Older Horses Part 1: Feeding older horses optimally

Feed management for older horses is a challenge. There are no set criteria that define a "senior horse" or the "older horse". The nutritional needs of older horses are different from those of adult horses due to changes in their metabolism and reduced digestive efficiency. The first step to a suitable ration for the senior horse is to determine whether the horse is a senior.

Is a 18+ horse a senior?  

There are three criteria for determining whether a horse is a senior or not, the first is chronological. Chronological means the number of years of life. The second criteria is physiological, which is determined by the vitality of the horse. In other words, to what extent the physiological functions, for example the kidneys and lungs, still work. The third and last way to determine the age is demographic. This is determined through the age of the horse relative tot he age of the entire population of the rest of the herd. This way is not important when putting together a ration.

There is no fixed chronological age from when a horse is considered a senior. Usually it happens at around 18-20 years. The chronological age is not enough to determine the nutritional needs of horses because there are large differences between aging horses. Two horses of the same age can have huge differences in vitality. This can happen for example because one of the two horses was sick or has a chronic disease. These horses therefore have the same chronological age but differ largely in physiological functions. To determine whether a horse is a senior you must take into account the chronologica lage, physiological status (vitality) and physical signs of aging.

Physical signs and age-related diseases of the older horse 

Every horse is an individual and undergoes different physical changes with aging at their own pace. As horses get older, they also undergo physiological changes which make them more susceptible to certain diseases. The most common physical signs of aging and common diseases in older horses are:

• Weight loss
• Loss of muscle mass
• Hollow grooves above the eyes
• Gray fur
• Dental problems
• Decreased bowel function
• A sagging back / sunken back
• Raid flanks
• Osteoarthritis / Arthiritis
• Behaviour change
• Equine Metabolic Syndrome (EMS)
• Insulin resistance (IR)
• Hoof captivity
• PPID (Cushing)
• Kidney and liver failure
• Greater chance of colic
• Changed hormone balance

Many physical symptoms are related to each other. For example, dental problems cause weight loss and loss of muscle. Also, horses with Equine Metabolic Syndrome (EMS) are more sensitive to Insulin Resistance (IR) and hoof attachment. It is best to adjust  the ration of the older horse before the horse gets complaints. To optimise the ration, the horse’s needs must first be determined.

Nutritional needs of older horses  

At this moment there is still little research conducted into the nutritional needs of older horses. This is difficult because there is so much variation between horses and the way individuals become older. Therefore there are no specific nutritional requirements established in the Livestock Feeding Table 2016, a book which is used in the Netherlands when calculating needs and rations for horses. Healthy old horses often do well on a ration compiled for the maintenance requirements of healthy adult horses. As the horse ages, the ability to digest food and the absorption of nutrients in the intestines decreases. As a result, these horses have a higher need for energy (EWpa), protein (Vrep), vitamins and minerals. Regardless of age, energy needs vary per individual. This depends, for example, on the way horses are kept. For example, whether the horses are in the stable, are outside with the weather and wind, and whether the horse is being trained. Some age-related diseases cause weight-loss, these horses have a higher energy requirement (EWpa). There are also indications that older horses are less able to digest crude protein (Vrep) so their protein requirements can be up to 12-14% higher. Essential amino acids such as tryptophan, lysine and threonine are important for older horses to maintain muscle mass.

Vitamins and minerals for older horses 

Less efficient digestion also means that a higher concentration of vitamins and minerals must be present in the ration. Adult horses can form vitamin C in the liver from glucose, while production decreases in older horses because the liver functions less. For older horses with health problems such as PPID and / or hoof seizure, a doctor recommends a ration with a constant limited sugar and starch content. With a low sugar and starch content, it is advisable to add vitamin C to the ration. Phosphorus requirements may be higher in older horses (0.4 to 0.65%), while calcium must be maintained at a maintenance level to maintain a Ca: P ratio of approximately 2: 1. Just like vitamin C, vitamin K is also formed in the horse's body. Vitamin K is not made by the horse itself but by the bacteria in the large intestine and cecum. Because the intestinal activity decreases in older horses, vitamin K has also been added to the Hartog 5 star Complete Care Senior. Senior horses need a lot of (easily) digestible fibers in their diet, these fibers keep the intestinal flora healthy and give the horse energy that is slowly released. To protect and support the stomach and intestinal flora, it is advisable to add Hartog Digest to every senior.

Water is the most undervalued part of every horse ration, and it is also essential for older horses. Water intake is especially important with older horses to prevent constipation. Rations for older horses should be based on the individual horse and specific circumstances such as poor teeth or age-related diseases.

Feed management for seniors 

The feed management of older horses largely depends on the condition of the teeth. Senior horses often have dental problems such as missing teeth, uneven wear or sharp points that make eating and drinking difficult and sometimes even painful. Want to know more about the teeth of older horses? The main goal of a ration is to achieve or maintain a healthy Body Condition Score, which helps prevent nutrition-related disorders and illnesses. As for any horse, the basis of the ration is roughage.

Roughage for older horses 

Horses require a minimum of 1 -1.5% of their body weight in dry matter from roughage per day. Senior horses need high quality hay with easily digestible fibers to compensate for their reduced digestion. Horses that have dental problems and can no longer eat (long-stemmed) roughage will have to be offered roughage substitutes. There are many different types of roughage substitutes for older horses on the market. Such as grass chunks, chopped roughage such as the Hartog Gras-mix, beet pulp or roughage in the form of Hartog 5* Complete Care Senior for seniors.

Tip! Food for old underweight horses: Senior horses are best fed separately from other horses so that they can eat undisturbed. Senior horses, especially those suffering from chronic pain due to arthritis, for example, are often submissive and less resilient and will be easily chased away when being fed by the more vital horses.

In the following article you can read more about how the dentures work: Older horses Part 2: The dentures: how do they work?