Can I feed something for weight-gain without giving energy?
In short – No!
Weight gain requires calories, calories = energy. So it’s nigh on impossible to have one without the other.
However energy isn’t necessarily a bad thing – it doesn’t have to mean bad behaviour.
What energy source do I use?
There are four main sources of energy in the horse’s diet; fibre, sugar, starch and oil.
Fibre is very important in the diet; two-thirds of the horse’s digestive tract is devoted to fibre digestion, while just one-fifth is designed to process starch from cereals, oil and protein!
The vast majority of horses will sustain well on high fibre diets, but harder working horses will often require more energy/calories than fibre can provide. This is where sugars, starches and oil can be used instead.
Starch is primarily provided by cereals (mixes) and are more commonly known as being ‘quick release’ energy sources, this is due to the speed at which they’re digested. Providing cereals aren’t fed in high quantities, meaning undigested starches don’t flow into the hindgut and cause issues (from excitability to ulcers) they can be a useful energy source.
Sugars are often avoided like the plague and although very high levels can cause silly behaviour, most compound and fibre feeds contribute very little sugar to the diet (even when they have added molasses). Grass on the other hand can contain up to 50% water soluble carbohydrate (sugar + fructan, the storage form of sugar in grass), plus the same amount of energy as a racing mix on a kilo for kilo basis! So rather than worrying too much about feeding ½ scoop of molassed chaff, if your horse is getting a lot of good grass that could easily be the cause of a bit of over exuberance!
Oils are often considered a safer source of energy for horses, due to being low in starch and less likely to cause any digestive upset. Plus they contain almost double the level of energy that cereals and fibre can provide, this means they can be fed at a lower rate; ideal for fussy horses or those that struggle with big bucket feeds. The digestibility of oils is also higher than that of cereals, meaning horses can extract energy from oils more easily.
However feeding oil isn’t quite as simple as popping to the shop and whacking some cheap vegetable oil into your shopping basket, not all oils have the same benefits and even the correct ones need to be balanced with the right amount of Vitamin E.
What about protein?
Unfortunately it has been cast as a bit of a villain in the feed world, but actually protein is important in any horse’s diet. The building blocks of protein are amino acids and these are particularly useful in muscle growth and development, particularly in young stock.
Due to the requirement for protein levels to be displayed on feed bags, but not starch levels – protein has often been wrongly blamed for various problems and has been used as an indicator as to the ‘richness’ of some feeds. In fact, protein is rarely used as an energy source for horses and it has also come to light that protein is not to blame in cases of laminitis, ERS and excitable behaviour.
So what should I do?
Primarily stick to high fibre feeds, if you require energy – look at oil-based calorie sources! If you have starch sensitive horse, avoid mixes even if they claim to be ‘non heating’. Don’t panic too much about molasses, starch is more important to avoid in terms of excitability.
Be aware of ‘calming’ feeds as these are often high in added magnesium which can cause unpredictable and spooky behaviour.