Bran benefits

Bran, often in the form of bran mash, has long been fed to horses as a source of fibre or laxative to help prevent colic, as a warm and palatable feed for sick horses or those with poor teeth and after a hard days hunting. However, should these feeding practices be considered as words from the wise or an outdated tradition?

One of the biggest problems associated with feeding bran is its very high phosphorus content. The ratio of calcium to phosphorus in the horse’s diet should be ideally maintained at 1.5-2:1 (1.5-2 times more calcium than phosphorus) but in comparison, bran contains 10-12 times more phosphorous than calcium. High levels of phosphorus decrease calcium absorption, resulting in deficiency. Consequently, calcium is drawn from bones (where 99% of calcium is stored) which in serious cases, causes them to weaken. Although far less common now, feeding large amounts of bran and consequently high levels of phosphorus, can result in ‘Millers Disease’ (Nutritional Secondary Hyperparathyroidism); a condition which eventually results thickening and distortion of bones caused  by lost minerals being replaced with fibrous tissue.

Feeding small amounts of bran on an infrequent basis will not cause major mineral imbalances, but as we all seem to appreciate that new feeds should be introduced gradually, why make an exception for bran? In fact, some researchers believe that this could have a negative effect on the hindgut microbes responsible for fibre digestion. Research has also shown than bran does not act as laxative, regardless of whether it is fed wet or dry. Instead, any ‘laxative effect’ is likely to be the caused by the mild disturbance or irritation resulting from the sudden introduction of a new feed.

For people, fibre (including bran) can increase the bulk of stools by helping them to retain more water and consequently make them easier to pass. However, fibre requirements in horses are much higher and whilst bran does contain fibre, the content is much lower (10-12%) than in sugar beet (20% - unmolassed) and hay.  In fact even as a source of water, the benefits of a bran mash may be questionable when you consider the small amount of water actually consumed in comparison to the horse’s daily requirements.

Many of us reach for a mug of hot chocolate or soup in colder weather and whilst a feeding a warm bran mash may be a comforting thought, it will not continue to keep your horse warm after he has eaten it.  As a result of fermentation in the large intestine, the digestion of hay and other forages produces heat (regardless of the weather) and therefore nutritionally, feeding additional hay is more likely to help keep your horse warm.

Whilst feeding bran will not always result in serious harm, particularly if properly balanced and fed in small amounts to adult horses; reported benefits are based largely on tradition. Consider whether adding bran to your horse’s diet is really necessary as unfortunately, it is one feeding tradition that may potentially cause more harm than good.

Seaweed: A word of caution

Seaweed supplements have long been fed to horses and perhaps you feed or have fed a seaweed supplement to one of your own horses? Seaweed is often promoted as being an effective broad spectrum vitamin and mineral supplement, a good source of amino acids and a beneficial joint supplement. However, due to the potentially high iodine content, feeding seaweed could have harmful effects.

Iodine is one of 8 ‘micro minerals’ which by definition, means it is needed in very small amounts by the horse. Although only needed in small amounts, iodine is essential for the production of thyroxine and tri-iodothyronine (thyroid hormones), which influence numerous aspects of horse health including metabolism, heat regulation and bone development. However, iodine is one of the few minerals that can be harmful when oversupplied and for which intolerable levels can be reached relatively easily.

Iodine toxicity is more common than deficiency and in most cases, is the result of over feeding high iodine supplements such as seaweed. Even for horses without access to grazing, the recommend ration of compound feed, broad spectrum vitamin and mineral supplement or balancer should easily meet the horse’s iodine requirements without the need for additional supplementation. In fact, because all of the vitamins, minerals and amino acids are naturally occurring (and the levels at which some are provided), a seaweed supplement alone will not provide a balanced diet. In addition, there is no scientific evidence to suggest that seaweed is beneficial joint supplement.

It is estimated that a 500kg horse needs 1-2mg of iodine per day, with the National Research Council (NRC – the accepted institute for standardising animal diets) setting toxic levels at 50mg per day (or 62.5mg for very hard working horses). However, some nutritionists believe that ‘undesirable effects’ or even toxicity can be reached at much lower levels.

Seaweed supplements may typically contain around 835mg of iodine per kilogram and may be recommended at a rate of 50-150g per day for a 500kg horse (iodine levels and recommended rations of seaweed do vary between suppliers). Based on these figures, owners could be providing 42-125mg of iodine per day from seaweed alone. Whilst not all companies selling seaweed recommend rations containing toxic levels of iodine, some nutritionists question whether it is ‘good for horses’ to be oversupplied with a nutrient required in such small amounts.

Excess iodine poses greatest risk to pregnant mares, potentially causing infertility, abortion and due to the high concentration on iodine in the placenta and milk, weakness and goiter (swelling of the thyroid gland) in foals. In non-pregnant, adult horses, iodine toxicity can cause hypothyroidism; a condition which affects thyroid function/ hormone production and can result in  goiter, obesity, poor coat condition, lethargy and intolerance to cold.

Seaweed can be fed safely to horses and may have some benefits to offer. However, if you are using a seaweed supplement, first and foremost establish whether or not you reaching toxic levels of iodine (a nutritionist will be able to offer advice on this) and if the answer is yes; remove or reduce your supplement and never provide ‘free access’ or ‘ad-lib’ seaweed.. If not, it may still be worth asking yourself whether you are oversupplying iodine unnecessarily and if any benefits of feeding seaweed could be achieved more appropriately.

Protein: Is it the root of all evil?

In science lessons we are taught that proteins are ‘the building blocks of life’, essential for growth and repair. This is true for us and also true for our horses. Proteins consist of long chains of amino acids, 10 of which (there are 22 in total) cannot be synthesised by the horse and therefore must be provided by the diet. This considered, can protein really be responsible for as many problems as is often believed?

Too much protein is often thought to cause/ contribute to conditions such as laminitis, colic and tying up. However, years of research has shown that nutritionally, excess starch and sugar (including fructan in grass) is often responsible and not protein. If undigested in the small intestine, starch and sugar is rapidly fermented in the large intestine resulting in the production of lactic acid. This causes damage and death to gut bacteria which can consequently lead to conditions such as laminitis and colic. Whilst many factors can have an effect nutritionally, it is also high levels of starch and sugar that can cause/ exacerbate excitability. So if research tells us otherwise, why is protein often deemed the culprit?

One possible explanation could be the law surrounding feed labels. Protein content must be declared on feed labels but for many years, this was not the case for starch (must now be declared if making a claim i.e. ‘non-heating’). Consequently, if moving to a higher energy feed resulted in a change of behaviour or episode of laminitis, many owners may have thought the increase in protein (and not the hidden increase in starch) was responsible.

Aside from the conditions above, lumps and bumps on the skin and filled legs are the most common reasons owners ask me for advice on low protein diets. Although traditionally diagnosed as ‘protein bumps’, in many cases, lumps and bumps are not diet related. True feed allergies are very rare are the result of a specific type of protein and therefore reducing the amount fed would be unlikely to help (see previous blog on allergies).

When not accompanied by heat or lameness, being stabled for longer periods i.e. overnight is generally considered to be one of the most common causes of filled legs. In fact, there is no reason why excess protein should cause filled legs and therefore any accompanying feed changes are likely to be coincidental.

Although there are some clinical conditions which do demand a low protein diet (namely liver and kidney damage); protein is essential for growth, life and health and certainly does not deserve the bad press it often receives.