The key to feeding donkeys is providing them with just the right amount of food, since obesity is a major issue for these longears. That correct amount depends on the donkeys' size, age and whether they are working animals or just pets.
Donkeys are the most efficient of all equines when it comes to using dietary protein. That means they don't need the higher quality hay horses must be fed. Donkeys developed in desert and other arid climates, basically scrounging around for available forage. That enables the descendants of these desert dwellers to more easily digest what they are fed. Donkeys range from small to quite large, but you should never need to feed a donkey the same amount of food as a horse or pony of similar size. Donkeys should consume between 1.75 to 2.25 percent of their body weight daily. For a 250-pound donkey, that's approximately 5 pounds of forage.
Hay and Pasture
Most donkeys will do well on a plain diet of timothy or grass hay, with access to clean water and a salt block. The American Donkey and Mule Society warns against feeding donkey rich hays, such as alfalfa. While pasture can supply all of your donkey's needs in warm weather, keep him off lush grass. If your pasture is especially green and verdant, either limit the amount of time your donkey spends grazing or put a muzzle on him for part of the day.
Hard-working donkeys or pregnant jennies may require small amounts of grain. Choose a low carbohydrate grain appropriate for donkeys and never give a donkey feed containing more than 12 percent protein.
If an aged donkey -- the species often lives 40 to 50 years -- has trouble chewing hay because of tooth issues, substitute soaked timothy or grass hay cubes or pellets. Make sure the product you choose contains only timothy and grass, and isn't an alfalfa mix. Ask your vet about feeding an equine senior concentrate to your old donkey, and the appropriate amounts for your animal.
Dangers of Overfeeding
Besides obesity -- which comes with its own set of health risks -- overfeeding donkeys can lead to potentially fatal conditions. These include founder or laminitis, which can cripple the donkey for life if he survives the initial bout. Donkeys are prone to various metabolic diseases, including insulin resistance. If your donkey begins sprouting fat rolls, typically on the neck and hips, consult your vet for advice on your animal's diet.