The problem with bran mashes
Bran and bran mashes are a traditional horse feed addition. A warm bran mash makes a nice snack on a cold day, especially after being worked, so where could the harm be?
The Good About Bran
Bran has been used as a horse feed addition for many years. It is generally well-liked by most horses and even picky eaters. Bran made into mashes is easy to eat and digest for old and sick horses or those who have gone off their feed. You can also add salts, medication and other supplements into it to disguise it for your horses.
Bran has Nutritional Imbalances
Your horse needs a specific calcium to phosphorus ratio of 2 to 1, or twice the amount of calcium in the diet than phosphorus (read more about calcium phosphorus ratio). Grains and grain by-products are actually deficient in calcium and have an excess amount of phosphorous (1). Depending on the grain, you can have anywhere from 6 to 12 times the amount of phosphorus than calcium. Wheat bran contains 0.07-0.2% calcium and 0.9-1.3% phosphorus (2).
Nutritional Secondary Hyperparathyroidism
Feeding a diet or feed option that is high in phosphorus and lacking calcium on a regular basis can increase the risk of your horse developing a calcium deficiency condition called Nutritional Secondary Hyperparathyroidism (NSH), commonly called “big head” or “bran disease” (1). While it is highly unlikely that this disease will result from only feeding a warm bran mash a few times over the winter, it has a higher risk of developing in horses that are fed diets high in cereal grains and grain by-products.
Rapid Changes in Diet
Changes to a horse’s diet should be made gradually over several days. It takes time for the digestive enzymes and healthy bacteria in your horse’s gut to adapt to new feeds. Rapid changes in feed, such as an occasional bran mash, can disrupt the normal enzyme and bacterial balance and cause digestive issues such as diarrhea, gas, and even potentially colic. Adding in a large feeding of bran mash will do just this.
Alternatives to Bran Mashes
There are many great alternatives to give your horse a nice warm feed on a cold winter day. If your horse is already on a supplemental feed, either in pellet or textured feed form, you can add hot water and prepare it as you would a traditional bran mash. If your horse is only on forage (whether hay or pasture), you can use hay pellets or cubes in the same manner adding hot water to make a forage mash. Your horse’s gut enzymes and bacteria are already adapted to these feeds so you are unlikely to cause digestive upset. Many of these supplemental complete feeds are also already balanced for calcium and phosphorus so there is no need to worry about NSH.
Additions such as salt or an electrolyte can then be added to this new warm feed mash. If you have a picky eater or a horse off their feed then a small amount of sliced apple or carrot can be added to help encourage their appetite.
If you still would like to use bran as a feed for your horse’s diet then the best thing to do is to work with an equine nutritionist to help ensure your horse’s diet is balanced for a proper calcium and phosphorus ratio and make sure his nutritional needs are being met.
References:
1 National Research Council. (2009). Nutrient Requirements of Horses. Sixth revised ed. pp. 250-251.
2 Heuzé V., Tran G., Baumont R., Noblet J., Renaudeau D., Lessire M., Lebas F., (2015). Wheat bran. Feedipedia, a programme by INRA, CIRAD, AFZ and FAO. https://www.feedipedia.org/node/726 Last updated on October 14, 2015. Accessed 14 January 2020.
Image: Kay, G. (N.D.) Endocrine: hyperparathyroidism. Available at: https://www.vetstream.com/treat/equis/illustration/endocrine-hyperparathyroidism-nutritional. Accessed 14 January 2020.
