fbpx

Tag Archive for: supplements

Image of a set of scales with yes on one side and no on the other

Magnesium for Horses: Which Form is Best?

/in /by

With so much focus on magnesium in equine diets, you may be wondering what’s the best form of magnesium for horses.

There are many ‘forms’ of magnesium available and suitable to be fed as magnesium supplements. Unfortunately, at the moment there aren’t any extensive studies that look at the comparative bioavailability of these various forms of magnesium in horses.

To help us understand which forms of magnesium are best for horses, let’s first look at where and how magnesium is absorbed.

How is magnesium absorbed?

In the horse, magnesium is absorbed from the small intestine (Hintz et al 1972), with the second half of the small intestine being slightly more effective at absorbing magnesium than the first half. It is thought that very little magnesium is absorbed from the hindgut in the horse. Small intestinal absorption of magnesium is similar to that seen in humans, rats and rabbits.

Magnesium can be absorbed a few different ways. It is thought the major process via which magnesium is absorbed is simply via passive diffusion. This is a process where magnesium simply moves from an area of high concentration to an area of lower concentration, so in the case of intestinal absorption, when the concentration of magnesium in the gut is higher than in the intestinal cells the magnesium will move across membranes to enter the body. The concentration of magnesium drives absorption in this situation so the more magnesium present in the gut, the higher the concentration and therefore the more that will be absorbed.

Solvent drag, where magnesium dissolved in water in the gut is transported into the body as water is absorbed is a second route of magnesium absorption while active transport where magnesium is transported via some sort of magnesium pump that requires energy to operate and physically drag magnesium from the gut into the body is the third mechanism demonstrated in magnesium absorption. Which of these routes of absorption play the most important role in magnesium transport in horses is unknown.

What form of magnesium is easiest for horses to absorb?

It is difficult to compare the bioavailability of various forms of magnesium between studies because different experimental methods and forms or qualities of magnesium supplements are used. A relatively recent study (2005) published in the journal ‘Magnesium Research’ reported the magnesium bioavailability from 4 inorganic and 6 organic mineral salts of magnesium in rats. This was the most comprehensive study I was able to find that studied bioavailability across a broad number of forms of magnesium in a monogastric animal (albeit, a rat).

What did they find?

The results are interesting with 2 very clear points made by the authors (Coudray et al) being:

  • There were no ‘major differences’ in the intestinal magnesium absorption between the 10 forms of magnesium studied.
  • All ten salts, whether they were organic or inorganic were equally efficient in restoring blood magnesium levels in plasma and red blood cells in rats.

They did however report that magnesium gluconate had the highest magnesium absorption and retention rate of all the products studied. Magnesium sulphate (commonly known as Epsom salts) and magnesium carbonate had both the lowest absorption and retention rates and this was confirmed by the fact these two supplement forms also had the highest faecal magnesium excretions.

Their results are summarised in the table below (Coudray et al 2005).

% Mg Absorption* % Mg Retention*
Magnesium Gluconate 57 36
Magnesium Citrate 50 34
Magnesium Chloride 49 35
Magnesium Oxide 48 34
Magnesium Pidolate  48  32
Magnesium Lactate  48  27
Magnesium Acetate  47  30
 Magnesium Aspartate  47  26
Magnesium Carbonate  44  22
Magnesium Sulphate  35  19

What does this tell us?

While this is only one study, it does serve to demonstrate, as the authors have noted, that all of these forms of magnesium are suitable and capable of restoring magnesium levels in magnesium deficient animals. It also means that blanket statements like ‘organic magnesium is more bioavailable than inorganic magnesium’ are not supported by this research as while 2 forms of organic magnesium were the most bioavailable, magnesium chloride and magnesium oxide were the 3rd and 4th most bioavailable according to this study.

Factors to consider before you choose a form of magnesium for your horse

Looking at these results only it would seem that magnesium gluconate or magnesium citrate would be the best forms of magnesium to use while magnesium chloride appears to be the most useful inorganic source of magnesium. However, there are the following factors you should consider:

  • How much magnesium is in the product – all of these various forms of magnesium contain different amounts of magnesium and therefore you would need to feed different amounts to achieve the required daily intake of magnesium. If for example you wanted to feed enough of one of these ingredients to add an additional 10 g/day of magnesium to a diet you would need to feed from as little as 17 grams of magnesium oxide to a huge 186 grams of magnesium gluconate (see the table below). Feeding the products like magnesium gluconate that contain only very small amounts of magnesium quickly becomes unpractical and will become expensive.
Form of magnesium % Magnesium Amount required to feed 10 g of Magnesium/day
Magnesium Gluconate 5.39 186
Magnesium Citrate 16.2 62
Magnesium Chloride 11.98 83
Magnesium Oxide 60.3 17
Magnesium Pidolate  8.6  116
Magnesium Lactate  10  100
Magnesium Acetate  11.3  88
 Magnesium Aspartate  7.49  134
Magnesium Carbonate  26.23  38
Magnesium Sulphate  9.9  101
  • Palatability – some sources of magnesium like magnesium chloride are notoriously unpalatable, so despite being a good source of magnesium from a bioavailability perspective, if you can’t get your horse to eat it, it isn’t going to help much. Magnesium sulphate is also well known as an unpalatable source of magnesium.
  • Cost – typically organic minerals are more expensive than inorganic minerals, so even though they might be slightly more bioavailable, they will be more expensive, even if their superior bioavailability is accounted for. For example, magnesium citrate is approximately $40/kg. To feed 5 grams per day of magnesium that is absorbed you would need to feed 62 grams of this supplement per day (based on the 50% bioavailability observed in rats). This would cost $2.48/day. Compare this to magnesium oxide at $10/kg. To feed 5 g/day of magnesium that is absorbed you would need to feed 35 grams per day which would cost 35 cents per day. So even though magnesium oxide is less bioavailable on a percent of magnesium absorbed basis, it costs less to feed the same amount of theoretically bioavailable magnesium.
  • Physical availability – some of these more obscure forms of magnesium are difficult to source, so even if they appear to be a good option for supplementation if you can’t access and purchase it easily, practically it isn’t going to work for you.

It is easy to get caught up in the bioavailability of minerals and to lose sight of the bigger picture. Always remember when assessing a mineral source to look at bioavailability together with these factors discussed above.

Magnesium Oxide

In taking all of these factors into account, magnesium oxide, which has been used as a magnesium supplement for humans and animals for decades is showing itself as an attractive option. Magnesium oxide is easy to source, cheap to buy, contains a lot of magnesium per kilogram, so you don’t need to feed a lot to achieve the level of magnesium you want in the diet and it appears to be readily absorbed in the small intestine.

However, you do need to be careful with the type of magnesium oxide you buy and use. Magnesium oxide is made via a process of calcination where a source of magnesium like magnesite or magnesium carbonate is burned at very high temperatures to produce magnesium oxide. The way the magnesium is calcined and its final particle size affect bioavailability, with product calcined at less than 800C or with a large particle size being less bioavailable. While selecting fine particle size product is relatively simple because you can see particle size to a large degree (ie fine powders versus granular forms), it is going to be difficult to know in some cases how well the product was calcined. My best suggestion is to purchase magnesium oxide from known manufacturers that produce magnesium oxide specifically for use in animal rations. ‘Causmag’ is an example of a company that does this.

Take home message

There is actually very little known about the bioavailability of magnesium in horses. Data in rats shows us that both organic and inorganic minerals are bioavailable and that both forms are capable of restoring blood magnesium levels in magnesium-deficient animals.

However, when you take into account the amount of each supplement you would need to feed to achieve the required daily magnesium dose, the cost of the different forms of magnesium, palatability and availability factors, magnesium oxide appears to be the most practical and cost-effective magnesium supplement available for use in horse rations.

When selecting magnesium oxide for your horses, use products from reputable companies known for producing magnesium oxide for use in animal rations and select the finest particle size product you can get.

 

If you’re looking to help your horse be more calm and relaxed, check out our blog on Feeding for Calm Behaviour.

 

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

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

Click here to join the FeedXL Horse Nutrition Facebook Group

 

An image of many different green herbs together, which can potentially be included in a horse's diet

Herbs: Where Do They Fit in Your Horse’s Diet?

/in /by

The use of herbs as a source of compounds beneficial in promoting good health dates back many (many) thousands of years. In the age before ‘synthetic’ drugs, herbs were the only available source of potentially health-enhancing compounds and as such, they were used extensively. But where do herbs fit in a horse’s diet?

With modern day medicine now able to reliably reproduce the specific chemical components of plants that have the desired biological effect, herbs are not so prominent in the treatment or prevention of disease. Herbs are, however, still enormously popular both in human and equine diets. This newsletter is going to look, in a very broad sense, at how herbs are and perhaps should be used for equines.

‘Herbs are medicine’

The true and traditional role of herbs is to provide biologically active ‘medicines’ to treat or prevent disease states. I am the first to confess I know little about the use of herbs as medicine. A true understanding of how to use herbs effectively to treat or prevent certain diseases requires a full understanding of disease pathophysiology and the chemical actions of the herbs themselves. To understand all of this fully would take many years of committed study.

Herbs can certainly play a valuable role in the treatment or prevention of disease when used together with conventional or complementary medicine, but to use them effectively, they must be used correctly. Discuss the use of herbs or herbal preparations with your trained herbalist and ALWAYS include your veterinarian in these discussions. Quite a few herbs can have interactions with traditional medicines which if not fully explored can result in negative consequences. For example, ginger has been shown to increase bleeding time, so if it was used in conjunction with other anti-clotting drugs or if your vet was unaware your horse was being supplemented with ginger prior to undertaking surgery there may be complications with excessive bleeding.

Natural doesn’t necessarily mean safe

It is common for people to mistakenly believe that because herbs are natural, they are also completely safe. Because herbs contain drug-like components, many of them have the ability to become toxic if fed in too large an amount. Because a horse is such a large animal, the risk is, in reality, probably quite small, but you should always investigate potential toxicity for any herb you are considering to use. Garlic is a good example of an herb that, if fed in too large an amount, can have negative consequences, with severe anaemia possible in this case.

Some herbs also accumulate high concentrations of certain minerals, with many plants being selenium accumulators and seaweed or kelp a good example of a group of plants that accumulate potentially toxic levels of iodine.

Additionally, even though some herbs can have positive effects, like nearly every modern medicine available, many also have the potential to cause negative side effects. Ginger, for example, has been shown to reduce post-exercise recovery time, but it is known to cause gastric ulcers in humans (presumably if it is taken regularly or in large doses) and is theorised to do the same in horses.

Herbs as nutritional supplements

Many herbal preparations are sold today as ‘complete nutritional supplements’ and yet are sold without any form of typical analysis to support the claim that they are providing a complete range of nutrients that the horse needs in its diet. Herbs are also used singularly to provide vitamins and minerals to a horse’s diet, but in very few cases are herbs actually able to provide enough of any nutrient to have an impact on your horse’s overall nutrient intake.

Herbs are just plants, and with the exception of selenium accumulating plants, seaweed which accumulates iodine, and perhaps rosehips as a source of vitamin C, herbs really aren’t capable of providing significant amounts of vitamins or minerals in a diet.

For example, garlic is commonly fed as a source of copper and selenium. While garlic does contain copper and selenium, horses are so large and the typical dose of garlic so small that adding garlic to a diet has no real impact on the diet. The table below shows the daily contribution of 250 grams of garlic (a massive dose and one that researchers at the University of Guelph, Canada observed to cause anaemia) to the diet of a 500 kg horse in moderate work (shown as percent of Recommended Daily Intake or RDI):

Nutrient % RDI supplied by 250 g/day dried garlic
Calcium 2.8
Phosphorous 3.25
Copper 1
Zinc 1.5
Selenium 2.75
Manganese 2
Iodine 0.0
Iron 1.5

Enter any herb we have in the FeedXL database to your diet and you will see that even in large doses they have little to no useful impact on the nutrient content of a diet.

That is not to say all herbal preparations are not worthwhile. Some well-trained herbalists with a good understanding of nutrition have nutritional supplements that contain herbs together with more conventional sources of nutrients to give you supplements that do contain useful levels of vitamins and minerals together with complementary support from the herbs.

If you are buying herbal supplements that are being sold as nutritional supplements ALWAYS request a typical analysis. If one is not available, you should question how the supplier knows it is a nutritional supplement if they can’t even tell you what nutrients it contains. Don’t spend your hard-earned money on supplements that promise a lot without any sort of evidence to back it up.

Balanced diets, best results

As always, a balanced diet should underpin your horse’s entire health regime. While the use of herbs can certainly help support and promote good health or assist in the treatment of disease, if you are feeding herbs on top of diets that contain deficiencies of critical vitamins or minerals their effectiveness will be severely limited. Using FeedXL to first balance your horse’s diet, then working with your trained herbalist to devise a herbal strategy specifically for your horse will give you the best results.

Spice it up!

Herbs can certainly play a valuable role in maintaining or promoting the health of your horse. If you wish to use herbs as part of your horse’s routine health plan, you should keep the following in mind:

  • Use herbs only from trusted suppliers that can guarantee the consistent quality of the herbs.
  • Always discuss the use of herbs with your vet, particularly if your vet is also prescribing modern medicines for the treatment of a particular condition.
  • Understand the herbs you are using, particularly their potential toxicities so that you can use them to good effect without having them cause their own problems.
  • Don’t forget that very few herbs contain nutrients in high enough concentration to contribute substantially to any horse’s diet. If you are buying herbs as nutritional supplements always request a typical analysis for the product.
  • If you are using herbs like seaweed to provide a particular nutrient, always use FeedXL to calculate accurate dose rates to avoid overfeeding and creation of nutrient toxicity.
For more information on seaweed as a horse supplement, read our blog: Seaweed: Miracle Supplement or Massive Con?

 

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

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

Click here to join the FeedXL Horse Nutrition Facebook Group

 

Seeds in a glass bowl and oil in another container, both sources of omega 3 fatty acids for horses

Omega 3 for Horses: What, Why, How?

/in /by

What is Omega 3?

‘Omega 3’ is a term used to describe a group of fatty acids that cannot be made by an animal. They are therefore classified as essential fatty acids because they must be consumed in the diet. There are three ‘Omega 3’ fatty acids; the ‘short chain’ alpha-linolenic acid (derived from plants) and the ‘long chain’ eicosapentaenoic acid (EPA) and docohexaenoic acid (DHA) (available almost exclusively from oily fish). Alpha-linolenic acid is the only form of Omega 3 present in a horse’s natural diet. This form of Omega 3 can be transformed (elongated) into EPA and DHA via a metabolic pathway in the horse’s body. EPA and DHA are the two biologically active forms of Omega 3.

What does Omega 3 do?

Omega 3 fatty acids are important constituents of all cell membranes. They are primarily needed for the production of eicosanoids, including leukotrienes (involved in inflammatory responses), prostaglandins (involved in smooth muscle contraction and inflammation), and thromboxanes (involved in blood clot formation). All cells in a horse’s body except the blood cells produce eicosanoids and the eicosanoids have their effect directly on the cell that produced them. They are highly potent chemicals and absolutely essential for the normal functioning of a cell.

Omega 3 fatty acids are also important in maintaining cell membrane structure and function as well as central nervous system development and immune function, plus they have a role in male fertility, affecting the shape, motility and concentration of sperm in seminal fluid.

Why is the Omega 6 to Omega 3 ratio important?

Omega 6 is another essential fatty acid. Omega 6 is present in equine diets as the ‘short chain’ linoleic acid (the plant form of Omega 6) which is then transformed (elongated) to the biologically active ‘long chain’ forms of Omega 6 known as dihomo-gamma-linolenic acid (DGLA) and arachidonic acid (AA). Both Omega 3 and Omega 6 are required in the equine diet. Omega 6, like Omega 3 is an important constituent of cell membranes and plays a critical role as a precursor for the eicosanoids (leukotrenes, prostaglandins and thromboxanes) that control swelling, inflammation, clotting and dilation.

The reason the Omega 6 to Omega 3 ratio is important is the plant derived Omega 3 fatty acids and Omega 6 fatty acids share a common enzyme in the first step of the metabolic pathway they need to travel to be ‘elongated’ into the long chain forms of Omega 3 and 6 fatty acids (which are then used to produce physiologically active prostaglandins).

Omega 3 fatty acids are first elongated to EPA and then EPA is turned into what are termed ‘series 3 prostaglandins’. Omega 6 fatty acids are elongated to DGLA which is then turned into ‘series 1 prostaglandins’ or AA which leads to the production of ‘series 2 prostaglandins’.

The first step in the elongation of Omega 3 and 6 fatty acids requires an enzyme called Delta-6 Desaturase (D6D). If there is too much Omega 6 present in the cells where prostaglandin production is occurring, the Omega 6 will ‘outcompete’ the Omega 3 fatty acids for this enzyme. The result being overproduction of the Omega 6 derived prostaglandins and not enough of the Omega 3 derived prostaglandins. The Omega 3 prostaglandins tend to have an opposing or modulating effect on the Omega 6 derived prostaglandins (Omega 3 derived prostaglandins aren’t necessarily anti-inflammatory, but they are less inflammatory than their Omega 6 relatives). The ultimate effect of too much Omega 6 in a diet is increased inflammation, increased risk of blood clotting and constriction of blood vessels.

Interestingly, phenylbutazone’s (Bute) mode of action is to block these same pathways, preventing Omega 6 fatty acids from being transformed into pro-inflammatory prostaglandins.

With the competitive nature between Omega 3 and Omega 6 and the consequences of a diet too high in Omega 6, the ratio of Omega 3 to Omega 6 in any animal’s diet (including our own) is extremely important.

Other nutrients including biotin, vitamin E, zinc, vitamin B12 and vitamin B6 are also reportedly required to allow the efficient transformation of alpha-linolenic acid to EPA and DHA.

What is the recommended Omega 6: 3 ratio in a horse’s diet?

To date there is no established ratio of Omega 6: Omega 3 in a horse’s diet. However, if we look at the diet horses evolved to eat, being primarily grasses and herbs, we can start to hypothesise that horses should have a diet that contains more Omega 3 than Omega 6. We suggest at the very most a horse’s diet should contain 1 part Omega 6 to 1 part Omega 3.

How much Omega 3 and Omega 6 are in common horse feeds?

Forages contain more Omega 3 than Omega 6 while grains contain more Omega 6 than Omega 3. Some oilseeds like sunflowers contain more than 200 times as much Omega 6 as Omega 3 while other oilseeds like linseed (flax) contain close to 3.5 times more Omega 3 than 6. A detailed breakdown of the amount of Omega 3 and 6 in common horse feeds is shown in the table below (data from Premier Nutrition).

Ingredient Name Omega 3 (%) Omega 6 (%) O6: O3 Ratio
Pasture (3.5% Crude Fat)* 1.8 0.6 0.3: 1
Grass Hay 1.0 0.3 0.3: 1
Alfalfa/Lucerne Hay 0.5 0.4 0.7: 1
Oats 0.1 2.4 19.5: 1
 Corn/Maize  0.03  1.9  55: 1
 Barley  0.1  1.1  9.1: 1
 Rice Bran  0.2  6.6  37: 1
 Wheat Bran  0.2  2.1  11.6: 1
 Sunflower Seeds  0.13  27.1  206: 1
 Full Fat Soybean  1.4  9.8  7.2: 1
 Soybean Meal  0.1  1.0  7.2: 1
 Lupins  0.7  1.5  2: 1
 Faba Beans  0.1  0.9  12.8: 1
 Copra Meal  0  0.2  N/A
 Canola Meal  1.1  2.2  2.0: 1
 Sugarbeet Pulp  0.04  0.2  5.8: 1
 Soybean Hulls  0.2  1.1  7.2: 1
 Brewers Grains  0.2  2.2  9.3: 1
 Dried Distillers Grains (maize)  0.1  3.8  55.4: 1
 Linseed (Flax) Whole  19.1  5.6  0.3: 1
 Linseed Meal  4.5  1.3  0.3: 1
 Coconut Oil  0.1  2.0  20: 1
 Cod Liver Oil  24.5  2.0  0.1: 1
 Canola Oil  9.8  19.5  2: 1
 Soybean Oil  7.2  51.7  7.2: 1
 Sunflower Oil  0.3  60.5  206: 1
 Corn Oil  0.9  55  55: 1
 Olive Oil  0.7  10.8  15.7: 1
 Linseed (Flax) Oil  57.4  13.9  0.24: 1

* Data from Mel’uchova et al (2008)

Diets primarily based on forages that don’t use large amounts of oils like corn or sunflower oil should contain more Omega 3 than Omega 6. Diets that contain a moderate to large amount of grain and small amounts of forage (like the typical racehorse diet) will almost certainly contain far more Omega 6 than Omega 3.

Is there research to support the use of Omega 3 fatty acids in horses?

Most of what we know about omega fatty acids is derived from research in other animal species including humans. There is however some equine research that does lend support to supplementing diets with Omega 3 fatty acids. In a study that used 16 horses with arthritis, Manhart et al (2009) reported that horses supplemented with DHA and EPA experienced a greater decrease in joint fluid white blood cell counts and lower plasma prostaglandin E2 levels (an Omega 6 derived prostaglandin which is a pro-inflammatory pain producer and plays a major role in osteo-arthritis. It is this prostaglandin that many non-steroidal anti-inflammatory drugs block the production of to reduce pain and inflammation).

A study published in the Canadian Journal of Veterinary Research in 2002 (O’Neill et al) looked at the ability of flaxseed to reduce the inflammation associated with culicoides (midge) hypersensitivity (sweet itch or Queensland itch). These researchers reported that feeding 1 lb of flaxseed per 1000 lb of bodyweight to horses (or 0.5 kg per 500 kg bodyweight, equivalent to 3.5 oz or 100 ml of flaxseed oil) over a period of 42 days reduced inflammation and the size of the area that reacted to culicoides extract which was injected into the skin. In contrast to this study however, Friberg et al (2002) reported that horses supplemented with either 200 ml/day of flaxseed oil or 200 ml/day of corn oil showed no difference in the lesional surface area associated with culicoides allergy or the number of times horses itched. O’Neill et al believe the difference between the results reported by these two studies may lie somewhere in the fact they used whole flaxseed and not just the extracted oil. Unfortunately, the omega 6 to omega 3 ratio was not reported in these studies. Horses in the Friberg et al study were maintained on ‘pellets’ so it is possible that their dietary Omega 6 ratio was too high for 200 ml of flax oil to have a noticeable benefit. It was noted in this study that a miniature horse receiving the full 200 ml dose responded particularly well to the supplement which may indicate that the dose for the larger horses needed to be much higher to have a significant benefit.

Brinsko et al (2009) studied the sperm quality in 8 stallions when they were fed their normal diets with or without a DHA-enriched supplement. This study found no difference in fresh sperm quality, however, as the semen was cooled and stored, sperm quality tended to be better when the stallions were supplemented with DHA. Most of the improvements observed however were not statistically significant (which means they may have just happened by chance and may not actually be due to the supplement).

Pagan et al (2010) reported that supplementation with 60 ml of fish oil significantly increased serum and red blood cell EPA and DHA while supplementation with 60 ml of corn oil significantly reduced red blood cell EPA levels. Pagan et al (2012) have also reported improved insulin sensitivity in horses supplemented with omega 3 fatty acids from fish oil.

When should you supplement?

If your horse’s diet contains a moderate to large amount of grain or high Omega 6 oils like corn or sunflower oil you may need to consider adding additional Omega 3 to the diet to keep the ratio of Omega 6 to Omega 3 at or preferably below 1: 1. Take the following diets as examples:

Diet 1 – High in Omega 3

10 kg/day (22 lb) Pasture
2 kg/day (4.4 lb) Alfalfa/Lucerne Hay
0.5 kg/day (1.1 lb) Oats
200 g/day (7 oz) Sunflowers
100 g/day (3.5 oz) Vitamin and Mineral Supplement

This diet will contain an Omega 6 to Omega 3 ratio of 0.4: 1 and does not need additional Omega 3 supplementation. The diet is however still higher in Omega 6 than a 100% forage based diet so some Omega 3 supplementation may be warranted in certain situations, for example if the horse is arthritic.

Diet 2 – High in Omega 6

2 kg/day (4.4 lb) Pasture
4 kg/day (8.8 lb) Alfalfa/Lucerne Hay
3 kg/day (6.6 lb) Oats
2.5 kg/day (5.5 lb) Corn/Maize
250 g/day (9 oz) (5.5 lb) Sunflowers
250 ml/day (9 floz) Corn Oil
100 g/day (3.5 oz) Vitamin and Mineral Supplement

This diet will contain an Omega 6 to Omega 3 ratio of 3.5: 1 and would benefit from additional Omega 3 supplementation. Adding 400 ml of linseed oil to this diet will lower the Omega 6 to Omega 3 ratio to 1: 1 and also allow for some of the high Omega 6 grain to be removed from the diet. You can monitor your Omega 3 and 6 levels and the ratio in FeedXL Premium and Advisor plans. Note however that most manufacturers do not yet include this information when reporting the nutrients in their products!

How should you supplement?

There are various ways to add additional Omega 3 to diets. The best-known Omega 3 supplement for horses is linseed (flax) oil. Linseed oil is 57% Omega 3, making it a useful Omega 3 supplement. Freshly ground linseed can also be used (read FeedXL Newsletter # 22 Feeding Flaxseed). Linseed meal will have very little effect on a diet’s overall Omega 6 to 3 ratio as even though linseed meal does contain more Omega 3 than 6, the amount of Omega 3 in linseed meal is so small it really won’t influence the overall diet’s Omega fatty acid ratio. Commercial Omega fatty acid supplements are also available and these now often contain fish oil to provide a direct source of DHA and EPA in the diet.

Of course, the best way to maintain a balanced Omega 6 to 3 ratio in your horse’s diet is to maintain them on a largely forage based diet and only use grains and oilseeds like sunflower seeds in moderate to large amounts where absolutely necessary.

Take home messages

  • Diets that contain a lot of grain or high Omega 6 oils like corn or sunflower oil may cause your horse’s diet to contain more Omega 6 than Omega 3 fatty acids.
  • Too much Omega 6 in a horse’s diet interferes with the body’s use of Omega 3 fatty acids. This imbalance could lead to excess inflammation and problems like arthritis.
  • To help modify the inflammatory reaction of a horse’s body to stimuli like exercise, the Omega 3 to 6 ratio needs to be kept in balance.
  • Omega 6 is just as important in the diet as Omega 3, they just need to be kept in balance with one another.
  • There is no established ratio of Omega 6 to Omega 3 for horses, however a horse’s natural diet contains more Omega 3 than Omega 6, so keeping your horse’s diet ratio at 1: 1 or less is logically what will be best.

 

 

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

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

Click here to join the FeedXL Horse Nutrition Facebook Group

 

Many garlic cloves, which are sometimes fed to horses

Garlic for Horses: Should You Feed It?

/in /by

Herbs have been used in some cultures as remedies for disease and illness for more than 5000 years and their effectiveness as part of an ‘integrated system of primary health care’ is well recognised. Given the benefits we see in humans, it is becoming more and more commonplace to use herbs like garlic for horses. However, in many cases for horses, herbs are used not as part of a holistic approach to health care, but rather as a nutritional supplement.

Herbs are commonly added to diets as sources of copper, sulphur, zinc, selenium and iodine. The problem is that most herbs actually contain very little of these nutrients (with the exception of iodine in seaweed). So, to supply any real amounts of nutrients, these ingredients need to be fed at high levels … The problem is, some herbal products like garlic can be toxic for horses, especially if you feed them at high rates. So, if you are considering feeding garlic to your horse, you first need to consider the potential benefit to be gained versus the risks involved.

Why is garlic even considered as a feed ingredient?

The answer to this question is likely because we as humans have used it with good effect in our own diets for thousands of years. Traditionally in human medicine, garlic is used as an anti-microbial agent. A compound called allicin, present in garlic, is known to have an anti-microbial effect which (along with some other compounds) is thought to give garlic this property. Garlic also has a well-liked taste and smell and is used to give food flavour.

As humans, we all too often fall into the trap of thinking what is good for us must be good for our animals. But take chocolate, macadamia nuts, garlic and onions as an example. All of these foods are eaten extensively by humans and all (yes, even chocolate) have health benefits when eaten in moderation – yet every one of these foods is poisonous to dogs, highlighting that just because we can eat it and receive health benefits, it doesn’t mean that our companions, including our horses can.

We really don’t know the answer to this question. There is also a question over whether it kills off beneficial bacteria in the horse’s gut, which the horse relies on to digest fibre. I guess the real question is WHY do we want to feed a horse an anti-microbial agent all the time? It would make more sense to only feed one when the horse is at risk of microbial infection. We would never consider giving antibiotics all the time, so why is garlic any different. Perhaps the perception that it is ‘natural’ makes us feel more inclined to use it all the time rather than just when it may be needed. Sometimes it is fed all the time in a horse’s diet not as an anti-microbial, but as a nutrition supplement, raising the question of whether it is useful for this purpose.

Does garlic provide a horse with beneficial nutrients?

As a nutritional supplement to supply vitamins and minerals, garlic rates poorly. Feeding 100 grams of dried garlic per day (which is far more than I suspect any of you would be feeding) provides the following nutrients for a 500 kg horse in moderate work (shown as percent of Recommended Daily Intake or RDI):

Nutrient % RDI supplied by 100 g/day dried garlic
Calcium 1.1
Phosphorous 1.3
Copper 0.4
Zinc 0.6
Selenium 1.1
Manganese 0.8
Iodine 0.0
Iron 0.6

As you can see from the table above, garlic provides less than 2% of a horse’s daily requirement for these minerals and as such is virtually useless as a ‘mineral supplement’.Try this in your own horse’s diet in FeedXL, enter 100 grams of garlic in the diet and look at the graph to see what it contributes to the diet; its nutritional effect is virtually nil.

Is garlic safe for horses?

There is much debate over whether or not garlic is safe to feed horses. A study conducted by Wendy Pearson at the University of Guelph, Canada in 2005 found that when fed at high levels (250 g/day for a 500 kg horse) garlic caused an array of changes in the horse’s blood including an increase in mean corpuscular volume (MCV), decreases in red blood cell count and blood haemoglobin concentration. These changes eventually led to a condition known as Heinz Body Anaemia. While the dose rate they used was high, the researchers note that currently a safe dose rate for horses is unknown. Because research has not been carried out looking at feeding lower doses of garlic over a long period of time we don’t know ‘scientifically’ if it is safe or not.

Onion, a close relative of garlic and containing the same toxic component (n-propyl disulfide) is also known to be toxic to horses, with research conducted in 1972 showing that consumption of onion tops caused severe anaemia. Again, this study used large amounts of onion tops to produce life threatening anaemia within 11 days, meaning the question of whether onions and garlic would be safer at lower levels still remains. However, US veterinarian Dr Karen Hayes notes in her article “Feeding Garlic – The great garlic debate” that she sees a handful of cases of Heinz Bodied Anaemia every year resulting from horses consuming wild onions in amongst their pasture or in horses who have raided a compost or garden and eaten garlic or onions, suggesting perhaps that the dose doesn’t need to be high for effects to occur. In any case, the effects the researchers have observed when feeding garlic or onions at high levels have been severe. While feeding garlic at lower levels over long periods of time may not cause a life-threatening anaemia, it may be causing anaemia that is mild enough not to be overtly noticed, but prevalent enough to reduce your horse’s stamina and performance and Dr Hayes suggests it may even affect a horse’s ability to resist disease.

If you do feed garlic and wish to continue feeding it, it would be a good idea to run a blood analysis on your horse to make sure their mean corpuscular volume, haemoglobin and packed cell volume levels are in the normal range and that no Heinz Bodies are present.

So, should you feed it or not?

Our stand on feeding garlic to horses is unless there are DEFINITE and DEMONSTRABLE benefits associated with feeding garlic to your specific horse, don’t feed it. While it is true that it hasn’t been proven that lower dose rates of garlic will harm your horse, it also hasn’t been proven that feeding garlic to your horse provides any specific benefits. We also don’t know what garlic does to horses when fed consistently at low feeding rates.

Next time you go to tip garlic into your horses feed just take a moment to consider why you are feeding it, what benefit the horse is getting and whether it is worth taking the potential risk, even if it is only a small one. There is no doubt herbs can make valuable nutraceutical additions to diets but if you are considering using them as nutritional supplements, use FeedXL to see what it is they are actually adding to the diet.

 

 

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

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

Click here to join the FeedXL Horse Nutrition Facebook Group

 

Three spoons full of flaxseed, an ingredient often included in horse diets

Feeding Flaxseed

/in /by

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

What does flax add to a diet?

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

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

When can flaxseed be used?

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

How should flaxseed be prepared for feeding?

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

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

Does flaxseed have to be boiled before feeding?

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

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

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

What about soaking it?

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

Can flaxseed meal be fed?

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

Other possible side effects

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

Summary

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

 

 

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

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

Click here to join the FeedXL Horse Nutrition Facebook Group

 

Seaweed for Horses: Miracle Supplement or Massive Con?

/in /by

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

What is seaweed?

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

Why seaweed for horses?

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

Is seaweed a good trace mineral supplement?

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

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

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

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

How much iodine does seaweed contain?

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

How much iodine do horses need?

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

Can seaweed cause iodine toxicity?

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

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

Is there any time that seaweed is useful in a horse’s diet?

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

4 things you must do before you feed seaweed to your horse

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

A special note about seaweed for mares and foals

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

The final slime…

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

 

 

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

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

Click here to join the FeedXL Horse Nutrition Facebook Group

 

Many horses grazing on grass and eating out of buckets on the ground

Grains for Horses: Cooked or Uncooked?

/in /by

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

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

Why we cook grains

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

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

How starch is “packaged”

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

 

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

 

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

 

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

 

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

How does this packaging stop starch digestion?

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

 

Enter cooked grains…

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

How cooking helps

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

What about cracked grains?

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

Does soaking grains help?

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

What happens if cereal grains are fed without being cooked?

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

What about oats?

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

And the moral of the story…

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

 

 

 

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

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

Click here to join the FeedXL Horse Nutrition Facebook Group

 

A close up photo of a horse eating hay

Biotin: Should You Supplement?

/in /by

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

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

Biotin is naturally available to your horse

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

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

An unbalanced diet causes poor quality hooves

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

The best way to achieve good quality hooves

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

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

When should you use biotin?

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

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

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

 

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

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

Click here to join the FeedXL Horse Nutrition Facebook Group

 

© FeedXL