Chickens seem to be the veritable garbage disposals of the farming world. Like pigs, it seems there isn’t much in the way of food that they won’t pick at or even consume entirely. Even so, as responsible chicken owners, it is natural to want to make sure that we are offering them foods that are safe to eat.
Can chickens eat onions? All of the parts of the onion are safe for chickens to eat in limited quantities. This includes the onion itself (also called the bulb), the stalk, and the flowers.
What That Means
Onions have been scientifically proven to be toxic for many animals including dogs, cattle, sheep, and geese. But each species reacts to foods in a different way.
Humans can eat onions without issue and, even though they are toxic to some animals, eating small amounts doesn’t typically cause an issue.
The problem with answering this question specifically lies in the fact that I was unable to find any scientific research that indicates onions are either toxic or safe for chickens.
I was able to find several scientific studies that illustrate that onion and onion extract are often purposefully fed to chickens.
That, along with my personal experience, leads me to believe that onions are safe to feed to adult chickens, in limited quantities.
Additionally, you shouldn’t force your chickens to eat onion. I would not recommend mixing it with their regular food or providing it as the only or major ingredient in their diet. Giving the option to pick at it if they want is probably fine.
Scientific Studies on Feeding Onions to Poultry
Feeding Onion to Chickens Can Make Their Eggs Taste Oniony – In a 2001 study, researchers found that feeding chickens a diet of laying meal plus cabbage and onions caused their egg yolk to emit an “onion-like” odor.
Chickens Are Sometimes Purposefully Allowed to Forage on Onion Crops – A 2017 study looks at the manure of chickens feeding on a variety of crops, including onion, and how that affects the ability for their manure to germinate seeds. While the study might be interesting for those of you using your chicken manure as fertilizer, it also shows us that sometimes chickens are purposefully allowed to forage on onion crops.
Onion Extract Can Help Chickens Gain Weight – In 2017 a study was published in the Asian-Australas Journal of Animal Science that covered the effects of feeding broiler chicks onion extract. Researchers found that feeding onion extract improved weight gain and meat quality.
Onions Can Be Fatal to Geese – In a 2004 study conducted by the California Animal Health and Food Safety Laboratory at UC Davis, researchers found that feeding green onions to geese caused anemia and negatively affected liver functionality.
How Much Is Too Much Onion to Feed to a Chicken?
Unfortunately, I couldn’t find an answer to this question. Again, due to the fact that I wasn’t able to find scientific literature supporting that they are toxic (or safe).
In my flock, I only feed small amounts of onion comparatively. I won’t feed a whole onion but I will feed the pieces of onion I cut off when I slice the vegetable, as well as any leftover onion greens.
As far as cooked onion, typically my chickens get a cooked onion when I am feeding them a leftover that has onion as an ingredient.
It makes sense to try to limit feeding any onion to adult birds only. Young chicks are more likely to be susceptible to adverse effects from any treat, so introducing onion into their diet should probably be avoided.
Onion Nutrition Facts
- Onions are about 84% water
- Onions contain 1.8 grams of protein
- Onions contain ~40mg of Calcium
- Onions contain ~60 mg of Phosphorus
- Onions are antimicrobial
Onions are toxic to many animals, including Geese. For chickens though, they seem to be safe when fed in limited quantities. Care should be taken to ensure they are only fed to adult chickens and in moderation.