well publicized that administering it at levels that result in the excretion of more than 100-200 micrograms of cobalt per litre of urine (depending on the racing jurisdiction) will result in a positive test. What hasn’t been explained is how much cobalt you can safely feed before those levels are reached. Racing jurisdictions have been working towards finding that threshold but have not yet released any information.

On a more basic level, horsemen and veterinarians have been provided with very limited information about the impact of “normal” levels of cobalt in the feed on the cobalt levels in urine. “Normal” levels may be significantly less than the threshold doses that will eventually be established. Instead, regulatory authorities have said that cobalt deficiencies are not common in horses, and they have recommended that it should be eliminated, as much as possible, from the equine diet until data is published indicating the maximum amount that can be fed.

In general, feed companies use NRC guidelines when developing formulations, so most complete feeds will contain at least 1mg of cobalt per day, when fed as directed. Many racing stables, however, feed simple diets, comprised of unimproved pasture, home-grown hay, haylage, and chaff, supplemented with oats or barley. It is often necessary to top-dress these rations with broad-spectrum vitamin and mineral supplements to ensure that all nutrient requirements are met.  Based on the cautionary statements issued by some racing authorities about feeding cobalt, horsemen are now unsure if it is safe to continue feeding their usual preparations. Withholding all nutritional supplements, however, may not be the best approach, as far as equine health and welfare are concerned.  Some diets will almost certainly be left deficient in at least some vitamins and minerals.

Pro-Dosa BOOST is a complete, balanced, bioavailable multi-nutrient paste, developed to replace nutrients lost in hard work or required in greater doses when horses are under stress as a result of travel, racing, competition, or illness. Nutrients are provided in doses that directly reflect NRC requirements, so Pro-Dosa BOOST contains 1mg of cobalt. It is generally only used once or twice a week, on days in which horses are under greater stress, and is not a daily supplement. It has been widely used in racehorses and competitive horses of all types in 35 countries for the past 14 years. It has undergone in vivo clearance testing numerous times across Australasia and has previously been fed extensively in those markets, right up until race day, without incident. Currently, Pro-Dosa International Ltd fields weekly enquiries about the safety of feeding Pro-Dosa BOOST and/or normal rations to racehorses.


While the industry awaits peer-reviewed research to be published by regulatory agencies regarding maximum amounts of cobalt that can be fed on a daily or weekly basis without producing a positive test, we wanted to be able to answer questions about the cobalt levels in urine after feeding small amounts of cobalt, that are simply reflective of accepted requirements.

The purpose of our study was to measure the amount of cobalt excreted in the urine of horses in race training, fed a combination of typical, prepared feeds and home-grown forages, and then to quantify the increase in the amount of cobalt excreted in urine following the administration of an additional 1mg cobalt (provided as cobalt sulphate in Pro-Dosa BOOST) a very bioavailable form of the trace mineral.

Project and Study Design

We have conducted a fairly short, practical study of urine cobalt levels in horses given a small quantity (1mg) of cobalt sulphate, a dose that reflects the nutrient requirements of a horse in hard work as published by NRC (National Research Council) in 2007.

Specifically, the following are the steps we followed:

On day 1, we fed a group of horses a standardized diet in which cobalt content was measured, and then we collected a baseline sample of urine in which cobalt was also measured. (Sample 1)

A single syringe of Pro-Dosa BOOST, made without any cobalt, was administered to each horse (2), and urine samples were collected over 36 hours, at intervals reflecting label directions and typical race day schedules.  These were again analyzed for cobalt. This first treatment represented the negative control treatment. (Samples 3-7)

On day 3, a single syringe of Pro-Dosa BOOST containing 1mg of cobalt (as it normally does) was fed to each horse (8). Urine samples were collected at the same intervals for a further 36 hours, and these were also analyzed for cobalt. (Samples 9-13)

See Figure 1 for the proposed study design.

Planned Treatment and Sample Schedule
Figure 1:  Planned Treatment and Sample Schedule


An “hypothesis” is what is expected to occur.  Since NRC recommends the daily administration of 1mg cobalt, we expected that 1mg of cobalt would be cleared within 24 hours, and since NRC suggests that horses actually require that much cobalt, we might have expected that no waste cobalt would be excreted at all when 1mg was fed. As the standardized diet, however, was understood to contain some cobalt, we actually expected (or hypothesized) that the administration of an additional 1mg, might produce a small increase in the amount of cobalt excreted.


Feed analysis was conducted at Hill Laboratories, an accredited feed testing facility.  Results indicated that the basic feed items including chaff, haylage, and barley did not, on their own, contain enough cobalt to meet requirements as set out by NRC.  Two of the prepared feeds appeared to.   Cobalt content in each feed constituent ranged from 0.009 mg/kg to 1.667 mg/kg on an as fed basis.  (See Figure 2) A complete feed analysis is available if requested.

Treatments were given and samples were collected close to the planned schedule.  Urine cobalt analyses were performed by Eurofins, Wellington, a laboratory accredited for that test.  They are not a racing laboratory, however.

While the trends appeared to be quite consistent, there was some individual variation between horses, with one horse excreting double the cobalt compared to the other two at baseline.  (See Figures 3 & 4)  The horses were all of similar size, ranging from 425-450kg, and one of the two larger horses had the higher cobalt excretion values.

Results indicated a slight reduction in urinary cobalt following the administration of the portion of Pro-Dosa BOOST containing no cobalt (the negative control), and in two of the horses, that reduction was to a level below detectable limits.  The reduction in cobalt concentration in urine occurred between 4 hours and 12 hours, with levels staying low until some time after 20 hours.  By 28 hours after feeding Pro-Dosa BOOST without cobalt, cobalt excretion had returned to levels close to baseline.

After feeding the portion of Pro-Dosa BOOST with 1mg of cobalt, urinary excretion of cobalt remained essentially unchanged from baseline.  Statistical analyses performed by the University of Auckland, Department of Statistics, demonstrated no statistical significance of the very slight increases in two horses or the slight decrease the other.

To get a perspective on the amount of cobalt excreted after feeding a basic, un-supplemented ration and the additional effect of feeding 1mg of cobalt in comparison to threshold levels that would produce a positive drug test, see Figure 5.

Figure 5:  Urinary Cobalt Excretion in this Study Compared with Industry Thresholds 

Discussion and Conclusion

It is important to understand that the number of horses used in this study was very small.  A larger number of horses and a larger number of samples would be needed to draw statistically significant conclusions.  Until this study was completed, we did not know what sort of data we might get, if any at all, and the cost was quite high. We had intended to repeat the study in a second and third stable, but only after looking at preliminary data.  Unfortunately, it was more difficult to collect the samples than expected.  After the first day or two of urinating in pots, the horses stopped cooperating, and the final sample could only be collected from one horse.  With no additional data to compare it to, that data was discarded.  Had the urine collection been easier, a second, larger group of horses could have been used to obtain more results.  As it stands, few stables would be likely to volunteer to participate in a follow up study, especially if they talked to the trainer and staff who were involved in this one.

It was originally planned that blood samples would be taken in addition to urine, but that had to be abandoned as no laboratory that was accredited to do cobalt analysis in blood or serum was willing to participate. If a suitable laboratory can be identified, serum cobalt may be measured in a second study.  That would be easier, and I’m sure racing stables would happily participate.

Despite the limitations in our data set, the results were interesting, and we have achieved some of our goals.  We are now able to answer questions regarding the amount of cobalt excreted in urine compared to threshold levels, in a small group of horses in training, fed a diet, fairly typical of racing stables in the Auckland, New Zealand region.

In general, urinary cobalt was quite low compared to threshold levels, with our group averaging a baseline excretion of only 2.97 mcg/L while the threshold for drug testing has been set 67 times higher at 200 mcg/L in New Zealand and Australia. The study group of horses was eating 4.64mg of cobalt per day; with 3mg coming from one feed source, and only very small amounts coming from the forage and plain barley.  While this cannot be considered an indication of all basic feed stuffs, it is reasonable to assume that at least some un-supplemented rations, comprised of basic feed constituents, with no pre-mixed feeds included may be quite low in dietary cobalt.

Additionally, we established that feeding 1mg extra cobalt, provided as cobalt sulphate, did not significantly increase cobalt levels in urine.  Our group demonstrated a very slight reduction over 12 hours with a return to baseline levels or just slightly above by 20-28 hours.  This change was not statistically different from baseline, though.

Finally, the negative control samples showed some interesting trends.  The reduction in cobalt clearance was small, but very consistent.  It occurred between 4 and 12 hours and lasted for 20 hours.  This reduction could have resulted from increased water consumption and increased urine output, thereby reducing the concentration of cobalt. Urine output was not measured in this study, however, and nor was water consumption.  Both would be useful and may be examined in subsequent studies.

The second possible explanation is that, by feeding Pro-Dosa BOOST, which provides a broad range of elements required for metabolism, energy, and red blood cell production, the utilization of existing dietary cobalt was improved, leaving less to be excreted as waste.  In either case, the implications for health, performance, and recovery are positive.


We are now confident that feeding Pro-Dosa BOOST according to directions will not contribute to increased levels of urinary cobalt excretion.

We are comfortable that the levels of urinary cobalt excretion found in our study are much less than that which would place horses at risk for a positive drug test.

Our negative control part of the study demonstrated that Pro-Dosa BOOST reduced cobalt concentrations in urine, and that was likely due to one of the two following effects:

  1. Pro-Dosa BOOST increased water consumption, improved hydration, and increased urine output.
  2. Pro-Dosa BOOST improved cobalt utilization from the diet, reducing the amount that was excreted, unused, as waste.

If a racing laboratory can be found who is willing to do analyses on blood or who might do urine assays at a more competitive price, and if horsemen volunteer to participate, additional studies could be completed.  These would provide more confidence in the results and give trainers reassurance that feeding rations and supplements that are adequate to meet nutritional requirements will be safe when presenting horses at the races.

Pro-Dosa Int’l would like to acknowledge Derek Balle Racing Stables, Pukekohe, New Zealand for participating in the study and for collecting all the samples. We really can’t thank you enough!

07 May

Protein features frequently in discussions on feeding, nutrition and performance. Alternately feared and revered, it is part of the bigger picture of conditioning/nutritional protocols that result in specific changes in body composition and performance.

The word protein comes from the Greek word ‘protos’, meaning ‘first’, because protein is the primary basic constituent of all living cells. It makes up 3/4 of the dry weight of most living cells and is involved in the formation of hormones, enzymes, antibodies and many other functions essential to life.

Protein is a collection of amino acids tied together. Once the protein is consumed and digested the amino acid chains breakdown into single amino acids. To appreciate how much the racehorse depends on receiving the correct amino acids in the diet, is to be aware of how dynamic the equine system is. Every second the bone marrow makes millions of red blood cells; every four days the blood platelets and most of the lining of the gastrointestinal tract are replaced; every 10 days, most of the white blood cells are replaced and the number of muscle cells repaired or created in horses that are training and racing is huge. In addition, necessary for muscle growth and repair, strong tendons, optimal energy metabolism, increasing bone density, joint health, hoof wall thickness and greater overall soundness is the interaction of vitamins and minerals with amino acids.

The horse requires a precise number and balance of amino acids. Essential amino acids cannot be synthesized by the horses system and are so-called, because it is essential that they receive them every day in the feed. The exclusion or a deficiency of even one essential amino acid from the diet will reduce total body protein synthesis. In horses where everyday maintenance is necessary and improvement with training is required, the creation of new cells is a priority. If just one amino acid in the profile is missing the creation of new cells stops.

Horses receive amino acids from the protein in both concentrates and hay. Every protein source has a different combination of amino acids. Some combinations are very good and some not so good. For this reason, the total protein of horse feed is a worthless term, unless you know the amino acid profile. For example, the feed tag might say 14% crude protein, but to the horse, if all the amino acids are not supplied, it may be only 8 or 9% usable protein. The more unusable protein the horse consumes the more he has to excrete. The feeding of unusable protein stresses the horse’s system. Excess protein can contribute to higher heart and respiratory rates, increased sweating and dehydration.

While some studies have concluded that the racing standardbred does not need additional protein, they do not take into account the quality of the protein. Poor quality protein in terms of amino acid profile, can contribute to the gradual weakening of supportive tissues, bone loss, muscle atrophy and the weakening of blood vessel walls that eventually lead to bleeding or breakdown. What is important is that the horse receives the amino acids that it needs in the correct amounts, readily digested and absorbed.

Over the centuries, horsemen and women have ground, cracked, crushed, boiled, dry-extruded and pelleted feeds for horses. They have done this to increase the digestibility of the feed and to decrease the risk of grain overload, a major player in colic, diarrhoea and laminitis. However, all amino acids have a different melting point and many of these older methods of grain processing result in damage to the amino acids and little improvement in digestibility. Soybeans and processed grain by products must go through some sort of heat process. This heat can destroy the most important essential amino acids. Feeds such as brewers grain are almost always heated at a very high temperature. This heat process destroys many valuable amino acids and makes the feed unbalanced, preventing the horse from getting the full value of the feed protein and taxing the liver and kidneys in excreting all the out of balance and, therefore, unusable amino acids.

The most recent advance in preparing feeds for horses is steam-extrusion. Whereas essential amino acid losses of up to 50% have been measured during dry-extrusion, losses during steam-extrusion are less than 5% and digestibility of the feed increases to over 90%. The application of steam-extrusion and the provision of high levels of essential amino acids in the correct balance are fundamental. Protein in general should never be fed in excess to any horse and neither should there be an overload of protein types that are poorly digested or that the horse cannot use. Essential amino acid deficiencies can occur even if diets containing excess protein and deficiencies cannot be corrected by feeding more of it, if it is not correctly profiled.

The second, separate issue is restoring protein balance after hard work or racing and encouraging the building of lean muscle mass. During hard training and racing, standardbreds damage muscle tissue as a result of the production of high levels of lactic acid and exertion. Muscle must be repaired rapidly to maintain improvement, prepare for the next training session and minimise delayed muscle soreness and stiffness. While in training or before and after racing, dietary programs must be chosen with care to facilitate quick recovery. Hard work causes a decrease in protein production that continues for a few hours after exercise has ceased. Protein in muscle is extensively broken down during exercise and this process serves a number of functions, but it is during recovery that the protein will be working hardest, repairing and building the rips and tears that occur during training.

No matter how balanced the diet is beforehand, exercise naturally causes a disruption. During exercise muscles use fuel at a very high rate and this is a catabolic process, i.e. it involves the breakdown and utilization of body reserves.  However, we are able to switch the catabolic environment into an anabolic (ie, a building of body tissues and reserves) environment after work by supplying the proper tools. Feeds chosen must contain protein that is profiled properly for amino acids, along with minerals, vitamins, fat and carbohydrates.

Nutrition is a powerful tool when used properly.  To the extent that we focus on the challenging bigger picture of conditioning/nutritional support protocol, the horse can harmonise the multiple systems necessary to reach genetic potential. High quality protein in terms of amino acid profile and availability is essential for maximum performance of the Standardbred racehorse.

07 May

Peak performance depends on the supply of energy to drive and fuel the working muscles. Providing almost three times as much energy as oats on a weight basis, oil offers many advantages in terms of energy efficiency. For both digestive and metabolic efficiency, oil is superior to grains and protein. In fact, the efficiency of ATP synthesis (i.e. the currency of energy), is around 39% for oil and 20% for carbohydrates.

In addition, calmness, as measured by spontaneous activity and reactivity (spook tests), is lower when diets are fortified with oil. Oil-enriched diets reduce the amount of metabolic heat generation, both at rest and during exercise and for the racing standardbred, this reduction in heat load can provide a competitive edge. The lower heat load lessens the need for sweating, reducing fluid loss during exercise. Studies have traditionally shown that oil-enriched diets affect working muscles by increasing oxygen uptake, increasing fatty acid utilization, sparing muscle glycogen during low intensity exercise and increasing glucose availability during intense sprinting exercise. Fat supplementation also reduces heat production, improves hydration and perhaps most importantly, improves the power : weight ratio.

Overdoing oil can result in decreased glycogen stores in the muscle, meaning the horse could “hit the wall” sooner, or have nothing left at the end. However, this does not happen until oil comprises more than 8-10% of the total diet – including hay, chaff and concentrate. So, for a 450kg horse eating 10kg of feed, oil intake would have to exceed 800-1000ml a day before there was any interference with muscle glycogen.

However, not all oils are created or utilized equally. Cold pressed oils are far healthier than solvent-extracted oils. Cold-pressed canola contains vitamin E, Coenzyme Q10, lipoic acid, omega-3 essential fatty acids and other very potent natural antioxidants. Without the addition of EPA and DHA, up to 10 times more oil is required to achieve the same levels of omega 3 activity, so for both ourselves and for hard-working horses, it is important to check that EPA and DHA are present in the oil. The maximum benefits from oil occur after two to three months, so it is best to introduce oil-enriched feeds and Omega 3 supplementation early in the program. This will allow sufficient time for metabolic adaptation to occur and ensure that the benefits of fat supplementation are realized when they are needed most.

The ratio of muscle to body fat affects the power to weight ratio – so when we want topline in a racing standardbred, we must use the combination of work and diet that will promote muscle building and not fat deposition. Just as occurs in humans, the finer details of the diet affect body composition. In addition to the type and intensity of exercise, the amount of muscle development is determined by the amino acid composition of the feed protein. Soybean meal, lupins and lucerne are well known as good sources of protein and this is because they are high in lysine.

Lysine and methionine are just two of the essential amino acids that make up protein. Just as branched chain amino acids have been found to be important in horses, on-going equine nutrition research has shown that other amino acids, including threonine are important for muscle building. Regardless of the percentage of protein in the feed, if there is not enough of each amino acid a limit will be put on muscle development and the horse will lay down cover (fat) instead of muscle.

But even if the feed contains good levels of lysine and other essential amino acids, for several reasons, they may not be available to the horse. Some feed processing techniques, such as dry-extrusion, rely on high temperatures and shearing forces which can damage lysine and other amino acids. Steam-extrusion includes moisture in the cooking process and losses are negligible and digestibility increases to over 90%.

As well as a sound daily nutrition program, strategic timing of meals pre- and post work can impact profoundly on the development of muscle power. Muscles consume vast amounts of anti-oxidants and essential amino acids during work and at the microscopic level, small strains, rips and tears occur. Correct composition and timing of feeding can take advantage of the window of opportunity created by the raised hormone levels and increased blood supply that accompany exercise. To be effective and hasten muscle recovery, the concentrate must provide anti-oxidants, amino acids and be consumed no more than two hours before or one hour after work.

The effectiveness of the diet is measured in terms of metabolic efficiency, i.e. the maximum output with the minimum production of undesirable products such as manure, acid and heat. To increase power for work, diets need to be designed to influence muscle fuel levels. But the feed chosen also influences the power : weight ratio (ratio of muscle to fat), thermoregulation (heat production and hydration) and mental attitude – all of which impact on performance and fatigue.

07 May

I thought I was finished.  I celebrated being finished, in fact… and then I thought about product quality management and security.

How do you know if the product you are looking at contains what is says it does; only a fraction of what it says it has; or way more than it is supposed to have?  And even more alarmingly, how do you know it doesn’t contain contaminants that aren’t supposed to be there?

There was an interesting study presented at the AAEP (American Associate of Equine Practitioners) several years ago in which several nutraceuticals were analysed and their actual contents were compared with label claims.  Those products were found to contain anywhere between 10 and 200% of the active ingredients that they were supposed to have.  Apparently, this is a more wide-spread problem then you would think/hope.  I posted a link to The Horse magazine article written about that study on our Facebook page a couple of years ago, and I think it’s well worth a read.  Read it here.

To bring that home for you, many people will have heard of the tragic, fatal cases of selenium toxicity that occurred a few years ago in a group of polo ponies fed a feed that was made with far too much selenium.  The manufacturer had simply made an error in calculations and had put a decimal in the wrong place, resulting in 10 or 100 times the selenium being added to a batch of feed.

In the racing industry at the moment, the trace-element, cobalt, required for health in small amounts, has been in the news lately. Excessive levels found in urine constitute a positive test, and several cobalt positives have recently been or are currently being investigated by racing authorities.  In some of the cases, injectable products were found to be at fault, but in one case, a powdered feed supplement which contained cobalt levels far in excess of label claims has been implicated.

We have done a cobalt clearance study that you might want to read, and we test, both, our raw ingredients and our finished product for cobalt to ensure that the exact dose listed on the label, not more or less, is what is in BOOST.

Almost everyone in racing will know of someone who has ended up with a caffeine positive as a result of feed contamination, and I believe there was a recent case in European equestrian circles in which a feed, contaminated with poppy seeds, resulted in a positive test and the disqualification of a prominent horse and competitor.

So, how do you know if a product is manufactured safely and meets label claims?

This information isn’t generally on the label, but it can be just as important as the label itself.  To get it, you either have to know the company management personally and have confidence in their diligence and ethic; you have to actually talk to the manufacturer and ask questions; or you can look at their website to find a statement about quality management or evidence of third party certification of their quality management practices.

Tip: Be sure to ask every rep that visits your stable about quality management as they will almost certainly be the most readily available source for this information. That will also be a simple way to separate the wheat from the chaff. Any rep that can’t talk competently about their company’s quality management program probably represents a company that doesn’t have one.

Does the manufacturer have a quality management program?  GMP or ISO certification provides hard evidence of this.

GMP stands for Good Manufacturing Practice, and this is a specific standard required for pharmaceutical producers.  It is, however, voluntary for feed supplement manufacturers.  A generic version of good manufacturing practice, abbreviated with small “gmp”, is a reference to a quality management system that is not name-brand, government specified and inspected, GMP.  It could be the same as GMP or it could be applied to a non-standardised or less complete quality system.

Compliance with a name-brand GMP program ensures that quality is built into the product at the time of manufacture and provides assurance that products are consistently manufactured from quality inputs; in a safe and clean environment; by trained and diligent staff; using carefully defined procedures.  It is a means of giving consumers confidence that products meet the required quality standards, are safe, and are reliable.  A documentation trail that links starting materials, through the various manufacturing processes, to the finished product confirms that dispatched product has been approved through quality control measures.  It also ensures that product can be tracked and recalled if any issues arise.

ISO9001/22000 refer to slightly different quality management standards that do not relate directly to pharmaceutical production but that cover many of the same principles.  They demonstrate a commitment by management to food safety, and they ensure that consideration of potential hazards and critical processes have been considered in the development of the product and production procedures.

If a company has either ISO or GMP certification, you can be sure that the supplements they produce will be safe, secure, and generally meet label claims.

If a manufacturer lacks certification, it doesn’t mean they aren’t doing a fabulous job of quality management.  They might have a written statement about their commitment to quality management or you might have to ask some questions to be sure.  If at least some proportion of finished product undergoes analysis for common contaminants, the concentration of active ingredients, and microbial testing, it will likely be safe.  If no testing is done, and the company doesn’t talk about product quality, safety, and security, I’d worry.

FYI, Pro-Dosa International Ltd. is GMP certified by the Government of New Zealand, Ministry for Primary Industries, Agricultural Compounds and Veterinary Medicines group.  Our quality management system has been in place since 2005, and it was originally developed along GMP, ISO22000, and ISO9001 standards.  The whole team is very proud of our standards, and we would be happy to tell you all about what we do, if you really want to know.

Make sure you read the final installment in this series of blog posts on Reading Feed Labels.  This article discusses the requirements in regards to nutrient composition of horse feeds. Part 4 -Horse Feed Requirements

07 May

Now that you have supplements sorted out, what about feeds?  Comparing prepared feeds is just about as confusing as comparing supplements, but with less math, you’ll be pleased to know.

Somehow, until the mid-2000’s, I managed to go through life blissfully unaware of the complexities of choosing prepared feeds.  I worked in racing stables, and all my clients fed a prepared racing formulation to their racehorses, and though some added bits and bobs, such as barley, supplements, and oils, they didn’t really ask me that many questions about their basic feeding regimens.  Then, I set up a mobile equine veterinary practice in Al Wathba, Abu Dhabi, UAE.  It was a pretty interesting place where I met a broad range of people, from nearly every background and nationality, with a wide range of horses, in a whole array of different management situations, doing every possible activity.  To add to the rich tapestry of experiences, I’d often find the entire equine and human smorgasbord at a single stable.

This complex set-up, the need for refrigerated feed rooms (Outside temperatures soar to 45-50 degrees Celsius, and inside it would be even hotter.  Nutrients aren’t very stable when they are heated excessively, and moulds etc. do really well.), and the ordering systems for some feeds meant that many of these stables had an entire pallet of feed, for each type of horse, in each activity.  This, of course, cost a fortune and took up way more space than anyone really had in their refrigerated feed rooms.  To top it all off, the forages available (…and there is no grass…ever), are variable in quality throughout the year.  Some had imported hays that were expensive but quite nice for at least part of the year, and some had the highly variable and often not very nutritious local hay.  This meant that feed costs and logistics were of major concern to virtually all of my clients.  They pretty much all asked me about the prepared feeds they were feeding and asked about simplifying the whole ordeal.  (They also asked me about the value of dates and camel’s milk in the equine diet which I looked into, being open minded and all.  I was a bit impressed with camel’s milk in particular and would quite like a dairy camel at home in NZ… I’ll tell you about what I found out sometime…but I digress…)

In order to answer all the questions about feeds I was getting, I took myself off to the camel souk (a market at the camel racetrack where, ironically, most horse products can be found) and had a look at the myriad feed stores.  There were feeds from every company I could think of, from every country in the world.  It would take a lifetime to sort through the entire selection, so I started by looking at the ranges of feeds from each of the brands that my clients were feeding.

I found an enormous number of feeds that looked pretty similar.  I had a hard time telling apart…

  1. the different formulations from the same company as well as
  2. the formulations from different companies, all of whom had similar feeds and ranges as the others.

The bags were different, but what was in them was pretty much the same. They all had very similar ingredients, in very similar, but not quite identical, proportions. I couldn’t really tell them apart, and I’m guessing, without referring to the names on the bag, like Racehorse Mix or Cool Feed, you would struggle to tell the difference too.

So before we begin sorting out how to compare different feeds, you should know some feed basics.

It is important to know something about the volume a horse will eat in a day.  Most horses will eat between 2-3% of their body weight per day in feed, including hay, grass, and concentrate feed.  When horses are working very hard, their feed consumption is generally at the bottom of the range, and for that reason, they can’t normally meet their protein and energy requirements by eating grass or hay.  A concentrated form of those nutrients must be fed.

Since a 500kg horse in hard work will only eat about 10 kg per day, all of the nutrients required must be fed in that volume of feed. It is also important to keep in mind that the larger part of the ration should be provided in the form of roughage as that is what keeps the gut moving properly and the flora healthy.  For this reason, you really can’t just feed a horse 10kg of a concentrated feed and nothing else.

So, before we begin to talk about feed, then, we have to talk a bit about hay and grass.  It is important to know something about the quality of your forage.  You can use average values for the nutrient content for each plant species to get a rough idea of what your hay or grass is contributing to your horses’ daily rations, but an analysis provides more accurate information.  You may be able to ask your feed supplier for an analysis of the hay they sell, or you may send samples of your pasture grass and hay to a laboratory yourself.  There are also packaged hay products available in most parts of the world.  These are labelled with nutritional information, just as concentrate feeds are, but there is one catch you may not be aware of.  Nutritional information can be listed on a “Dry Matter Basis” or on an “As Fed” Basis.  “As Fed” is pretty self-explanatory.  Nutrient content is measured in a kg of the forage in the form that you’d feed it.  When you feed 1 kg of it, you will be feeding the feed, moisture and all. “Dry Matter Basis” means that the nutrients are listed as a percentage of just the dry component of feed that is left when the moisture is removed. When you compare feeds, you will need to calculate the amount of nutrients on an “As Fed Basis”, as when you actually feed your horse, you will be feeding the feed, moisture and all.

For example, if a packaged forage lists their nutrient content on a Dry Matter Basis, but the moisture content is listed 50%, 1kg of that forage contains only 500g of dry matter and 500g water.  If the label says there is 20% protein on a dry matter basis that is the same as saying there is 200g of protein per kg of dry forage.  When you actually feed it to your horse, however, you will be feeding the forage along with an equal amount of moisture (water).  To get 1 kg of dry matter from that feed, therefore, you have to feed 2 kg.  If 1kg of the feed, on a dry matter basis has 200g of protein, when the 1kg of moisture is added back into the calculation, there is only 200g of protein in 2 kg of the feed as fed.  On an as fed basis therefore, the feed is only 10% protein or 100g of protein per kg of feed.  To convert from dry matter basis to as fed basis, multiply by the percentage moisture and divide by 100.

Content “as fed” = 20% protein on a DM Basis x 50% moisture/100%

With dry hays, the moisture content is less than 10%, so the “as fed” content is almost the same as the content on a dry matter basis.  Grass, in contrast, in about 90% water, so the as fed content is very different than the content on a dry matter basis.

Depending on the maturity and conditions at harvest as well as the type of hay, protein content can vary from well under 10% for poor grass hay up to 18-20% or so for nice Lucerne (alfalfa) hay, chaff, or cubes.  The poorer the hay being fed; the greater the importance of the hard feed.

Horses need energy, protein, calcium balanced with phosphorus, vitamins, and minerals including salt.  All horses need these same nutrients, but those working hard, growing, in foal, and lactating, need more of them.  You can find nutrient requirements for your specific horse by looking up NRC or by asking your feed supplier, nutritionist, or veterinarian.  I talk about some of the requirements later in this post.

When nutritionists balance rations, they start by looking at the protein and energy content (and costs) of the feed ingredients available. Then, once they have decided on the main components, they look at vitamins and minerals etc. which can be added and adjusted to achieve optimal balance while considering the contribution of the main components of the feed.  So, just as if we were formulating a new feed or ration, we will start with energy and protein.

The main differences between the varieties of commercial preparations include…

  1. The concentration of nutrients, especially energy and protein, and
  2. The specific form of energy and protein provided.

For example, spelling mixes have lower concentrations of energy and protein than racehorse mixes.

This is generally because most feeds are designed to be fed at a rate of 4-6 kg per day.  A spelling horse will need to eat 5kg of a spelling mix to meet its lower requirements for energy and protein, and a racehorse needs to eat 5kg of a racing mix to meet its needs.  In fact, if the spelling horse ate the racehorse mix, it could just eat less of it to get the required amount of nutrients.

Protein – Quantity

For this section, remember that there are 1000 grams (g) in 1 kilogram (kg).  I’m sorry, but I didn’t promise there wouldn’t be ANY math; just less of it.

Protein is often expressed as a percentage on feed bags, and horsemen tend to think of protein requirements in terms of those percentages.  (ie.  Racehorses need 16% protein and spelling horses need 10%.) In fact, protein requirements are in grams per day and not in percentage at all.

100g of protein could be found in 100g of a 100% protein feed; 1kg of a 10% protein feed; or 10 kg of a 1% protein feed.  So, the percentage of protein in a feed is only important when you consider how much of that feed your horse will eat.

Horses in hard work need about 1000-1500 g, particularly if they are also growing.

Spelling horses need about 750 g

Ponies (adult weight 200 kg) in hard work need 350-450 g

The average 2-3 year old racehorse in intense work needs 1000-1500g of quality protein per day.  As I already said, a horse in hard work will eat 2% of their body weight per day.  As a result, a racehorse could be expected to eat only about 5kg of concentrate feed and 5kg of roughage.  If the average protein content of hay is 13%, then about 650g of protein can be derived from hay.  The rest has to come from the concentrate feed.

A concentrate feed of at least 13% protein fed at a rate of 5 kg per day might be enough for the average horse, but some will need more like 850g of protein from their concentrate feed, and since that must be provided in 5kg or less feed, then the feed would have to be 17% protein to meet requirements.  If it was 20% protein, the 850g could be fed in 4kg of feed, and the 650 would be provided in 3kg.  That would allow that horse to eat a bit more hay, which has some benefits for the health of the gut.

Remember, don’t worry about the percentage of protein in the feed being high.  If the percentage of protein in the feed is high, you will simply be able to feed less of it to meet your horse’s protein requirements.

Protein Quality

In order for horses to make proteins (which are the building blocks of muscle cells), 10 essential amino acids must be provided in particular ratios. (Essential amino acids are those that horses cannot synthesise and, therefore, must consume.)  If even one of these essential amino acids is in short supply, protein production will stop. The amino acid, available in the lowest relative amount, is said to be the limiting amino acid.  The excess amino acids (the ones in higher amounts than the limiting amino acids, that now can’t be used for protein and muscle cell synthesis in the horse) become waste products, resulting in increases in heart rate and load on the kidneys.  For this reason, the best protein sources have the best essential amino acid balance, and as many of the amino acids provided as possible can be used for protein synthesis and muscle development in the horse.

Grains, like barley and oats, have some imbalances in the amino acid ratios, and as a result, only about 40% of the protein in an oat or barley-based feed will actually be useable by the horse to make muscle. In comparison, the ratio of essential amino acids in peas, lucerne (alfalfa), lupins, or soy allows for about 80-90% of the protein to be used.

Make sure you consider, therefore, the type of protein provided in a feed.


  • Horses in hard work need about 26-35 Mcal of DE (Digestible Energy)
  • Spelling horses need about 15-18 Mcal of DE
  • Ponies (200kg mature weight) in hard work need 11-14 Mcal of DE

Energy requirements can often be met by pasture or hay in spelling horses, but for horses in hard work, it is necessary to feed a concentrated feed in addition to forage.  Energy is provided in equine feeds in the form of carbohydrate (grains, corn, etc.) and as fat.  Traditionally, oats and barley were fed as the primary energy source.  They are a cost-effective way to provide energy, and some horses do very well on them.  Some individuals, however, do not.  Horses that suffer from a tendency to tie-up, those that have a tendency to founder, and those that colic are generally better avoiding grains.

Normal carbohydrate digestion starts in the small intestine.  Starch is broken down to complex sugars, and the complex sugars are, in turn, broken down to glucose.  Glucose is absorbed through the small intestine.  Any starch or sugars that aren’t digested and absorbed by the time the digesta leaves the small intestine are dumped into the cecum and large intestine.   That part of the gut, known as the hindgut, is a big fermentation vat. Bacteria in the hindgut work slowly on the digesta, breaking down roughage to molecules called volatile fatty acids that can be used by the horse for energy.

Horses’ guts, however, were never designed to process large amounts of starch, so the enzymes required for its digestion are produced in limited supply.  Grains are very high in starch and sugar and can, therefore, pose problems for digestion.  If large amounts are fed at one time, some starch and sugar pass undigested into the hindgut, making it’s environment more acidic.  The beneficial population of bacteria can’t survive in an acidic environment, and when they die, they release endotoxins.  Those endotoxins are responsible for problems such as colic, laminitis, and diarrhoea.  In addition, undesirable bacteria are able to thrive, further disrupting the cecal pH and worsening the environment for beneficial bacteria and so on.

While the rule of thumb is to limit grain feeding to 2kg at a single meal, some susceptible individuals will not even tolerate that quantity at once.

In comparison, fat is a reasonably safe source of energy.  While horses were not really designed to eat fat either, they do not seem to have problems with it.  Researchers have found that horses tolerate as much as 10% of their diet as fat.  For horses in hard work who may require quite a bit of extra energy in their concentrate feed, or for individuals prone to laminitis etc, look for a feed that has less grain and more fat.  It can take muscles cells 2-4 weeks to adapt to fat as an energy source, so if you are switching a racehorse to a high fat, low soluble carbohydrate diet (low grain), try to do it when they are not racing in a week.  Once metabolism adapts to fat, there is evidence of improved endurance, lower body temperatures, and a reduced incidence of tying-up, laminitis, and colic.

Vitamins, Trace Minerals, and Extras

Pasture and hay may not meet all of the vitamin and trace mineral requirements, even in spelling horses.  These nutrients, in most cases, will need to be supplemented, either on top of a plain feed, or in the form of a prepared feed.   I wrote about vitamin and mineral requirements as well as the need for balance between each of these elements in the first parts of this reading labels series, so I’ll just mention a few things here.

I generally prefer people to provide a prepared feed rather than mixing their own, unless they know a bit about nutrition or have had advice from a nutritionist.  It is easy to get the balance wrong and cause more problems than you fix.  Companies making feeds employ nutritionists and provide reasonably balanced preparations for you.  I would go so far as to say that all feed companies refer to nutrient requirement standards when formulating their products.  In reviewing the huge range of feeds available in the UAE and New Zealand, all I looked at appeared to meet the basic, daily requirements for fat soluble vitamins and trace elements when fed according to package directions.  Some provided those nutrients in more bioavailable forms than others (see part 2 of our reading labels post), and I would certainly choose the feeds that include more bioavailable forms of nutrients, but most would be pretty acceptable.

Calcium and Phosphorus must be provided in the diet of horses in a 1.5-2:1 ratio. Commercially prepared feeds will all be pretty well balanced in this department, so you won’t have to worry about this much.   In general, grains are high in phosphorus, while lucerne (alfalfa) is high in calcium. Be careful to get this right if you are mixing your own feeds or adding additional grains to prepared feeds.

I talked about most of the trace minerals in previous sections of this marathon post about reading labels, but I didn’t say much about selenium.  NRC says that horses in hard work require 1 mg per day, and most nutritionists would probably agree that 3mg is a better dosage to aim for in the diet.  The interesting thing about the requirements, is that horses really don’t have a requirement for elemental selenium (just plain, selenium).  Their requirement is actually for the selenium containing amino acids, seleno-methionine and seleno-cysteine.  This is important.

Selenium is described as having a “narrow therapeutic range”.  What that means is that the amount that is toxic for horses is not that much more than the amount they require for normal health.  This is also important to know.

Selenium can be provided in several forms.  It is provided in feeds as sodium selenite, sodium selenate, selenium yeast, seleno-methionine, and seleno-cysteine.   These forms have some fundamental differences.  They are not all absorbed, used, and excreted by animals to the same extent.  Selenium yeast is a form of selenium that is created when yeasts are grown in an environment with lots of selenium.  The yeasts incorporate the selenium into their own amino acids, so the selenium in selenium yeast is actually provided as seleno-methionine and seleno-cysteine for the most part.  So, you can consider the last three forms as essentially equal.  They are organic molecules that the body is good at absorbing and using.

The sodium selenite/selenate molecules, on the other hand, are inorganic salts that are unpredictably absorbed and used by animals.  Studies done about 20 years ago in dairy cows demonstrated that cows supplemented with the same, standard amounts of those forms of selenium in the same diets, ended up with very different levels of selenium in their blood.  Some were in the normal range, and some were deficient.  When the level of supplementation was increased to correct the deficiencies seen in part of the herd, others started to show signs of toxicity.  The conclusion was that the ability to absorb and use sodium selenate and sodium selenite was very individual and quite unpredictable.  It was recommended to measure blood selenium in each animal before deciding on the appropriate dietary amount of selenium to feed.  When the herd was placed on organic forms of selenium instead, the absorption and use was much more uniform across all individuals in the population.  I haven’t found a link to this study to post, but Alltech, a supplier of vitamin and mineral supplements, used this study in their promotional info in Canada probably 20 years ago, so you might have a look at their website for more details about selenium yeasts.  Dr Pagan from KER did a study that demonstrated much higher bioavailability of yeast-based selenium compared to inorganic forms, (Link to study) and many other researchers have demonstrated similar results with all the organic forms.

The other thing that is worthwhile noting is that inorganic selenium is not excreted very easily.  If you end up with a low grade toxicity, it can take months for the levels to drop back down to normal.  If you feed a feed that has selenium in one of those forms, it’s fine, but make sure you have your veterinarian check blood selenium levels from time to time and follow their recommendations for supplementation.  Please don’t sprinkle inorganic selenium on your feeds willy-nilly!  More is NOT better in this case!

The moral of that story is… when you are comparing different feeds, try to choose one that includes selenium in an organic form.  The chances of having normal blood selenium levels will be improved.

Finally, the end is near!

To summarize, evaluate your forage and determine how much additional protein and energy will be required from the concentrate portion of the ration.  Then, you can probably just pick a company that you like to deal with, as most have similar ranges.   Pick a feed from their range that has nutrients in a high enough concentration that your horses in intense work can meet their protein and energy requirements by eating no more than 5kg of hard feed so they can eat 5 kg of hay (or other forage) to meet fibre requirements and to maintain healthy gut motility etc.  Try to pick a feed that has a good quality protein, so pick one with a bit more soy, peas, lupins, or alfalfa, rather than just oats and barley.  If you want to avoid problems related to high carbohydrate diets, then look for higher fat diets with little or no oats and barley.   Finally, have a look at the trace minerals provided in the daily ration.  Pick a feed that has bioavailable forms of trace minerals in proper balance with each other.

Once you have selected a good quality, safe, and healthy feed, then you can probably feed it to most of the horses at your stable.  Spelling horses and smaller horses will need to eat less of it with more hay or grass.  Racehorses or broodmares etc will need to eat more of it.

Best of luck with choosing feeds.  Remember, we are happy to help you read feed and supplement labels, and we are happy to do feed comparisons for you contact us now.

If you haven’t read the proceeding articles on Reading Feed Labels follow the link to start at the beginning Reading Labels Part 1 – Equine Supplements Composition

30 Apr

Pro-Dosa BOOST is formulated to replace essential nutrients lost in training, competition, transport or stress, so many people use it to ensure their horses have the energy needed for competition, but did you know that Pro-Dosa BOOST contains nutrients that help manage your horse’s nervousness or excitability too?

There are several nutrients recognised to be important in the maintenance of normal nerve and muscle function when horses are under stress.  Magnesium, Tryptophan, Tyrosine, and Thiamine (Vitamin B1) have all been used for nervous horses, and these nutrients can have a greater impact when used in optimal balance together than when fed separately.

Magnesium is the most commonly known nutrient for calming. It is an essential mineral involved in nerve transmission, cardiac rhythm, muscle function, and relaxation. Low magnesium can lead to nervousness, loss of appetite, and poor body condition in horses.  This can be a vicious circle as nervous horses tend to use extra energy and sweat profusely, further depleting their magnesium stores.

Tryptophan is an essential amino acid required for the production of serotonin in the brain, and as serotonin functions to maintain mood balance, tryptophan has been associated with reducing distress and aggression. Essential amino acids are not produced in the body, so they must be provided in adequate quantities in the feed.  Some standard hay and grain diets are deficient in tryptophan.

Tyrosine is another amino acid that is an essential component to produce several brain chemicals called neurotransmitters; these help nerve cells communicate and influence mood.

Thiamine has a direct role in nerve impulse transmission and scientific research has shown it to relax horses. It is also important in energy metabolism and helps to control hyperactivity. Thiamine works cooperatively with magnesium and other B vitamins and should be given with calcium, which potentiates effect.   Thiamine is produced in the hindgut by microbes, providing the horse with sufficient amounts on a daily basis. Horses that are under stress or have impaired digestive functions, however, may not produce enough to meet requirements and benefit from supplementation.

Pro-Dosa BOOST contains all four of these vital nutrients in optimal balance with each other and with all of the other nutrients required for their absorption and function. It is important to remember that the body needs a full complement of nutrients in careful balance to achieve optimum health, performance and recovery.  Administration of individual nutrients may result in imbalances that actually impair availability and usefulness.  By providing all of the nutrients required in greater doses when horses are under stress, energy levels and attitude can both be supported, while normal appetite, thirst, and metabolism are also maintained.

For the past decade, Pro-Dosa BOOST has been used in 35 countries, in endurance, show jumping, eventing, hunt, and dressage horses, whether travelling and competing at a novice or international level, for performance, recovery and health.

30 Apr

There is a seemingly endless selection of “Horse Supplements” – powders, pastes, and liquids… But how do we know which one to choose?

There are so many supplements available for your horse on the market, figuring out which one to use can be an overwhelming task. Each product claims to be the best at aiding the horse, but is that really correct? How do we determine which is best for our horse and how do we know if it will meet its requirements?

When choosing a suitable supplement, there are several things to consider, but most importantly, we want to provide our horse with a safe and beneficial supplement that is easily administered.  Supplementation can be expensive, ineffective, and even detrimental if it isn’t carefully balanced.

We often get asked, why is Pro-Dosa BOOST provided only by syringe and not available in a bulk form?

Pro-Dosa BOOST is provided in an 80 ml syringe for…….

 Ease of administration with no wastage

  • Precise quantity of recommended daily nutrients in every dose…bulk formats may settle providing more at the bottom and less at the top
  • Security … a capped syringe prevents contamination
  • Stability… a syringe allows no ‘free air-space’, limiting oxidation (degradation) of nutrients
  • Compact and convenient, can be easily stored (especially when travelling)

Supplements are available in other various forms like liquids in bottles, powders in buckets or bags, and pastes in bulk to be administered via a drench gun. When using supplements like these, you must be careful that you don’t deliver less or more than your horse may require.

  • Nutrients (minerals, vitamins and amino acids) provided in powder, liquid and paste form will generally start to settle in layers, with heavier nutrients slowly moving to the bottom.  This process is known as sedimentation.    It is caused or facilitated by movement and occurs over time.  When product sedimentation occurs, it is nearly impossible to know how much of each nutrient is actually contained in a scoop or dose. You can’t guarantee that each of the nutrients are administered in the correct quantity and even if they are provided in the bucket in correct ratios, imbalances may result.
  • Powders placed in feed often create palatability issues and can cause feed refusal. Horses may try to eat around the powder, if not fully mixed, or refuse to eat any of the feed provided. The result is wasted feed, supplement, and cost.
  • When product is used from a bucket or bottle, more ‘free space’ is left and filled with air. Where air contacts the surface of product, oxidation can occur.  This is a form of degradation which can affect the quality of the nutrients.  Powders can absorb moisture from the air, which causing molding, clumping, and hardening, making them more difficult to use or entirely unusable.
  • Contamination can occur when a lid is left off a bucket or bottle. A manner of contaminants could fall in, quite unnoticed. Bacteria, molds, and even other products or pharmaceuticals, accidentally introduced, when fed to your horse could potentially lead to illness, product viability issues, or positive drug tests.
  • Using a syringe or drench gun from a bulk container can facilitate the spread of illnesses and viruses throughout a stable. ‘Double dipping’ the syringe from horse to horse or back to the container of liquid or paste is it not the most hygienic practice. While most manufacturers would recommended the thorough cleaning/disinfection of drench guns between horses, in a stable setting, this is rarely done.

It is important to remember that the body needs a full complement of nutrients in careful balance to achieve optimum health, performance and recovery.  We feel that providing Pro-Dosa BOOST via a syringe is the easiest, most reliable, safest, most hygienic and most cost-effective way to provide your horse with complete and correctly balanced nutritional support. You can be assured that Pro-Dosa International Ltd have and always will continue to produce a secure product with unsurpassed quality.

If you would like more information on what to look for when reading a supplement label make sure you read our blog article Reading Labels Blog …

Any further questions you can contact us by Ph: +64 9 238 8482, send us an email or visit our website