Below are some of the more common questions we get asked. If you can't find an answer to what you're looking for here, get in touch with us and we'll do our best to answer your questions as quickly as possible. We'll be updating this section regularly.


FREQUENTLY ASKED QUESTIONS
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1.    Why use chelated calcium?
2.    Why not just feed more ordinary calcium (DCP, Lime etc)?
3.    Why has the formula changed for Bone Formula?
4.    How is Bone Formula Forte double strength when the grams per kilo are not double?
5.    Why can’t the entire calcium content of a supplement be chelated?
6.    Why no phosphorus or magnesium in Bone Formula Forte?
7.    Why so much more copper than zinc in Bone Formula Forte?
8.    Chelated is lower in elemental value, so how can we feed less than we did before?
9.    If Bone Formula Forte is fed with another vitamin & mineral supplement, could it throw out the mineral ratios?
10.    The new formula has a strong smell and one of my horses refused it? ***Updated Feb 2018***
11.    How much bone formula forte is chelated?
12.    I’m using Calsorb Forte, do I need to feed a salt block too?
13.    If you feel magnesium is important enough to bring out a product, why didn’t you add it to Bone Formula Forte?
14.    If magnesium is covered by the roughage and other feed stuffs, why have you brought out a product?
15.    Can a horse have too much magnesium?
16.    Why shouldn’t I just get mag oxide from the produce store?
17.    Some people say magnesium can sedate a horse, is this true?
18.    How does magnesium effect muscles? How does it help nervousness and excitability?
19.    The more sugar and starch in the diet the more magnesium is required….is this true?
20.    The recommended daily intake of vitamin E is 1000iu? Where else do horses get vitamin E?
21.    Vitamin E is required in higher doses for horses on oil supplements, why?
22.    Synthetic vs natural vitamin E – the consensus is if it is synthetic, you need to feed more, and natural forms are absorbed and utilised better.
23.    Why are B vitamins important for horses?
24.    What are the benefits of vitamin B?
25.    Can I just feed brewer’s yeast?
26.    What kind of situation / individual would EzyMAG+ supplement suit?
27.    Can I feed EzyMAG+ with Bone Formula Forte? And if so, would I then be covering the majority or all vitamin and mineral requirements?
 

WHY USE CHELATED CALCIUM?

To address the problems of calcium-deficient feeds and diets, Dr Jennifer Stewart's Bone Formula® Forte and Calsorb® Forte are formulated with organic chelated calcium which is protected from phytate and oxalate binding.

The benefits include:

  • chelation protects calcium from interactions with other minerals, phytates and oxalates
  • chelation presents calcium to the absorption sites in the intestine
  • chelated calcium is embedded and protected in a ring-like structure
  • in the presence of oxalates and phytates, organic chelated calcium is more bioavailable than inorganic forms

The chelated calcium in Dr Jennifer Stewart's Bone Formula® Forte and Calsorb® Forte is manufactured under the pharmaceutical industry's most stringent quality controls so you can be sure they're free of contaminants or impurities that impede accurate prediction of bioavailability.
 

WHY NOT JUST FEED MORE ORDINARY CALCIUM (DCP, LIME etc)?

Depending on oxalate and phytate levels in pasture and feeds and the extent of osteoporosis in each horse, you may have to feed up to 1/2kg of lime a day to meet the calcium requirements - and there is a limit to how much calcium the body can absorb.

Plus, this amount of lime will reduce absorption of other minerals. Considering the dangers of osteoporosis, the use of scientifically sound formulations that are bioavailable, is essential. Horses with correct calcium and phosphorus intakes exhibit better growth, joint cartilage health, bone mineral density, tendon strength and soundness.

This principle holds true for adult horses and is essential for young horses, brood mares and working horses - who need a steady, reliable source of minerals for tissue maintenance and resilient immunity.
 

WHY HAS THE FORMULA CHANGED FOR BONE FORMULA?

We researched and formulated Bone Formula over 10 years ago and in the subsequent decade we have gathered a vast amount of information on different horses, pastures and clinical cases. This information guided the new formula. By increasing the amount of chelated calcium, we can provide for a wider range of horses in different grazing and feeding situations. It also allows a lower feeding rate for horses not in the highest risk category.

We increased the selenium and iodine because the most recent NRC (Nutrient Requirements of Horses) and other ongoing research into minerals and horses, have shown that the previously recommended levels were too low.

As most people are aware, mineral ratios are also important. The calcium to phosphorus ratio is critical for bones, and the calcium to magnesium ratio is critical for muscles and nerves. Horses need between 10 and 30 grams of these major minerals every day. The majority of these macro-minerals are provided by the roughage. For example mixed pasture provides around 7 grams of phosphorus and 7 grams of potassium per kg of grass – a 400kg horse would be eating around 15kg a day – so that’s a lot of minerals and it shows that the forage, hay and chaff are the major source of these minerals.

Horses eat up to 2kg of soil a day and this is also a major source of minerals.

Trace elements are often deficient in soil/pasture/hays/chaff and hard feeds - including grains and pollard etc. and the ratios are important. The recommended ratio for iron:copper:zinc:manganese is 4:1:3:3.

We have been collating actual pasture and soil analyses collected over the last 10 years and combining them with published figures on mineral availability and absorption for different soils and grasses. What we found was that pasture zinc levels are often high and copper levels low. Iron intake from soils and pasture is also high. Based on this field and clinical research, we reformulated the levels of copper, zinc and manganese in Bone Formula Forte. The increased copper and manganese work well with the majority of pastures, hard-feed diets and feedstuffs commonly used by owners.
 

HOW IS BONE FORMULA FORTE DOUBLE STRENGTH WHEN THE GRAMS PER KILO ARE NOT DOUBLE?

The double strength refers to the chelated calcium which is 2-3 times stronger in the new BONE FORMULA FORTE. The reason for doubling the strength is that case studies and clinical trials (including x-rays and blood tests) showed that the degree of osteoporosis in horses on oxalate pastures can range from mild to severe.

Bone biopsy is the only way to find out how demineralised the skeleton is, and to measure remineralisation. However, our x-ray studies and research by other scientists and vets have shown that remineralisation can take up to 12 months. We can’t do these studies on every horse but based on the history, length of time on oxalate pastures and clinical signs, we know that some horses need extra help to shorten the time taken to restore bone calcium levels. With the new double-strength formula, these horses can easily get the extra calcium without having to be fed huge amounts (300g a day). The double strength also means that other horses get the same calcium but in smaller dose.

When we did our research on parathyroid hormone (PTH) in horses on setaria and kikuyu, we found that PTH levels dropped back to normal within a couple of weeks of being on Bone Formula. This showed us that:

1.  the horses were absorbing the BONE FORMULA calcium into the blood
2.  the horses were no longer moving calcium out of their skeleton to replenish blood levels

That’s great news! But it takes a lot longer than a couple of weeks to replace all the calcium that was already taken out of the bones when the horse couldn’t get enough calcium from the grass. So although PTH levels tell us the horse is no longer taking calcium OUT of the skeleton, they can't tell us whether they are moving calcium back INTO the skeleton.

The double-strength formulation assists horses reverse the osteoporosis faster.

We have also provided a range of feeding rates. This is to enable owners to feed according to their horse’s individual situation. For example, some ponies weigh 150kg and some 400kg. The smaller ponies would be fed the lower amount. Young horses and ponies and pregnant mares need more calcium than other horses – so they should be fed the higher end of the range.   There are also differences in the types and amounts of oxalate pastures that horses graze – and some are hand-fed and others are not. And there are differences in how long horses have been on oxalate-pastures and how much oxalate is in the grass (this varies with season, rainfall, fertiliser etc. and even between paddocks). Again, by providing a range of dose rates, you can adjust the amount fed according to your situation. If you have been using the original Bone Formula with success, for example feeding 50g per day, you should have the same effect feeding 25g of the new Bone Formula Forte.
 

WHY CAN’T THE ENTIRE CALCIUM CONTENT OF A SUPPLEMENT BE CHELATED?

Horses don’t need that much chelated calcium and it would be wasteful and expensive. And we wouldn’t be able to include the trace elements if we just provided calcium. Also horses need some inorganic calcium to bind to the oxalates in the gut. This stops the oxalates from being absorbed into the blood and damaging the kidneys. 

The really important thing to keep in mind is that we are not endeavouring to perfectly balance the mineral content of the entire diet – we are just attending to the oxalate problem and supplying trace elements.

The major minerals like phosphorus, potassium and magnesium are provided by the hay, pasture, chaff and hard feed. Because every horse has a different diet, it would be impossible to make one mineral supplement that would balance and match every diet! Generally we can use published values for the mineral levels in different feeds – but if you want to be very precise you need to analyse your particular hay and/or pasture. Also bear in mind that mineral levels in hay and pasture change with the stage of growth, time of year and soil type. Your state department of agriculture or local agronomists can assist with these analyses.
 

WHY NO PHOSPHORUS OR MAGNESIUM IN BONE FORMULA FORTE?

Phosphorus and magnesium are MACRO minerals ie horses need large amounts (between 10 and 30 grams per day). We are not attempting to provide these in Bone Formula Forte. Bone Formula Forte provides trace elements (in milligrams) and addresses oxalate concerns in pasture and phytates in hard feeds.

The majority of the major minerals are provided by the roughage and hard feeds. To balance the major minerals requires an analysis of the pasture and hard feed as these are the main source of phosphorus, magnesium and potassium. Because the total daily intake of phosphorus from the roughage and concentrate determines the amount of calcium the horse needs (Ca:P > 1.2) and the amount of magnesium required depends on the calcium level of the roughage and concentrate (Ca:Mg < 2:1), the requirements depend on the type of pasture/hay/roughage. Published figures can be used for these major minerals and extra magnesium added if required.

Remember too that it is the total daily intake of minerals that is important and that no single supplement can address all the different mineral and trace element requirements because the total daily intake varies with the diet.

Finally, the equine kidney is extremely sophisticated and has a major role in excreting excess minerals.

Also see our news page for the article 'Phosphorus, the other side of calcium.'
 

WHY SO MUCH MORE COPPER THAN ZINC IN BONE FORMULA FORTE?

Because most pastures/hays and chaff are high in zinc and lower in copper, so we took that into consideration when reformulating. As horses usually get enough zinc from roughage and soil each day, they usually don’t meet their copper requirements.

In absolute terms ie the total daily intake in milligrams, as well as the ratios of copper to zinc, the new formula more closely matched requirements under Australian conditions.
 

CHELATED IS LOWER IN ELEMENTAL VALUE, SO HOW CAN WE FEED LESS THAN WE DID BEFORE?

Because there is more chelated calcium in the new formula. With 3x the amount a lower feeding rate is fine.
 

IF BONE FORMULA FORTE IS FED WITH ANOTHER VITAMIN & MINERAL SUPPLEMENT, COULD IT THROW OUT THE MINERAL RATIOS?

The major source of the macro-minerals like phosphorus, potassium, sodium, chloride and magnesium is the pasture/hay/hard feed. Most vitamins are covered by pasture – if only on hay, they will likely need extra vitamin A, C, E and K – however this is mostly for performance/hard working horses.

It is the trace elements that are usually deficient.  No other trace element supplement should be needed for horses on Bone Formula Forte except on veterinary advice.
 

THE NEW FORMULA HAS A STRONG SMELL AND ONE OF MY HORSES REFUSED IT? ***UPDATE FEB 2018***

The strong smell to our new formula was due to the higher concentration of minerals. Like any new supplement, we recommended feeding smaller amounts at first and increasing to the required amount over a couple of weeks. This helps the horses get used to the taste and they are less likely to refuse it. 

UPDATE FEB 2018 - Your feedback and stories are important. Over the course of the year we were made aware, that for some horses, Bone Formula Forte was being refused at the feed bin. The thought of these horses not receiving this sometimes life-saving supplement meant that finding a solution to the palatability problem for those horses went straight to the top of our list of priorities.

The reality is that minerals don’t taste or smell great, especially for those horses that have a predisposition to pickiness with their food. We did some research and put several flavours to trial. We ensured that we used a wide variety of horses in the trial including some that had flat-out refused the current formula. We even used a rescue brumby that wouldn’t even go near the feed bin even if the formula was hidden in the feed. We and the owners of the horses in the trial were thrilled when we achieve a 100% success rate with the new flavour and the other good news is that we were able to make this change without affecting the price tag. Thanks to all the owners and horses who took part in our trial. We really do appreciate your help! 

The new flavour goes into production February 2018.
 

HOW MUCH BONE FORMULA FORTE IS CHELATED?

Commercial in-confidence proprietary information.
 

I'M USING CALSORB FORTE, DO I NEED TO FEED A SALT BLOCK TOO?

No, Calsorb Forte provides salt.

Also, because Calsorb Forte contains amino acids and a range of minerals, it has a distinctive taste. Salt blocks are usually just salt + molasses and (like us) horses have a preference for salt and sugar – and will select them over something more nutritious. When using Calsorb Forte no other salt licks or blocks should be provided, except on veterinary advice.
 

IF YOU FEEL MAGNESIUM IS IMPORTANT ENOUGH TO BRING OUT A PRODUCT, WHY DIDN’T YOU ADD IT TO BONE FORMULA FORTE?

The amount of magnesium required depends on the other minerals in the diet. Most of the minerals are in the roughage. 

The magnesium was removed from Bone Formula Forte because the amount a horse requires depends upon the mineral intakes from roughage and any concentrates/commercial feeds (which varies from 1 to 10g/kg!). The amount of magnesium required depends on the amounts of other minerals in the total daily diet - this affects mineral ratios which are important as well.

For example:
Fresh Lucerne/clover/legume pasture has, 2-4g magnesium/kg
Fresh grass pasture has 1.4-3.5g magnesium/kg
Grass/meadow/oaten hay chaff has 1.3-3g magnesium/kg
Bran has 3-5.4g magnesium/kg
Oats have 1-2g magnesium/kg
Commercial feeds (Mitavite, Hygain, Prydes etc) have 2.5-10g magnesium/kg 

Hay is the horse's major source of minerals and it's the hay you need to balance. And even the hay will vary with stage of cutting and season, and soaking hay for 10-30 minutes significantly reduces magnesium content.

Some horses and diets actually need extra calcium, some extra magnesium – and some neither! Therefore, because requirements vary between horses and because it’s the total daily intake that is important, it is not possible to make a standard amount appropriate for all horses.

The best way to determine what levels of magnesium you should be using to balance the diet is by a diet analysis. We have formulated EzyMAG+ on the basis over 5000 diet analyses. 


IF MAGNESIUM IS COVERED BY THE ROUGHAGE AND OTHER FEED STUFFS, WHY HAVE YOU BROUGHT OUT A PRODUCT?

Roughage is not balanced for every mineral and remember, it’s the TOTAL DAILY INTAKE that’s important, not the amount in one feed.

The amount of magnesium required depends on the amounts of other minerals in the total daily diet and varies from horse to horse. For example, magnesium requirements are increased in cycling mares and fillies, transport, insulin resistance (and laminitis/founder), Cushing’s disease (PPID), equine metabolic syndrome, muscle problems (including twitching and tying-up), nervousness and excitability.

Blood magnesium levels change with hormonal changes. For example, when oestrogen increases (i.e. when fillies and mares come into season), magnesium levels drop.  Some mares and fillies are more prone to twitchiness, flighty behaviour, muscle pain and tying up at this time, and many benefit from extra magnesium. Muscle pain, nervousness and tying-up are all found in horses with a subclinical magnesium deficiency, and any horse that ties-up can benefit from extra magnesium in their diet.  

The two most common manifestations of increased magnesium requirements are muscle problems and "jumpiness".  As with any nutritional deficiency though, there are vast individual variations in how sensitive the animal will be. 


CAN A HORSE HAVE TOO MUCH MAGNESIUM?

Feeding more than the needed amount is never better, although with magnesium the deficiencies are often so sizeable it's difficult to overdo it. 

Magnesium absorption from feeds varies from 40-60%. Magnesium in EzyMAG+ is 70% absorbed. Studies in magnesium toxicity have not been done but the upper limit of intake is thought to be 8g/kg of feed – so a 400kg horse eating 10kg of feed per day, the upper limit would be 80g per day. 


WHY SHOULDN’T I JUST GET MAG OXIDE FROM THE PRODUCE STORE?

There can be contaminants and impurities in bulk products – depending on the source, supplier, quality control, whether other products are produced in the same factory and means of production. 

The magnesium in EzyMAG+ has one of the finest particle sizes and is of the highest quality.
 

SOME PEOPLE SAY MAGNESIUM CAN SEDATE A HORSE, IS THIS TRUE?

MgSO4 is used intravenously as a sedative and muscle relaxant during anaesthesia. There is no evidence that dietary magnesium has these effects. 
 

HOW DOES MAGNESIUM EFFECT MUSCLES? HOW DOES IT HELP NERVOUSNESS AND EXCITABILITY?

Signs of a magnesium deficiency or an increased requirement for magnesium, include nervousness and behavioural issues, and muscle problems through to tying-up. 

Magnesium deficiency also causes mineralisation of the aorta with changes in the wall of the artery occurring within 30 days on a deficient diet. Muscle weakness and muscle tetany have also been reported in horses with magnesium deficiency. 


THE MORE SUGAR AND STARCH IN THE DIET THE MORE MAGNESIUM IS REQUIRED….IS THIS TRUE?

There is a very strong association between magnesium and the body's ability to use insulin properly. Magnesium-deficient diets can induce insulin-resistance (which prevents the muscles and liver from taking up sugars and they are diverted to fat for storage). Magnesium-rich diets have been found to be protective in many cases of insulin-resistance.

Magnesium is needed for optimal muscle contraction, the utilisation of glucose and to sustain the high oxygen consumption necessary for athletic performance. Research indicates that magnesium facilitates oxygen delivery to working muscle tissue – so there is an increased need for magnesium by horses in work that need high starch-sugar feeds. Magnesium levels can be depleted by antibiotics and other pharmaceuticals too. And because the amount of magnesium in the blood does not necessarily correlate with the amount stored in the body, a magnesium deficiency can be difficult to pinpoint. 
 

THE RECOMMENDED DAILY INTAKE OF VITAMIN E IS 1000IU? WHERE ELSE DO HORSES GET VITAMIN E?

There are 8 different naturally-occurring vitamin E compounds and fresh pasture has the highest levels, followed by hays made from immature grasses 30-100iu/kg; grains have less than 20-30iu/kg and levels decline by up to 73% during 12 weeks storage. So, the intake varies considerably with dietary source.
 

VITAMIN E IS REQUIRED IN HIGHER DOSES FOR HORSES ON OIL SUPPLEMENTS, WHY?

Oils = fatty acids. Fatty acids interact with oxygen when exposed to air, or used in the body. This process, called peroxidation, results in the production of ‘oxidants’ as the fatty acids become ‘oxidised’, so it is often recommended that additional antioxidants be added to the diet, to mop-up the extra oxidants. (When fats and oils smell rancid it is a sign that they have been exposed to air and the oil has become oxidised by oxygen). 

Oxidants are the by-product of reactions in the body that use oxygen – similar to the toxic waste products produced by energy generation in power stations.
The body has an oxidant defence system to protect its cells from oxidant damage – oxidants are also known as reactive oxygen species (ROS). The system includes vitamin C which is a water-soluble anti-oxidant (bit like the navy!) and vitamin E, which works in fatty tissues in the body. 

We can measure the amount of oxidative stress in the body by measuring markers in the blood. These markers are elevated after exercise (which causes increased oxygen usage and therefore more ROS produced) and in horses with low vitamin E levels and high oil intakes – indicating that horses with increased oxidant loads need more vitamin E, even when only moderate levels of oils are fed.

The general rule-of-thumb for the prevention of peroxidative damage is to provide a minimum of 100 IU of vitamin E per 100 ml of vegetable oil.


SYNTHETIC VS NATURAL VITAMIN E – THE CONSENSUS IS IF IT IS SYNTHETIC, YOU NEED TO FEED MORE, AND NATURAL FORMS ARE ABSORBED AND UTILISED BETTER.

Supplements and feeds with added vitamin E use α-tocopherol.
Naturally-occurring vitamin E (the form of 2R4R8R or triple-R) has an activity of 1.36iu/mg whereas the synthetic form has 1iu/mg. This means that more α-tocopherol (synthetic) needs to be fed to get the same level of activity.


WHY ARE B VITAMINS IMPORTANT FOR HORSES?

It has recently been recognised that although production of B-vitamins in the gut is enough to meet the needs of ruminants, this is not so in the horse. Gut bacteria in horses do produce B-vitamins, but the production and absorption or both may be insufficient under some circumstances. Published figures (NRC) has been found to be inadequate and a doubling of intake is recommended for exercising horses.

Dietary levels of thiamine (vitamin B1) are good in fresh hay and grains, but fall to 50% after 6 months in storage, almost zero after 2 years. In hot, humid weather, levels fall even faster.

Providing extra thiamine has been shown to improve appetite and energy metabolism and decrease nervousness. The trouble with thiamine deficiency is that the effects are reduced growth rate and performance ability – both of which are subclinical and difficult to identify – but certainly a 10% in either means growth or performance will not be optimal or ideal.

Pyridoxine (vitamin B6) is needed by horses for muscle strength, protein synthesis (i.e. new cell and tissue building), energy and red blood cell production. Requirements are increased in young, growing pregnant and exercising horses. It is produced in the gut – but not well-absorbed. Levels in feeds reduce with feed storage. Current recommendations for B6 are 5 times higher than levels published 10 years ago (NRC). 
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WHAT ARE THE BENEFITS OF VITAMIN B? 

Most B-vitamins are involved in the production of energy to maintain life processes – i.e. ATP, DNA processing, amino acid processing, and protein building – all absolutely necessary for life. The effects on growth and performance of subclinical deficiency are difficult to detect or diagnose, so provision of correct intake is important. 


CAN I JUST FEED BREWER’S YEAST? 

You would need to feed 1 ½ kg of brewer’s yeast each day to meet thiamine (B1) requirements and 2kg per day to meet pyridoxine (B6) requirements.


WHAT KIND OF SITUATION/INDIVIDUAL WOULD EZYMAG+ SUPPLEMENT SUIT? 

All horses need correct intakes – but especially young, growing, pregnant, exercising horses and those that have had surgery or been sick or injured as well as horses suffering from veterinary conditions such as tying-up, laminitis, Cushing’s or metabolic syndrome.


CAN I FEED EZYMAG+ WITH BONE FORMULA FORTE? AND IF SO, WOULD I THEN BE COVERING THE MAJORITY OR ALL VITAMIN AND MINERAL REQUIREMENTS? 

EzyMAG+ can be fed with Bone Formula Forte. Additional supplementation should only be necessary on veterinary or nutritionist advice.  Its total daily intake that counts – so diet analysis is the best way to determine if all requirements are met. 
 

NEED MORE INFORMATION?

If you have further questions please contact us by email or call us on 02 4365 0806.

If you would like to purchase our products please contact AIRR or Cenvet to find your closest store - details are on the contacts page.