Feeding Salt to Horses

We normally think of salt more as a warm weather requirement.  Horses do require about 1-2 ounces of salt per day to provide help meet their requirement for sodium and chloride.  This requirement can increase to 4-6 ounces of salt per day in hot climates or under exercise where losses in sweat increase greatly.  Inadequate salt in the diet can result in abnormal eating behavior such as licking or chewing objects which have salt on them (fork handles etc.) or licking/eating dirt.  Water intake may also decrease, increasing the risk of impaction colic. In more extreme cases, horses will stop eating and may experience muscle incoordination.

Cold weather salt intake is sometimes overlooked.  Horses do not lick salt blocks as readily as some other specie even when the salt block is a comfortable temperature.  During cold weather, outdoor salt blocks become even less inviting!  Would you lick something that is freezing cold?

A good option to maintain year around salt intake is to offer loose salt available free choice, either in stalls or in a covered mineral feeder.  Salt intake from loose salt has been observed to be higher than from salt blocks due to the ease of consumption.  When purchasing loose salt, ensure that you are selecting salt that is intended for animal consumption (NaCl, iodized table salt, plain white salt), and not a mineral salt blend (red salt), or salt that is intended for de-icing. 

If horses are salt starved, it may be a good idea to limit the amount of salt put out for them until they have adjusted their intake.  It is essential that fresh clean water at an appropriate temperature be available at all times as well. 

Commercial feeds normally contain 0.5-1.0% salt, so horses on this type of feed will typically consume less free choice salt than horses not receiving salt in their feed.  They may still benefit from having loose salt available free choice.  A salt block is better than not having any salt available free choice, but may not be as effective in maintaining salt intake in cold weather or when high intakes are required in hot weather.

Providing salt free choice is a good management tool that can help your horse eat and drink well all year long!

Feeding Electrolytes to Horses

As a follow-up to our recent post on providing adequate water for horses, the following information should be helpful in understanding the use of supplemental electrolytes for horses.  There are a wide range of practices and opinions within this topic, so here are some basic guidelines to keep in mind:

  1. Provide loose salt free choice at all times to all horses.  If loose salt is provided, horses will usually consume the right amount to meet their electrolyte requirements without having to use an additional supplement. 
  2. Horses administered any form of electrolytes need to be consuming adequate water.
  3. Electrolytes should never be force fed to a dehydrated horse, and any horses supplemented with electrolytes should be monitored for dehydration (skin pinch test, mucous membrane color and hydration, capillary refill).
  4. Electrolytes can be used to encourage drinking (e.g. during transport or if horse doesn’t like to drink away from home).  Usually thirst/drinking is stimulated within 3-4 hours after dosing. 
  5. In cases where horses are working extremely hard and losing electrolytes through substantial sweating, a supplemental electrolyte in addition to the salt may be beneficial. 
    1. If heavy sweating due to competition is anticipated, administer electrolytes 1-2 days prior to competition, during the competition and 1-2 days after a competition. 
    2. Doses are usually within the 1 – 4 oz range, depending on sweat loss and the heat and humidity levels. 
    3. A general rule of thumb is usually 30 – 90 g per hour of strenuous work, or follow manufacturer’s instructions if using a commercial product. 
  6. An oral dose (paste/syringe) is recommended over top dress or adding to water, as these methods can create palatability issues and can result in feed/water refusal.
  7. Many commercial products have more sugar that electrolytes in them, so buying a commercial product where sugar is not listed as one of the main ingredients is very important.  Potassium, sodium, chloride, and calcium are the most important electrolytes.

Water-The Most Important Nutrient for Horses

Water is the most important nutrient that we provide for horses on a year around basis. Horses need 2 to 3 times more water than other feedstuffs. An 1100 lb horse on a dry forage diet at an average temperature of 68 degrees Fahrenheit will need a minimum of 6-7 gallons of water per day or 48-56 lbs of water, and many horses will drink more water than the minimum. We all appreciate that the water requirement may double at high temperatures, but may not realize that at -4 degrees Fahrenheit; the quantity required is about 10-12 gallons per day, or actually higher than at moderate temperature. The onset of cold weather can actually increase the requirement for water because there is no fresh grass and the air is very dry.

There is a misconception that domestic horses can easily eat enough snow to survive. While horses in the wild do adapt to lower water intakes, partially because food intake is also frequently reduced, horses can survive longer without food than they can without water. Reduced water intake can also impair digestion and potentially contribute to the incidence of impaction colic.

It also requires a great deal of energy to eat snow, melt the snow in the body and raise the fluid temperature to normal body temperature of 99.5- 100.5. Increasing the temperature of 10 gallons of water from 32 degrees to 100 degrees takes about 1372 Calories or about the amount of digestible energy in a pound of feed. Melting the snow to get to water will take a great deal more energy and the horses will not readily eat a pile of snow the size of 20 five gallon buckets. It takes about 10 inches of snow to have one inch of water.

Providing horses with fresh clean water at an appropriate temperature all year around is a great management tool to reduce the risk of colic, maintain healthy digestion, maintain body condition and even save a bit of money on feed cost!

Feeding Horses in the Winter

Horse in pasture during snow fall

As I was reviewing the feed program for one of my client’s lesson horses, she mentioned ordering corn to add to the feed for the winter. She felt this would provide the horses extra warmth in the cold weather. This is a common winter practice with many farms, and I explained to my client that she was correct to increase the horse’s caloric intake with falling temperatures. There is a much better alternative to corn, though – it is much more efficient and effective to increase the forage portion of the diet to help create internal heat in the winter. This is due to the fermentation process the forage goes through in the hindgut, and the heat that process gives off.

The term “critical temperature” is used determine at what temperature a horses nutritional requirements change to maintain normal body temperature. I use the temperature of 40 F as a benchmark for calculating winter diets. In essence for every 1 degree below critical temperature, I increase the horse’s caloric intake by 1%. So, if my 1000 pound horse were receiving 18.6 Mcal (18,600 calories per day), I would increase his diet by 1860 calories when the temperature goes to 30 degrees (10 X 186). If my hay has tested at 1 Mcal (1000 calories) per pound, an additional 2 pounds of hay will help my horse maintain his body condition at that temperature.

I also encourage my clients to feed a well fortified concentrate during the winter months. The lack of fresh pasture, limited sunlight hours, and often diminished hay quality require better fortification. Make sure your horse feed provides adequate levels of vitamin A, D and E.  Feeds offering probiotics and prebiotics, as well as biotin are also encouraged. If you are feed a grass hay or alfalfa hay, make sure your calcium and phosphorus levels are also balanced accordingly in your feed.

Water consumption is imperative during winter months. Make sure that the buckets are free from ice and frozen debris. In the winter horses will consume 10 to 12 gallons of water per day. Ideally the water temperature should be at 50-65 F to encourage drinking.

Examine your horses body condition score monthly during the winter to maintain a healthy horse!