Nutrition CPD April 2017

60

Feeding performance veterans

By Kate Hore RNutr (Animal), senior nutritionist at NAF

If horses are kept fit and active, there’s no reason why their competitive life shouldn’t extend well into their 20s.

Older horses in the UK

Without doubt, the equine population in the Western world, including within the UK, is ageing. 

One study in the US found that while horses over 20 years of age represented just 2% of admissions to a referral veterinary hospital in 1989, by 1999 this had risen to 12.5% and around 20% by 2003. 

Similarly, surveys within the UK find about 30% of horses to be over 15 years old, with 11% being between 20 and 30 years, and 2% over 30 years of age. 

The reason for this change is likely to be twofold. In part, more people keep horses purely as pets, and are happy to commit to keeping that horse or pony well into old age. And partly the improvement over the years in nutrition knowledge, routine use of efficient anthelmintics and improvements in equine dentistry have all contributed to horses living happily and healthily into their twenties and beyond. 

However, that doesn’t mean we’re growing a population of equine retirees – far from it! As improvements in equine health continue, so we find that horses maintain fitness through their teens and well into their twenties. 

A study in 2001 found that while 61% of owners of veteran horses did report that the intensity of the work might decrease, the majority of older horses were still in regular ridden work, and 21% were still actively competing at a median age of 18.

Advances in human health tell us that keeping fit and active throughout your life, and maintaining that activity into older age, helps us keep healthy into older age, and the same is likely to be true of horses. So what can we do from a feed and dietary point of view to help maintain our OAPs? That’s Old Age Performers, of course! 

Feeding the veteran

It’s traditionally thought that older horses will suffer with reduced absorption and digestibility of the diet, and so struggle to maintain condition. Therefore their diet needs to be changed accordingly. 

It’s now considered that thinking is somewhat out of date, dating back to horses born in the 1960s and 70s who had not had the advantage of modern diets and wormers throughout their lives. Now we find that ageing itself does not significantly affect digestive efficiency in horses until horses become decidedly geriatric, and not just older. 

A recent study at CAFRE, Co. Antrim found that maintaining bodyweight (BW) and Body Condition Score (BCS) does not become an issue until an equine is in their late twenties (27 +). In fact, just as with younger horses, a high BCS should be avoided as it may exacerbate health concerns (see Keeping Sound, below).

The advice to owners of older horses, therefore, should be to certainly regularly review BCS and diet as the horse ages, but so long as the horse is maintaining condition and working well, then no radical changes are required. For those horses who do need a little help, ensure the diet stays fibre based but consider short chop fibres or cubed hays which are more easily digested, especially when soaked. 

For performance veterans the addition of oil to a fibre diet provides an ideal form of energy. Easily metabolised by the horse and non-heating, oils - such as linseed or soya - are a useful energy source. Just remember if feeding at significant levels for energy, the high oil diet should be balanced with supplementary vitamin E. 

Gut health

One area where it is worth considering supplementary support is in gut health. Gastrointestinal conditions, such as colic, are a major concern in older equines. A 2009 study in the UK found colic second only to musculoskeletal issues for reasons for mortality in older horses. 

It is recommended to balance the diet with a concentrated balancer, providing live probiotic yeasts and prebiotics, to support a healthy microbiota (microbes including yeasts, fungi, bacteria) of the hind gut.

Concentrated balancers are formulated to include the essential micronutrients, such as vitamins, minerals and trace elements, to balance the fibre based diet. 

Keeping sound

Musculoskeletal conditions, particularly lameness and osteoarthritis, are consistently found to be the biggest concern in older horses. In one study at a UK equine charity, the average age of euthanasia was 20, with 66% of those being due to osteoarthritis. So it represents a challenge for owners who wish to keep their older horses performing. 

Of course, the joints of performance horses undergo stress as part of normal work, but that is not the whole issue. It is thought that horses, like humans, show evidence of ‘inflamm-ageing’, that is, a raised pro-inflammatory state within the system which comes from higher levels of those cytokines (cells of the immune system) involved in inflammation, including interleukins, interferons and TNF-α (Tumur Necrosis Factor). 

As obesity also increases circulating pro-inflammatory cytokines, this is a principle reason why all horses - including older horses - should be kept ‘fit not fat.’

To maintain joint health in older horses, it is recommended to feed a good quality joint supplement. With the huge choice available it can be difficult to know which to advise. Ensure any joint supplement provides a significant level of glucosamine sulphate, which research shows is the most efficient form of glucosamine. 

However, thanks to the research advancements in molecular biology, we know that joint stress is a very complex multifactorial condition. Multifactorial problems require multifactorial approaches – one size (glucosamine) cannot possibly fit all. Look for a supplement where glucosamine is combined with other key nutrients including MSM, chondroitin sulphate, HA and specific antioxidant groups, all of which have been shown to work synergistically with glucosamine when in the right combination. 

For older horses, or simply older joints in particularly hard working horses, look for a supplement designed for that specific life stage. Supplements for older joints are likely to include the key joint support nutrients, but also omega 3 fatty acid which not only has a role in inflammation but also in heart and brain health. 

To summarise

In conclusion, by keeping horses fit and active, monitoring any BCS changes and ensuring gut and joint health are supported, there is no reason why the competing life of performance horses can’t extend well into their twenties and beyond.