Can Chickens Eat Onions? (Answer Backed By Research)

It’s only natural to wonder if your chickens are safe to eat a certain type of food. We want the best for our flock. And the same holds true when it comes to feeding chickens onions. Fact is, yes, chickens can eat onions. And here’s exactly why I say that, all backed by research.

Is It Ok To Feed Onions To Chickens?

There is a plethora of interesting information in the cyber world about what is safe or not safe to feed your chickens. Onions top the list of the cyber-legends as a vegetable you should never feed your chickens. If you look at the research, rather than the stories, opinions, and tales passed on by great-great-grandparents, the actual facts regarding onions and chickens just may surprise you.

Health Benefits of Chickens Eating Onions

Onions are not only a delicious accompaniment to our meals, but they are loaded with health benefits. Onions are natural blood thinners and make the heart healthier. Quercetin in onions prevents plaque build-up in the arteries and reduces the risk of strokes and heart attacks in humans, but what does an onion do to a chicken?

For chickens and humans alike, onions are anti-inflammatory because of the sulfur quercetin that they contain. It relaxes the airway muscles and helps with breathing. This is a benefit for chickens since they’re known for having sensitive respiratory systems.

The polyphenols in onions are antioxidants that protect against free radicals. This encourages a stronger immune system in poultry and humans. The fiber in onions assists with digestion because of the soluble fiber called oligofructose. It produces good gut bacteria. Chickens are prone to diarrhea, so the oligofructose helps prevent and treat diarrhea.

Research on Chickens and Onions

rooster with flock of hens outside pecking ground

Research was published on the nutritional impact of onions and garlic by the Bulletin of the National Research Center in regards to laying hen performance, egg quality, and impact on blood constituents. The study was conducted specifically on the range of pathogens in the digestive tract, growth rate, digestion, egg quality, immunity and the overall health of poultry fed onions and garlic.

The results showed an improvement in the number of eggs produced by the laying hens fed onion and garlic. There was improvement shown in the general health of the hen, egg weight and quality, better food absorption and a decrease in cholesterol. Onions have vitamins, minerals, and amino and fatty acids that can increase chicken growth.

The Benefits of Chickens Eating Onions Included the Following:

Proven antibacterial
Antiviral
Prevents parasites
Anti-fungal
Antihypertensive
Anti-inflammatory
Promotes antioxidant activity

The International Journal of Poultry Science also published a study on onion and garlic on the effects of poultry used for meat. They concluded that onions improve the efficiency of feed and increases body weight in chickens being raised for meat.

When Can Onions be Harmful to Chickens?

Common sense tells us we wouldn’t sit down and eat an entire bowl of raw onions. Chances are, your stomach would hurt, you would have heartburn, probably followed by diarrhea. So why does feeding onions get such a bad rap?

The sulfoxides and sulfides in onions can cause anemia in animals called Heinz body anemia. This type of anemia can damage red blood cells in dogs, cats, horses, and monkeys. There are no studies that have found this to be the case with chickens.

The green stems from onions are stringy and can be a choking hazard. You probably won’t see chickens eating the green onion shoots found in nature. Even if you threw them into the coop, they would probably not be eaten.

Fried onion rings are not good for chickens. Chickens can’t digest the lipids from fatty foods and fed in large quantities, fried food may impact egg production or egg quality.

A large quantity of raw onions could cause digestive issues with your chickens. Like all snacks used to supplement a flock’s diet, onions should be fed in moderation and never compose more than 5% of their daily food intake.

How to Safely Feed Your Chickens Onions

chicken standing on waterer — Chicken Farm Hens Hen Laying Hens Poultry

We know that feeding a moderate amount of onions to your chickens can act as an antioxidant, improve blood sugar levels and improve bone health. Onions are composed of 89% water, 8% carbs, and 2% fiber. The fiber contains fructans which are great for gut bacteria and makes great fuel to help chickens digest their food. Onions can boost your flock’s immune system and help keep away parasites.

Here’s how to safely incorporate onions into your chickens’ diet.

Cooked onions. Cook onions in a little water until they are soft. Cool them, chop them into small pieces and mix them into feed or with other treats.
Roasted onions on a string. Entertain your chickens with this tasty and nutritious snack. Roast the onions on the grill or in the oven until soft but not too mushy. Pull a string through the onion and suspend them in the coop. The girls will have fun while improving their heart health.
Raw onions. If you have excess onions or onions that are on the verge of going bad (never feed them moldy onions), you can chop them into small pieces and toss them into the coop or mix them into their food. Keep the amount of onion per chicken to about a tablespoon. This is enough to allow them to benefit from the good properties found in onions without causing digestive upset.

Final Thoughts

Onions should be considered one of the vegetables that can be added to your chickens’ diets. They can have numerous health benefits that can’t be obtained through the processed feed. Probiotics are an important part of gut health for chickens and adding onions is an easy way to add that important element to their diet.