Ageing & nutrient digestibility

Research published in 2014 found that in healthy horses, ‘being senior’ did not affect energy, protein or NDF (fibre) digestibility regardless of the type of diet fed (hay only, hay plus a starch and sugar based feed or hay plus a fibre and oil based feed). A follow up study showed that age had no effect on mineral digestibility. This suggests that age per se doesn’t affect nutrient digestibility, at least for horses and ponies fed an appropriate diet.

Ageing & gut bacteria

The horse’s hindgut is home to trillions of tiny microbes including bacteria, viruses and fungi which are essential for fibre digestion and helping to regulate the immune system. Research in healthy horses found that ageing led to a reduction in the diversity of hindgut microbes, which may make some older horses more sensitive to changes in diet. Interestingly, no reduction in diversity was seen when this research was repeated in similarly aged ponies. Although the reasons for this are not yet clear, these findings may suggest that ponies ‘age’ later than horses.

When do senior horses need a change in diet?
Provided their current diet is appropriately balanced, healthy horses and ponies with good body condition may not need any changes. The golden oldie or ‘true geriatric’ will show multiple signs of ageing and need more specialist management. Regular monitoring is key as feed and management requirements may change to over time.

Did you know? Senior feeds often contain higher levels of quality protein, vitamins and minerals. Although optimal requirements have not been established, seniors may benefit from a diet that provides the protein, vitamins and minerals required for work, even if they are retired. Some senior feeds also include added functional ingredients to help support digestive and/ or joint health.

Excess weight gain & obesity
Not all senior horses are prone to weight loss! Obesity carries a number of health and welfare risks for horses of all ages but may further exacerbate issues associated with ageing, including joint strain, difficulty regulating body temperature and chronic low-grade inflammation or ‘inflamm-aging’.

Weight loss

Senior horses may lose weight for numerous reasons so it’s important to ensure underlying clinical conditions, pain or dental issues can be ruled out. In healthy horses with good teeth, nutritional management should focus on providing as much forage as the horse/ pony will eat (while being mindful of excess waste) and supplying additional energy or ‘calories’ through appropriate feed.

Research has shown that feeding a meal high in starch and/or sugar may lead to an exaggerated insulin response, even in healthy senior horses. In practice, this means choosing feeds containing low or restricted levels of starch and sugar, which may be beneficial for all senior horses. Being proactive is by far the best strategy and allowing poor doers to enter the winter at a body condition score of 6/ 9 (provided they are not laminitic) may help to buffer excess weight loss.

Laminitis & PPID

Maintaining a healthy weight/ body condition and providing a diet low in non-structural carbohydrate (NSC) or ‘starch and sugar’ is key to managing horses and ponies at risk of laminitis, including those with Pituitary Pars Intermedia Dysfunction (PPID: also known as Cushing’s syndrome). Owners should always seek specific advice from a nutrition advisor, but general tips include:

• Restricting or removing grazing
• Analysing forage water soluble carbohydrate (WSC) and feeding soaked hay as a back-up
• Choosing fibre-based feeds that are low in starch and sugar
• Using feeds high in oil (as opposed to cereal starch) for those in need of additional calories – oil is approximately 2.5 times higher in energy (calories) compared to cereal grains and starch free
• Dividing feeds into multiple small meals

Weight monitoring

Ideally owners should monitor their horse’s weight weekly and body condition score fortnightly. While some loss of muscle often occurs with weight loss,it’s important to remember that body condition scoring is an assessment of fat, not muscle/topline. In general, muscle feels firm and fat feels soft but a loss of muscle mass in senior horses can sometimes be mistaken for a loss of body fat. Those with PPID may have regional fat deposits such as a large crest or fat pads on the loins despite being thin over-all – this can sometimes be mistaken for generalised obesity and lead to the diet being restricted too severely.

Muscle tone and topline

Many owners will tell you that their older horse has lost muscle tone, however these observations may not be a direct effect of ageing. A reduction in exercise has a larger effect on muscle tone than ageing per se. While some degree of muscle loss may occur with ageing, it may be caused or exacerbated by an underlying clinical condition such as PPID, injury or poor saddle fit so it’s important not to make assumptions. Owners should seek advice from their vet if they have any concerns, especially if there have been no obvious changes in diet or work as muscle wastage may be the result of something that could be addressed.

Dental issues

Dental issues, which include lost or worn teeth, diastemas (gaps between the teeth), inflamed gums and even arthritis of the jaw, can lead to weight loss and several digestive issues including choke, loose droppings and colic. While some dental issues can be resolved, management of those that can’t often relies on replacing some or all long fibre (grass hay and haylage) in the diet with a hay replacer. Those with very poor teeth may need 100% of their diet replaced with a mash.

Advise customers that are choosing/ feeding a hay replacer to:

• Check the energy (calorie) content - while some contain similar energy level to average meadow hay (around 8 MJ DE/ kg), others provide the same level of calories as a competition or conditioning feed.
• Choose hay replacers low in sugar and starch for those prone to laminitis and avoid grass-based products as they may be high in WSC.
• Where possible include at least some short chopped fibre to increase eating/chewing (short chopped fibre is unsuitable for horses with diastemas).
• Weigh mashes before soaking and check the soaking instructions carefully.
• Check whether hay replacer(s) contain added vitamins and minerals.
• Ideally divide into a minimum of four meals for horses without access to grazing
• Consider dividing rations between multiple buckets to help to encourage ‘grazing’.
• Separate the horse from companions at mealtimes to prevent ‘sharing’ or bullying if needed.

Sensitive teeth

Did you know having sensitive teeth may cause some seniors to be reluctant to drink very cold water (or eat feeds mixed/soaked in cold water)? Reduced water intake increases the risk of colic, particularly in stabled horses who are fed dry hay.

Joint disease

Pain from general joint disease can affect appetite and overall welfare so in these circumstances, owners should discuss a pain management programme with their vet.

Did you know that arthritis in the neck or forelimbs may make pulling hay from a net, grazing or lowering the head uncomfortable?

Advise customers to:

• Watch their horse’s weight – remember excess weight gain increases joint strain!
• Try offering feed, forage and water from raised buckets, mangers and troughs.
• Avoid stabling for long periods. Turnout provides gentle exercise but try to avoid uneven ground, heavy mud and paddocks on a steep incline, all of which increase joint strain.
• Look out for horses constantly found snoozing while others are grazing – this may be a sign that pain from chronic arthritis (or another underlying condition) means they feel unable to lie down and rest fully.

Appetite

A number of clinical conditions and dental issues can result in a loss of appetite so it’s essential to rule these out first. However, a change of routine or being separate from companions can make some seniors reluctant to tuck in to their feed or forage, while others simply become fussy with age.

Advise customers to try:

• Adding warm water feeds
• Choosing feeds with an added flavour or herbs
• Adding herbs, fruit juice, garlic, mint or fenugreek to their horse’s current feed (but always consider the risk of prohibited substances!)