Bran mashes Useful tradition or nutritional pariah? | Trainer Magazine | European Trainer Article Index

Nov 30

Nov 30 Bran mashes Useful tradition or nutritional pariah?

IN ITS most common form a bran mash consists of a warm sloppy mixture of wheat bran, with other minor ingredients such as rolled barley, linseed, vegetable oil, honey, molasses or date syrup often being added. The exact recipe for a particular yard’s bran mash is often a closely guarded secret, being regarded as part of a winning formula, and it could have been handed down through the generations of trainers. Traditionally a warm ‘mash’ has been offered to horses following hard exercise, or sometimes just once a week on the day of no or limited exercise, which is commonly a Sunday. Some of the oldest horsemanship texts give us insight into the rationale for a bran mash as part of a racing diet. Bran mashes were seen as having a purgative or laxative effect and so were used in the belief that they would help to cleanse the digestive tract and maintain the normal movement of the gut, thus preventing impactions following hard exercise and during days of rest. Bran mashes have also been used to encourage normal eating and water intake during periods where appetite may be suppressed such as in sick horses, following surgery, or simply after racing or hard days of work. They have also been used as a method for introducing medications or other additives given on a periodic basis. In clinical settings, wheat bran is also combined with paraffin oil in an attempt to soften faeces and help resolve early stage impactions within the digestive tract, although in this application the wheat bran really only serves as the carrier for the paraffin oil, which can of course be introduced by the veterinarian via nasogastric tube. When evaluating the usefulness of wheat bran mashes, we need to consider the main nutritional characteristics of this ingredient and evaluate whether it’s suitable for the job. Wheat bran, as the name suggests, is a by-product of the production of flour from wheat, made from the high fibre outer layers of wheat, whereas wheat feed or wheat middlings, which are widely used in horse feed pellets, contain much more of the inner layers of wheat including some germ and endosperm. From a negative viewpoint the fibrous outer layer of cereals including wheat bran can harbour undesirable mycotoxins. Nutritionally wheat bran is high in fibre, which has a relatively low digestibility. It is also comparatively high in protein, but the starch content is relatively low, as most of the starch would be located in the grain portion of the wheat itself. Wheat bran provides a low level of digestible energy and also has a low bulk density, and so it is able to absorb large amounts of water or other liquid. As with most cereals and their by-products, wheat bran is very low in calcium and comparatively high in phosphorus giving a most unsuitable calcium-to-phosphorus ratio. The perceived laxative effect of wheat bran in horses probably reflects its use in human nutrition. Our digestive tract does not have the well-developed fibre fermenting capacity of a horse’s. In people, the insoluble fibre from wheat bran travels through our digestive tract largely unchanged and so adds bulk to the faeces giving rise to its reputation for ‘keeping you regular.’ Horses have a superior fibre fermenting capacity and studies to date have not confirmed a similar laxative effect. In fact some research at Cornell University in the US failed to show any change in faecal moisture when the concentrate feed was replaced by 50% wheat bran fed alongside hay. Additionally, in terms of fibre intake, wheat bran is not that spectacular and certainly many other ingredients – such as hay, alfalfa, and oats – would offer a higher fibre content. The strengths of the traditional bran mash probably lies in its palatability and therefore its use to encourage eating, where appetite is suppressed. Improvement of water intake, when voluntary drinking is reduced, is another potential benefit. However, there are two big negatives to bran mashes that have demonised their use with nutritionists worldwide, the first being the appalling calcium-to-phosphorus delivery. Being pragmatic, bran mashes are rarely given in isolation and are usually fed as part of a well-balanced ration. Equally, it is a relatively simple task to add a little limestone to the historical bran mash recipe in order to rectify this calcium-to-phosphorus situation, although the high level of phosphorus in the form of phytate may reduce the absorption of other minerals in the diet. Nutritionists also get very excited about the potential negative impact of the periodically fed bran mash on the microbial balance of the hindgut. A disruption to the normal balance of microflora in the hindgut is vey undesirable and may increase the risk of digestive disturbance. However, hindgut microbes generally respond badly to abrupt changes to what is being fed and so in some ways regular daily use of a bran mash may be more appropriate. It is possible to produce a bran mash recipe that has a balanced calcium-to-phosphorus ratio and which introduces other desirable ingredients such as Omega-3 rich full-fat linseed. When fed daily as part of the normal diet, a mash of this type is unlikely to upset the microbial balance and may offer some benefits in terms of feed and water intake in fussy feeders, although is unlikely to have any significant effect on faecal bulk or regularity.

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THIS ARTICLE FIRST APPEARED IN - EUROPEAN TRAINER - ISSUE 40

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