Appropriate nutrition is a key component for successful behaviour management of ‘hot’ and anxiety-prone horses. It is important to consider the forage to hard feed ratio, total caloric intake, amount of starch or sugar in the diet and critical mineral ratios. Nutraceuticals to aid in management of mycotoxins and to maintain a healthy microbiome can also have a significant impact on behaviour.
How much hay do I need to feed?
The amount of hard feed your horse needs is influenced by the quality and availability of pasture for grazing as well as horse size, level of activity or breeding status and his or her individual metabolism.
Roughage (also called forage) forms the foundation of all good horses diets and includes grass, hay, silage and chaff. Horses need roughage weighing a minimum of 1 per cent and preferably closer to 2 per cent* of his or her bodyweight measured by dry weight. [* The 2% forage rule applies to horses needing to gain or maintain weight. It may not apply to overweight or insulin resistant horses.]
A 500 kg horse without pasture access needs around 10 kg of hay, predominantly grass or meadow hay. The more grass available for grazing, the less roughage needs to be fed. Learn to monitor your pasture’s availability; be aware that paddocks with large over-grazed sections and smaller patches of mature grass are not likely to provide enough forage.
The amount of hay required will changes depending on daylength, rainfall and temperature. You can check whether your horse is getting enough forage by offering good quality grass or meadow hay. If your horse eats it all, keep increasing the amount of hay fed each day until your horse is leaving just a little, then decrease slightly.
Limit lucerne and clover to no more than 20 per cent of forage intake. Some ‘hot’ horses may react to high protein diets so observe carefully how much lucerne or clover forage and legume grain your horse can tolerate.
Ensuring enough roughage is the best starting point for designing a good diet for a ‘hot’ horse. Horses who hold condition easily may only need a mineral balancer pellet or powder to complete their diet of grass and/or hay.
If your horse does not hold weight when allowed free choice access to grass or grass hay, add calories with a hard feed low in sugars and starch.
Which hard feeds are best for ‘hot’ horses?
You don’t have to use pre-mixed feeds with the word ‘cool’ in the name to provide a nutritious diet capable of keeping your ‘hot’ horse in good condition without losing his or her cool. In fact, some feeds marketed under the name ‘cool’ are very high in starch and cereal grains which are actually ‘heating’ ingredients!
The best source of additional calories to keep condition on a ‘hot’ horse are those with a low glycemic index (GI). The glycemic index measures the rise in blood glucose levels two hours after eating that food. High GI foods such as cereal grains like barley, oats and rice are rich in sugars and simple carbohydrates are generally considered ‘heating.’ Feeds with added sugar/molasses/honey are best avoided in a ‘cool’ diet.
‘Cool’ feeds have a low GI value and are low in sugars and starch. Read the label on premixed feeds carefully and choose feeds made from the following ingredients or make your own feed by combining 2 – 3 from the “Cool Feeds” list.
Cool Feeds List
Super Fibres – high in digestible fibre
- Beet pulp
- Legume hulls (e.g. soy, lupin, chickpea hulls)
Legume Grains – high in fibre and resistant starch
- Mung beans
- Soy beans
* Soy beans, chickpeas and mung beans should not be fed raw. They must be processed through a controlled heat treatment to improve digestion and bioavailability of nutrients. Lupins may be fed cooked or raw, but whole or cracked lupins must be soaked until soft.
Oils – energy dense, no carbohydrates
Fatty Acid Balance
Oil is very calorie dense and can be used to boost the energy intake of underweight and hard-working horses without increasing the size of the hard feed. Oil can be fed at up to 1 ml per kilogram of horse bodyweight provided it is introduced very gradually and vitamin E intake is increased by 1.5 IU per millilitre of oil but common usage is within the range 50 to 250 ml.
Although any plant-based oil can be used to provide ‘cool’ calories, many are extremely high in omega-6 polyunsaturated fatty acids. Since horses need to consume more omega-3 fatty acids than omega-6, the type and amount of oil used must be chosen carefully with consideration to the roughage source.
Horses grazing plentiful green grass have an omega-3 rich diet. The more hay and grains fed, the higher the omega-6 intake. Horses on high omega-6 diets should avoid oils with an omega 3 to 6 ratio of less than 1. Oils and oilseeds with an omega 3 to 6 ratio above 1.0 include linseed, chia and blends of canola with fish or algal oil.
Horses with particularly sensitive stomachs or suffering chronic stress can benefit from ongoing omega-3 supplementation regardless of diet.
Research shows that marine-sourced omega-3s (DHA and EPA) can improve cognitive function in humans. DHA is essential for normal brain development before and after birth. EPA is linked to mood and behavior. Perhaps in future we will see research linking marine-sourced omega-3 supplementation (DHA and EPA) to improved horse behavior and learning!
Farmalogic Omega Balancer is a palatable and stable omega-3 supplement which is even more potent and effective than linseeds or linseed/flax oils due to the DHA/EPA content from marine-sourced omega-3.
How much hard feed should I feed?
Feed the smallest amount of hard feed required to maintain a healthy weight. Split the daily allowance into multiple small meals across the day to prevent microbiome disruption, hindgut acidosis and the reduce the risk of colic. For a 500 kg horse, a hard feed should not exceed 2 to 3 kg dry weight.
Consuming too many calories, even from ‘cool feeds’ can make a horse feel playful! Adjust the amount fed regularly in response to changes in work level and forage quality.
Gut health and ‘hot’ horses
Anxiety and stress are detrimental to gut health, and poor gut health exacerbates ‘hot’ behaviour. ‘Hot’ horses usually benefit from extra care for good gut health as well to avoid the downward spiral caused by painful gut issues such as gastric ulcers, hindgut acidosis and dysbiosis (disrupted gut microbes).
Horses rely on a healthy gut microbial population to produce butyrate (a calm energy source with gut healing properties) and many B-group vitamins. Vitamin B deficiency can reduce appetite, affect the nervous system and influence behaviour.
A healthy microbiome reduces the levels of lactic acid and maintains a more stable hindgut pH which can reduce the impact of stress on the gut and avoid potentially behaviour-modifying deficiencies.
Scientists found that horses fed live yeast probiotics (Saccharomyces cerevisiae) prior to a stressful event had measurably lower stress hormone levels and their gut flora returned to a normal healthy state faster than unsupplemented horses.
Supplementation with Farmalogic Rejuvenate containing the live yeast Saccharomyces cerevisiae helps maintain the natural diversity of hindgut bacterial populations and is a useful strategy in the management of ‘hot’ horses.
Vitamin and mineral supplements for dietary balance
‘Hot’ behaviour can be caused by inadequate vitamin B levels or mineral imbalance. Providing nutrients to overcome nutrient deficiency can impact positively on behavior, but overfeeding can cause imbalances that may be harmful.
Horses with a ‘hot’ temperament often benefit from supplementation with B-group vitamins.
All horses need to have microminerals added to balance their diets (especially copper, zinc, selenium, iodine). The correct balance of calcium, phosphorous and magnesium is important for muscle contraction/relaxation and normal brain and nervous system function.
Vitamins and minerals can be supplemented by providing the full recommended amount of a quality pre-mixed feed, or by adding the appropriate Equine Vit&Min balancer powder or pellet to meet your horse’s needs. When feeding a reduced rate of pre-mixed pellets or muesli, use a balancer powder to top up and balance your horse’s vitamin and mineral requirements. Remember that it is possible for a horse to be deficient in one mineral even if the recommended daily intake is provided if mineral ratios are unbalanced.
Pasture-related behavioural changes
Sometimes pastures can contribute to changes in behaviour as a result of mycotoxin contamination, mineral imbalance, the presence of phytoestrogens and high sugar levels which can cause hindgut acidosis.
Mycotoxins are harmful substances produced by bacteria and fungi that grow on forage and grains. They can be present in pastures and hay as well as in grains or hard feeds. Mycotoxins can negatively impact gastrointestinal function and cause damage to the brain, nervous system and other organs. Symptoms of mycotoxins affecting the nervous system may include unpredictable, irritable or spooky behaviour and separation anxiety.
Clover, subclover and some kinds of mycotoxins contain phytoestrogens which mimic the sex hormone estrogen and can cause ‘marey’ behaviour and fertility problems.
Very lush grasses from highly productive species (e.g. ryegrass and clover) contain high levels of sugar, potassium and nitrates especially during spring and autumn. Horses grazing these pastures may need extra salt and magnesium. Horses who become ‘hot’ on these pastures should have their access limited with strip grazing, grazing muzzles or removal from the area.
Management of pasture-related behavioural change may require feeding a mycotoxin binder supplement, limiting grazing hours or removing your horse from affected pastures during certain times of the year.