Practical Nutrition for Donkey Owners
By Shelagh Niblock, PAS
Everybody loves to see a donkey! With their large fuzzy ears and soulful eyes, they naturally tug at the heartstrings of horse lovers everywhere.
Donkeys were first domesticated in Africa around 3000 BC. They evolved in desert areas and, consequently, developed as browsers that can adapt to poor quality feed and irregular water supplies. Their easygoing nature and hardiness made them ideal as beasts of burden in the hotter, drier parts of the world. Coming in a variety of sizes, donkeys and their hybrid offspring, mules and hinnies, range anywhere from Miniature donkeys of less than 35 inches in height all the way up to Mammoth Jack donkeys that can exceed 15 hands.
Donkey Digestive Tract Basics
The digestive tract of donkeys is very similar to that of horses, but research has shown they use it much more effectively. They use the full capacity of their hindgut to metabolize the high fibre diets they are best adapted to, and this is the reason even donkeys of a heathy bodyweight always seem to have a pot belly. Utilizing their cecum and large intestine at full capacity results in greater retention time of feedstuffs in the hindgut, as well as greater production of volatile fatty acids (VFAs), the end products of the fermentation of fibre by the beneficial microbes. VFAs are transported through the hindgut wall to the liver, where they are converted to energy in the form of glucose. In the case of overfed donkeys, that energy from glucose may not be needed and is converted to body fat.
Chewing and dentition is important for any equid, but donkeys in particular need to have good teeth. All equids chew more when consuming high fibre feeds than low fibre feeds (see The Chew Factor – Fibre Intake in Horse Hay), but on similar diets donkeys consume feeds with less chewing than horses, meaning they can consume feed faster. If fed free choice forage, a donkey will consume more feed per kg of body weight than will a horse in the same period of time; consequently, dental health is very important for donkeys, and their teeth should be checked at least once a year by a veterinarian.
My Donkey is Getting Too Fat
Due to the lack of donkey-focused, peer-reviewed research into their nutritional needs, donkey requirements are loosely based on the National Research Council (NRC) 2007 Equine Nutritional Guidelines. The reality is donkeys are not the same as horses when it comes to nutritional needs, and it’s easy to see why in North America, where they are frequently kept as pets or companion animals, donkeys can fall prey to obesity. Donkeys need a high fibre diet with low non-structural carbohydrates (NSC). They are browsers and enjoy nibbling on hedgerows and blackberry bushes. They are also social eaters and eat far better when they can join their friends and stablemates.
Estimating Body Weight, Body Condition Score
It’s important when assessing your donkey’s ration that you have a good idea of their body weight (BW) and body condition score (BCS). The use of weight tapes designed for horses and the Henneke Body Condition score, designed for BCS assessments of horses, is not ideal for donkeys. The Donkey Sanctuary in Devon, England is one of the leading authorities on donkey husbandry in the world, has saved the lives of thousands of donkeys through their network of shelters, and is in the forefront of generating and funding research into the care of donkeys. They have published donkey appropriate BCS assessment charts as well as weight evaluation charts. To use these charts, all the donkey owner requires is a soft cloth tape measure for a heart girth measurement and a measuring stick for assessing height in centimetres or inches. Having an accurate assessment of height and BCS is critical for assessing the suitability of your donkey’s diet. The donkey BCS chart will help the owner evaluate the amount of body fat on the donkey on a scale of 1 to 5, with a score of 3 being considered an appropriate BCS. As it can be both risky and difficult to safely remove body fat from a donkey through dieting, maintenance of a healthy body weight is always recommended.
DONKEY BODY CONDITION SCORE CHART
Accurate body condition scoring is a hands-on process for feeling the amount of muscle and fat that are covering the donkey’s bones. Using this chart as a guide, feel the coverage over the bones in five specific areas listed below. Fat deposits may be unevenly distributed especially over the neck and hindquarters. Some resistant fat deposits may be retained in the event of weight loss or may calcify (harden). Careful assessment of all areas should be made and combined to give an overall score. When deciding on the correct course of action following condition scoring, you might have to take into consideration the age of the donkey and any veterinary conditions they have. Aged donkeys can be hard to condition score due to lack of muscle bulk and tone, giving thin appearance dorsally with dropped belly ventrally, while overall condition may be reasonable. If in doubt, get advice from your vet.
Specific Nutrient Needs
Just like horses, donkeys have a need for water, energy, and protein, along with vitamins and minerals. Estimates of the requirements of donkeys for specific nutrients are based on the NRC Equine Nutritional Guidelines. However, because of their more adaptable and efficient digestive tracts, donkeys are not the same as small horses when planning their rations. There are some general considerations to be aware of when planning your donkey’s ration:
Water — For any equid, water is one of the most important nutrients and donkeys are no exception. Essentially, they have the same water requirements as horses per kg of body weight, but they are more thirst tolerant and will continue to eat for longer in situations of reduced water intake. However, care must be taken not to confuse the donkey’s greater tolerance for thirst with their long-term need for water. As browsers who do best on a diet of low-quality forage, sufficient water is essential for donkeys to ensure they don’t fall prey to impaction colic.
It is important to be aware of donkeys’ sensitivity to water temperature, as they will drink less water that is too cold (less than 15 degrees C); this is especially so with seniors. Consider a heated water bucket in the winter so they don’t back off water intake.
Having evolved in desert areas with poor quality forage and scarce water, donkeys developed an efficient and adaptable digestive tract that must be considered when planning their rations. Photo: AdobeStock/PawelUchorczak
Related: Donkeys Feel the Cold
Energy (Carbohydrates and Fat) — Donkeys need complex carbohydrates in the form of fibre for energy. They must have low NSC (less than 15 percent) feeds for best health. Often a diet of straight C3 or “cool season” grass hay like timothy, orchard grass, or brome, even if it is of poorer quality, will lead to a fat donkey. Donkeys can manage very well on diets that are up to 75 percent cereal straw, with the balance being a medium quality grass hay and low NSC mineral supplement. As a matter of fact, the best way to make sure energy needs are being met for your donkey without overfeeding is to offer free choice straw, preferable barley or wheat straw as oat straw can be higher energy. Balance that with a medium quality grass hay weighed to equal about 25 – 50 percent of their diet, depending on the circumstances.
Donkeys love to browse, but if you are concerned about your donkey getting fat be cautious about turnout into spaces where no grazing but plentiful browsing is available. The amount of tender green blackberry shoots and leaves an enthusiastic donkey can consume in one hour would surprise you.
If your donkey needs to gain weight, it can generally be accomplished by increasing the percentage of grass hay in the diet. Donkeys having trouble with feed intake and BW maintenance because of other health issues may be supplemented if necessary with forage cubes or pellets, or low NSC manufactured feeds. Be sure to monitor their weight if feeding concentrates even if they are low NSC.
Donkeys can safely consume fats, but supplements containing extra fat should only be necessary for the geriatric donkey with poor teeth, or the sick or emaciated donkey. Any fat supplements offered to a donkey needing extra calories should be from a low NSC source. Feeding supplements to donkeys should be done following the same guidelines as those of feeding fat to horses. Be very cautious about the total amount of fat in the diet; start with a small amount and work up if necessary. Above all else, keep the meals very small and well-spaced throughout the day. If vegetable oil is fed, it should not exceed a total of 150 ml daily fed over at least two meals. If 100 ml or more of vegetable oil is given, 100 to 150 IU of supplemental Vitamin E should also be fed.
Mules possess the same feed efficiency as donkeys and their ration should follow similar guidelines. Photo: AdobeStock/FreeReinDesigns
Protein — Research from the Donkey Sanctuary UK for feeding donkeys suggests that if you have balanced the ration for energy, then the protein provided will generally be adequate as well. Donkeys are very efficient protein utilizers. If your donkey is looking like he/she needs to gain weight, then increasing the proportion of grass hay in the diet will not only increase energy but will increase protein as well.
Pregnant, lactating, growing, or senior donkeys may have a need for more protein intake or better-quality protein, but that can often be accommodated by the inclusion of a small amount of soaked alfalfa cubes or pellets in the diet, or by providing supplements with targeted amino acid content.
Vitamins and Minerals — Any reasonable quality equine vitamin and mineral supplement manufactured for horses should be appropriate for donkeys when fed according to BW. Equine balancer pellets may not be suitable for a donkey because of the higher NSC and intakes required for efficacy. Be cautious about offering vitamin and mineral supplements in the form of molasses licks due to the higher NSC content. Believe it or not, donkeys can be very picky about what they eat and sometimes a mineral supplement, particularly a low NSC formulation, will be met with extreme indifference. It is inadvisable to assume your donkey is going to eat free choice minerals offered in a container on the ground, even if mixed 50/50 with loose salt. The best way to get a picky donkey to eat his supplements may be to mix them with a very small quantity of soaked timothy pellets or soaked alfalfa cubes. Donkeys should always have access to salt through the use of a salt block.
The average intake expectation for horses is about two percent of body weight in dry matter intake per day. This means that your 500 kg horse can be expected to need approximately 10 - 11 kg of dry food per day. Donkeys on the other hand do very well with an intake of about 1.5 percent of body weight, and even at that a diet of grass hay only may result in an overweight donkey. The key to successfully feeding donkeys of any size is choosing the right hay and including straw as at least part of the diet.
Related: Feeding Donkeys
Senior donkeys with reduced ability to eat coarse forage may need to be fed chopped straw or additional hay. If more protein is needed the senior can be given a small amount of soaked alfalfa cubes or pellets. Photo: Shutterstock/Quercus1
Senior donkeys still need similar nutrients to younger mature donkeys, but the reality of aging teeth may reduce their ability to eat coarse forage and/or straw. Providing them with additional hay can help, and offering chopped straw, instead of long straw, may also be useful. Commercially available chopped straw is generally at your feed dealer, and you can feel at ease providing it free choice to your senior donkey. Senior donkeys that are still thin even with greater intake of grass hay can also be offered forage substitutes, such as alfalfa cube, timothy pellets, or low NSC feeds manufactured for horses with metabolic issues. The inclusion of small amounts of higher fat feeds, such as rice or ground flax, may also be helpful for seniors. As mentioned above, Vitamin E should be supplemented in donkeys fed supplemental fat.
Growing donkeys need to be fed adequate energy diets that allow them to grow at a consistent rate. Rations that are excessively high in energy for part of the year and deficient in energy at other times will not allow for healthy growth. Growing donkeys need a good supply of minerals calcium, phosphorous, magnesium, and trace minerals to avoid the development of orthopedic problems. Donkeys attain their mature stature by the time they are two to three years old.
Growing donkeys need consistent diets of adequate energy as well as calcium, phosphorous, magnesium, and trace minerals. Photo: Shutterstock/Montenegro
Potential Health Issues of the Overweight Donkey
Donkeys kept as pets and companion animals in Canada and the US are frequently overweight. Just like their horse counterparts, obese donkeys are more likely to get laminitis, arthritis, and metabolic issues like equine metabolic syndrome (EMS) and or pituitary pars intermedia deficiency (PPID). Growing donkeys that are allowed to become obese are more likely to have developmental orthopedic issues. Caution is needed if “dieting” an overweight donkey, as an extreme reduction of feed and energy intake may result in the metabolic condition “hyperlipemia.” Horses and donkeys placed on strict reducing diets will start to mobilize body fat reserves. The mobilized body fat travels in the blood plasma to the liver where it is converted into energy sources the tissues can use. However, donkeys, ponies, and Miniature horses can mobilize too much body fat too quickly, especially if they are obese, potentially overwhelming their metabolism’s ability to convert it into a safe form of energy. Excessive amounts of fatty acids in the blood plasma can cause damage to the tissues in the body, particularly the liver, and may result in death.
Weight loss in obese donkeys is best achieved with a reduction in hay and an increase in the proportion of free choice straw. Exercise is an excellent way to help the overweight donkey lose weight. Hand walking works well and the use of toys can be helpful for the young donkey. Expect it to take at least four to six weeks or more in extreme cases to see any significant difference in body weight. Beware of increased turnout for the obese donkey if there is weedy growth along fencelines or in paddock areas; if there is any edible browse, you can be sure a donkey will find it.
Above - This overweight donkey has a BCS of 4. Photo: iStock/DriftlessStudio
EMS, PPID, Laminitis
Donkeys are very susceptible to all the metabolic issues that can affect horses. Pharmaceutical treatments for the metabolic conditions PPID, EMS and insulin resistance (IR) are the same for donkeys and horses. Consult your veterinarian for diagnostic tests and possible pharmaceutical options for donkeys with metabolic diseases. Probably the most important considerations for these donkeys are diet, body weight, and body condition score.
Hoof health issues can be more prevalent in donkeys than in their horse counterparts, especially in overweight donkeys, with laminitis and white line disease of particular concern. It’s important to have regular farrier attention for your donkeys.
Mules and Hinnies
This working donkey is in excellent condition. Photo: iStock/Igor Alecsander
Mules and hinnies are the hybrid offspring of a mare and jack (male) donkey, or a jennet (female) donkey with a stallion respectively. Both mules and hinnies tend to be vigorous, healthy animals, with excellent ability to work and thrive in harsh conditions. In general, mules possess the same feed efficiency as donkeys and should be fed following similar guidelines. In North America, mules are less often kept as pets or companion animals and more often as working animals. As such, they need a diet with a higher energy density than most donkeys. When assessing the ration of your mule or hinny, utilize BCS charts to ensure they are not gaining excessive weight and adjust feed energy levels according to the amount of work they are doing. Like donkeys, the use of high NSC feed stuff like sweet feed, even in the diets of working mules, is generally not advisable. Working mules can frequently enjoy a diet with a higher quality forage and less straw that their non-hybrid counterparts.
These donkeys are at a healthy weight with an ideal BCS of 3. Photos: (top) Canstock/Macrolife; (bottom) Adobestock/Klodien
Planning Your Donkey’s Ration
How do you create a great ration for your donkey? Start off by assessing body weight and BCS. Calculate 1.5 percent of your donkey’s healthy BW, then take that number and multiply by 25 percent. The result is the amount of grass hay your donkey gets. For the balance of his diet feed free choice straw. Over time, adjust the proportions of hay relative to straw as required to ensure an adequate energy diet.
Ideally, straw should be fed on the ground. According to research done by the Donkey Sanctuary UK, they usually leave some behind and may even lie on it. Keep the feeding area well stocked with fresh, free-choice straw, removing the old straw regularly and recycling it as bedding for your donkey.
Straw should be available free-choice as part of the donkey’s diet and fed on the ground. Photo: AdobeStock/Susy
Mineral supplements can be offered daily in a very small meal of soaked cubes or timothy pellets. Avoid balancer pellets for donkeys as the intake necessary may be too high in energy for them. Donkeys should not be given feeds with an NSC of over 15 percent on a dry matter basis.
Provide tepid water in the wintertime as donkeys can be susceptible to impaction colic; if the water is warmer, donkeys will drink more.
Monitor your donkey’s BCS carefully for weight gain or loss and adjust hay accordingly. Be cautious about turning donkeys out to browse as they may find high energy vegetation you didn’t even know was there.
And finally, ensure your donkey gets some exercise. Hand walking, driving, or even the use of toys can be helpful.
A family of healthy feral donkeys near Death Valley National Park. The park straddles the California-Nevada border and is the hottest and driest national park in the US. Photo: AdobeStock/Angeldibilio
Donkey enthusiasts in Canada have two excellent resources to consult on the care and husbandry of their donkeys. The world leader in donkey information is The Donkey Sanctuary in Devon England. The Donkey Sanctuary has initiated some excellent peer reviewed research on donkey behaviour, health, and nutrition.
The Donkey Sanctuary of Canada is located in Puslinch, Ontario. Modelled after the original Donkey Sanctuary in the UK, it is a registered charity that has offered sanctuary to literally hundreds of donkeys in Canada.
Even if you have always loved donkeys but have never been able to own one, you can still support research into better methods of looking after them by supporting the above-noted groups. If you do own a donkey, both these groups would love to hear from you.
Related: Donkeys are Natural Heat Lovers
Main Photo: Shutterstock/Dietrich Leppert