Drought Feeding

By Dr Nerida Richards

This summer is going to present a huge challenge to horse owners all around Australia.  Australia is currently gripped by what some are describing as the worst drought they have ever seen.  While we have all seen droughts in our time, what makes this drought more difficult to deal with is that almost the entire country is affected.  So where in the past the north was able to support the south with hay and grain, or the west could support the east and vice versa, this year everyone is affected to some degree by drought meaning that hay and grain supplies are limited everywhere in Australia.

So what does this mean for you as a horse owner?  It means that you need to make some crucial decisions now and put a plan in place to ensure your horses come through the drought without experiencing undue hunger or stress.  The following article will take a practical look at what the horses most immediate nutritional needs are during a drought and ways you can satisfy these needs whilst avoiding problems such as colic.

What are horses' most immediate needs during a drought?


Water is always a horse's most immediate need, drought or no drought.  However, during this drought we are seeing water shortages all around the country.  You need to take a very close look at whether you have enough water on your property to provide your horses with drinking water over the coming summer months.  A mature 500 kg horse consuming dry pasture or hay will consume somewhere between 12 and 40 litres of water per day.  Lactating mares and horses that are working and sweating will have water requirements that are increased over and above these amounts.  In addition, hot weather will increase a horse's requirement for water.
Water quality also needs to be considered alongside the quantity of water available for your horses.  Water quality is affected by the amount of total dissolved solids in the water and may also be reduced by the presence of algae and bacterial contaminants.  If you are concerned about the quality of the water your horses have access to, you can have your water analysed by the Symbio Alliance Laboratories in Brisbane.  Symbio Alliance can conduct water quality analyses and will provide you with a report on the quality of your water based on the Australian stock water quality guidelines.  For more information on this service you can contact Elizabeth Owens at This email address is being protected from spambots. You need JavaScript enabled to view it. .  Water quality is particularly important for pregnant and lactating mares, young horses and horses that are working and sweating heavily.
If you don't have access to enough water for your horses or the water quality is not suitable for horses you may need to consider agisting your horses on a property where water availability and quality are not an issue.

Forage or high fibre feeds

Forage or high fibre feeds, which include feedstuffs like pasture (if you are fortunate to have any), hay and chaff is a horse's next most immediate need.  Feeding forages will keep your horse's gastrointestinal tract healthy and reduces the risk of diseases such as colic.  An absolute minimum of 1 kg per 100 kg bodyweight of forage must be fed per horse, per day to maintain normal gastrointestinal tract movement and function.

Suitable forages or high fibres feeds include:

  • Grass hay
  • Lucerne hay
  • Cereal hays (including wheaten, oaten, barley and triticale hay)
  • Lucerne chaff
  • Lucerne cubes
  • Clean, well cured silage
  • Oaten or wheaten chaff
  • Clean straw
  • Soybean hulls
  • Oat hulls
  • Peanut and almond hulls
  • Sunflower seed hulls
  • Lupin hulls
  • Copra meal
  • Sugarbeet pulp
  • Brewers grains

As a rule your horses forage/fibre requirement should supplied as a minimum 50% long hay or pasture.  The remaining 50 % can be supplied as any combination of hay or the shorter fibre length feed stuffs.  For example a 500 kg horse could have his minimum forage requirements supplied as:

5 kg/day of grass hay, cereal hay, lucerne hay or straw

Or as:

2.5 kg/day of grass hay, cereal hay, lucerne hay or straw
2.5 kg/day of chaff, hulls, copra or beet pulp

Forages that should be avoided include:

  • Sorghum hay and hay made from any of the sorghum grass family including Johnson grass and Sudan grass - these hays can cause cyanide poisoning in horses and should not be fed.
  • Red clover or alsike clover hay - these clovers have been known to cause photosensitisation and liver damage and should be avoided.
  • Vetch Hay - when fed in large quantities vetch hay may cause diarrhea.  If it is available to you, introduce it to your horse very slowly and cease feeding it immediately if any negative effects are observed

Uncommon forages

Given the severity of the current drought, common forages are difficult to source and already people are turning to sources of forages that are rarely if ever fed to horses.  These types of forages include:

  • Canola and other failed crop hays
  • Sugar cane hay or mulch
  • Large bale silage

Because there is very little, if anything known about the use of these forages in equine diets you must proceed with caution.  Speak with your nutritionist or veterinarian prior to introducing them to your horse's diet.  If they are happy for you to proceed, introduce them gradually into the diet over a period of 14 days.  Monitor your horse very closely during this time and cease feeding the forage immediately if you notice any negative effects.


After you have satisfied your horses forage requirements to maintain gut fill and gut health, your horse's next most immediate need will be energy.  Depending on its quality, the forage you are feeding will supply your horse with some of its energy requirement.  However, 1% bodyweight of forage won't be capable of satisfying your horses entire energy requirement.
Your horse's energy requirement will be dependent on its current activity. Lactating mares, working horses and growing horses have the highest energy requirements whilst spelling horses have the lowest energy requirement. To ensure you meet each horses energy requirement without wasting feed, divide your horses into groups that reflect their energy requirement status separating working horses from spelling horses and dry mares from lactating mares. You may also like to divide them into easy keeper and hard keeper groups. This will allow you to finely ration their feeds such that their energy requirements are met, but not exceeded, ensuring your feed supplies last as long as possible.  Once you have your horses separated you need to consider what and how much to feed them.

Suitable high energy feeds include:

  • Cereal grains
  • Legume grains (including faba beans, chickpeas, white lupins)
  • Sunflowers
  • Rice bran
  • Wheat bran and pollard
  •  Copra meal
  • Sugarbeet pulp
  • Peanut Meal
  • Brewers grains
  • Soybean hulls
  •   Oil

Because of the feed shortages we are facing, you may find that feeds you would not generally feed become your only option.  If you do find yourself in this situation, consult with your veterinarian or nutritionist prior to introducing the feedstuff into your horse's diet.  If they are happy for you to proceed, introduce the feed gradually over a period of 14 days and cease feeding immediately if you notice any negative effects.

A special note about cereal grains!

As a rule, cereal grains with the exception of oats should not be fed to horses whole or raw (please read the article 'Micronising - how it improves the value and safety of cereal grains' at All the facts on Micronising from Dr Nerida Richards (as above)).  Given that a drought sometimes forces us to feed outside of normal recommendations, some of you may find that your only option is to feed wheat, barley, triticale, sorghum or corn in an uncooked form.  If you are faced with this situation, you can avoid the very real risks of acidosis, colic and laminitis that are associated with feeding raw cereal grains by placing your horse on the recommended daily dose of FounderGuard®.  Please discuss the use of FounderGuard® with your veterinarian or nutritionist.

How much energy should you feed?

The amount of energy your horse needs will be reflected in their body condition score.  Body condition reflects the amount of fat a horse is carrying on its body.  Condition scoring your horse regularly during the drought will help you to assess if you need to feed more or less of the high energy feeds.  In a drought situation horses should not be allowed to fall below a body condition score of 4 (using the 1 to 9 scale of Henneke et al. 1983).  For more information on condition scoring please go to http://www.equilize.com.au/members-newsletter.php?newsletterid=9.  If your horse is losing body condition, you will need to increase the amount of high energy feeds you are feeding.  If your horse is gaining unescessary body condition, you can reduce the amount of high energy feeds you are feeding to ensure your feed supplies last as long as possible.


Protein is an essential nutrient for all horses.  Failure to provide enough protein in a horse's diet will contribute to muscle and organ degradation, reduced milk production in mares and slowed growth rates in young horses.  A protein deficient diet may also reduce the amount of energy the horse can extract from the fibrous portion of the diet as the bacteria in the hindgut need the nitrogen from protein to effectively ferment fibrous feeds.
A protein deficient diet may occur where very low quality forages such as mature grass hay, straw or crop stubble are used as the basis of the diet.  Lactating mares and growing horses are those most likely to experience a protein deficiency.  Where possible to avoid a protein deficiency try to feed a combination of low quality forage such as mature grass hay with a higher protein forage or high fibre feed such as lucerne hay or copra meal.  High protein feeds such as soybean, faba bean, lupins, chickpeas, rice bran, copra meal, brewers grains, canola meal and pollard can be added to the diet to provide a source of protein to help prevent a protein deficiency and to maintain effective fermentation of fibre in the hindgut.


Your horse's vitamin and mineral requirements must continue to be met throughout the drought.  In fact, it is perhaps more important than ever that during a drought that you satisfy your horses requirement for vitamins and minerals.  There two reasons why this is so important.  The first is that the quality of feeds available to you during a drought will often be low.  Forages such as mature grass hay and straws are virtually devoid of vitamins and have a low and variable mineral content, so during a drought is when your horse will most likely experience a vitamin or mineral deficiency.  The second reason why supplementation is so important is that a vitamin or mineral deficiency may reduce the efficiency with which your horse can digest and utilise energy from the diet.  Any reduction in feed use efficiency will mean you have to feed more to keep weight on your horse, which is definitely something you need to avoid when feed supplies are so limited.

Feeding any of the Mi-Feed range of feeds at the recommended rates will ensure your horses vitamin and mineral requirements are met, removing any risk of disease or reduced feed use efficiency associated with vitamin and mineral deficiencies.


Drought times expose horses to two major risks that are often not present during normal seasons. These risks are:

  1. Diseases associated with eating poisonous plants - because horses are often hungry and constantly search for food during a drought, you will find they eat plants that would not normally be eaten.  The RIRDC publication "Plants Poisonous to Horses: An Australian Field Guide" will help you to identify weeds that will cause toxicity and disease in horses.  The publication is available for purchase from RIRDC online at http://extranet.rirdc.gov.au/eshop/.
  2. Sand colic - because horses are grazing close to the ground and picking up more sand and dirt than normal, sand colic occurs far more frequently during dry periods.  If your horse is exhibiting signs of sand colic (colic, diarrhoea or losing body condition) feed 200 grams of psyllium husk per day for 5 days.  Repeat this routine once per month until your horses grazing conditions change.  Remember that dosing horses with oil will not relieve or solve sand colic problems.
  3. Mouldy or poor quality hay and chaff - as feed availability decreases, hay and chaff that would not normally be sold as a horse feed will make it onto the horse feed market.  While you may not have a lot of choice with the hay available, you will need to be extra vigilant in avoiding unsuitable hays that may cause disease, including colic in horses.
  4. Hay and chaff with a high grain content - as failed crops are baled for use as hay or chaff, you may find that the hay and chaff you are buying actually has a relatively high content of grain.  While this should not be an issue for many horses, you may find that horses prone to laminitis or those affected by cushing's disease will be adversely affected.  If you do have a horse that is adversely affected by grain feeding, be cautious with the hay and chaff you feed during the drought and try to select hay and chaff that has a low grain content.


As you head into this drought you need to realistically ask yourself if you can afford to keep and feed your horses for a prolonged period of time.  No-one knows how long this drought may last.  What we do know is that feed is in very short supply, which is and will continue to contribute to price increases such as the ones we have seen in the past few weeks.  If you don't think you can afford to feed and keep your horses in satisfactory condition through the drought you will need to find alternative arrangements for them.  As hard a decision this may be, it is definitely not acceptable to cross your fingers and hope for the best while you allow your horses to starve in the paddock.  Doing nothing is not an option!  You absolutely must put your horses' welfare above all other considerations.