Like horses, donkeys have served as work and companion animals for thousands of years. Today, there are an estimated 42 million domestic donkeys throughout the world. For comparison, there is an estimated 58 million horses found worldwide. Even in modern times, donkeys continue to be important for many people and cultures.

While both horses and donkeys are equids, they are different species. Horses (Equus ferus cabullus) diverged from both the wild ass and zebra lineages over 2 million years ago. Horses were first thought to be domesticated from wild Tarpan horses in the Western Eurasian steppe about 5500 years ago. Donkeys (Equus asinus) are thought to have been domesticated from the African wild asses nearly 6000 years ago.

The differences in how horses and donkeys evolved is important because it explains why donkeys differ from horses in many ways. This also explains why donkeys have different dietary requirements and can survive on feedstuffs not suitable for a horse. Yet, donkeys are equids and are very similar to horses in many ways, too. They are just as susceptible to feeding mismanagement and prone to dangers, such as equine laminitis and metabolic disorders.

What Are the Forage Requirements for Donkeys?

Since donkeys evolved from the wild asses in the arid regions of Africa, they have a greater ability to digest and extract nutrients from forage that is either higher in fiber or of a poorer nutrient quality. Many people liken them to goats, as donkeys can eat more mature and fibrous forage than horses. Overall, this just means donkeys have evolved to digest forage more efficiently than a horse.  

It is very important to remember this does not mean donkeys should be fed poor quality hay, especially one with mold or other toxins that can kill the animal. Rather, it means they usually do not require a nutrient-dense hay to maintain a healthy body weight or condition. Thus, nutrient dense forages, like our legumes (alfalfa, clover), should be avoided. Grass hays that are in a late-stage maturity would be an ideal choice. Alternatively, donkeys can eat and digest straw. However, like any forage, it should be of feeding quality and free from debris.

The amount to feed can vary depending on the donkey’s activity. When donkeys were given free access to forage, research showed that they will only consume about 1.5% of their body weight per day. For a medium-sized, 450-pound donkey, this would equate to about 7 pounds of forage per day. Conversely, horses with free access to forage will consume nearly 3% of their body weight per day. Thus, the ideal amount of hay a donkey should be given is recommended at 1.5% of their body weight per day.

With regards to feeding behavior, it is interesting to note that donkeys consume forage faster than horses. In one study, donkeys were observed to have a quicker chewing rate as compared to horses and ponies. Scientists attribute this to donkeys (wild asses) evolving to survive in arid regions where resources are sparse. They had to learn to eat quicker to survive. They also stated that donkeys appear to have developed a more efficient chewing mechanism with an ability to swallow larger feed particles as compared to horses. All in all, this adaptation has allowed them to consume as much feed as possible, as quickly as possible, to survive. Some owners use hay nets or find other novel strategies to help alleviate boredom and stretch out feeding times for their donkeys.

Finally, one may wonder how this impacts pastures and if donkeys should be allowed to graze unmonitored. The quick answer is no, it is not ideal with green and productive pastures. Generally, donkeys are kept under dry lot conditions and fed hay. However, some may allow donkeys limited turn out on pasture, and attempt to use grazing muzzles, or other limited grazing management strategies.

What Other Nutritional Support Do Donkeys Need?

While donkeys do differ from horses, they are still an equid. They require the same nutrients that horses do, just in different amounts. This also means that, similar to horses, donkeys do require additional nutritional support in addition to their forage. While forage, even lower quality forage, will feed a donkey many of its requirements, there will still be nutrient gaps left in their diet. This means, just like horses, donkeys should be given a daily feed or ration balancer to fill these gaps.

When it comes to choosing a feed for your donkey, only those made for horses are appropriate. Feeds formulated for other species (i.e., goats) would not be suitable. Because donkeys are seen as “easy keepers,” ration balancers are ideal because they help fortify their diet with amino acids, vitamins and minerals that are likely lacking in their forage. Ration balancers do not add any unneeded calories to the diet, either. Excess calorie intake can lead to obesity, laminitis or other metabolic diseases.

In addition to meeting a donkey’s nutritional needs, many quality feeds are fortified with pre- and probiotics and other supplements that are just as beneficial to donkeys as they are to horses.

Should I Manage My Donkey’s Nutrition Differently Than A Horse?

Finally, when it comes to feeding management, donkeys are equids and their digestive physiology is still quite similar to a horse. They, too, are hind-gut fermenters and while they may be more efficient in digesting their feed, many of the ways we feed our horses applies to our donkeys. Donkeys should be monitored similarly to a horse. They also should be fed at regular intervals and given free access to clean water.

The major difference in managing the diet of a donkey as compared to most horses is that they are often considered the ultimate easy keeper. Our article on feeding the easy keeper can be reviewed HERE. Briefly, some tips include:

  • Maintain donkeys in an appropriate body condition score (4-6).
  • Feed lower quality grass hays.
  • Feed smaller, more frequent meals (3-4x per day).
  • Encourage more exercise.
  • Use grazing muzzles or limit turn out time to reduce pasture intake.

Take Home Message

To summarize, donkeys are very much like their distant relatives, horses. However, a donkey’s lineage traces back to the arid regions of Africa, so they are much more efficient at utilizing and digesting feedstuffs. Thus, it is highly recommended to feed what we would consider a lower quality “horse” hay at about 1.5% of their body weight per day. In addition to forage, all donkeys need further nutrient support. Generally, most donkeys do well when fed a ration balancer, like Essential K®. In some circumstances, working donkeys needing additional calories in their diets should be supplemented with a low NSC feed. If you have any concerns or questions about what you are feeding your donkey, please contact us for a free, personalized feeding plan.

References

Martin-Rosset, W. (2018). Donkey Nutrition and Feeding: Nutrient Requirements and Recommended Allowances—A Review and Prospect. J. Equine Vet. Sci. 65:75-85.
Mueller, P.J. et al. (1998). Chewing behaviour in the domestic donkey (Equus asinus) fed fibrous forage. Appl. Anim. Behav. Sci. 60:241-51.
National Research Council. (2007). Nutrient requirement of horses, 6th rev. ed. National Academies Press.

Chris Mortensen, Ph.D.