In this issue Dr Tom Shurlock, consultant nutritionist for British Horse Feeds talks us through providing the right kind of energy and oil for the competition horse.
Energy is a simple term for a complex and multi-faceted metabolic and biochemical interaction. Energy provides heat to maintain body temperature, chemical reactions to utilise nutrients and drive physiological activity; in short, to provide life.
Different food types have different energy, measured in calories, or joules. This is because gross energy is a measurement of the heat released when combusted, and oil provides more than carbohydrates or protein.
When it comes to equine nutrition, oil – alongside fibre – has been referred to as slow-release energy. This is a misleading term but it highlights a biochemical difference between starch/sugar and oil/fibre as energy sources.
Central to energy generation for activity is the production of the metabolite ATP which fuels muscle contraction, through a pathway called glycolysis and the TCA cycle. Glycolysis releases ATP to power the anaerobic activity (fast release), whilst the TCA cycle powers endurance and aerobic action. Oil, protein and fibre metabolites enter this mechanism at this stage; referred to as “slow release”.
The major advantage of oil is that it is the main storage form. Some ingested sugar is converted to glycogen, any extra is converted to fat, as is excess oil. These reserves are than used if dietary intake of energy is less than that expended.
Oil as part of the diet can substantially increase energy intake to aid the competition horse, as well as reducing the reliance on starchy feeds.
Although some sugar is essential for energising the brain, and anaerobic function – background levels are usually sufficient, so using high energy fibre sources (super fibres) and oil can supply sufficient energy for enhanced muscular activity.
As mentioned before oil has the highest energy of any nutrient group, but this is dependent on its ability to be absorbed into the body. Those high in omega-3 and omega-6, have greater digestibility than more saturated oils and long chain fatty acids more so than shorter chained.
So although a novel oil, such as coconut, may have other beneficial effects metabolically, long chain polyunsaturated fatty acids (PUFA), linseed in particular, have a greater digestibility and so provides more digestible energy.
Choosing the right Energy Source
Formulating a diet that partitions energy into various sources, and takes into account their relative digestible energies, enables the horse’s potential to perform.
It is not just a matter of energy. Protein, fibre, minerals and micronutrients are also essential, but choosing the correct energy sources and combinations can impact positively on performance.
Using an ingredient rich in the best nutrient profile – not only oil but the other nutrients – can be a simple, effective and versatile option for the various phases of an active season.
However, the digestible energy of an oil is not the only aspect of fulfilling the athletic performance of the horse; the profile of the fat itself is an important factor.
Oil consists of individual fatty acids linked to a molecule of glycerol. Where there are three, we have triglycerides, but there are also combinations with phosphates, polar entities, sugars etc. occupying some of the glycerol sites, giving a whole range of oil types.
Additionally, there are the different fatty acids, both in terms of chain length and the position of the unsaturated bonds. PUFA are a varied class of fatty acids, within which they have supportive function in the active horse.
Omega-3 is a base for the generation of many metabolic substances, some of which support muscle recovery, improve insulin sensitivity and improve energic performance.
Omega-6 is essential for good vascular integrity, whilst omega-9 supports muscular activity.
Most PUFA oil sources have high proportions of omega-6, and there is a need to redress these levels with an omega-3 option.
For the competition horse there is a need to balance energy sources, but also to make the system flexible and easy to adapt to changes over the season. Providing a diet where the majority of energy comes from fibre sources is in the best interests of the horse; added starch and sugar – within sensible limits – would cover essential needs, and a source of omega-3 rich oils is the final part of the puzzle.
The energy levels can be altered to adapt to different activities, but there will be a supply of additional support for recovery, muscle activity and reduction of oxidative stress. Provided in a high protein ingredient, both for ease of use and to support muscle development, a high omega-3 PUFA, with polar lipid properties is potentially the best supplement for a performance horse.
Cooked Linseed is an ideal product. With 39% oil, almost a half of which is as omega-3 fatty acids, it provides a protein source rich in components that help maintain musculature and recovery, and an ease of feeding. Cooked Linseed provides the energy, simplicity and versatility of a complementary feed for the competition horse.