Pigs are renowned for eating just about anything. But despite this impression, and that pigs are omnivorous, they cannot eat truly anything.
In fact, some foods that seem quite wholesome can be bad for pigs and other animals. One of the most contentious is the humble onion.
Depending on who you ask, it is either a good nutritional supplement or outright toxic, and will taint the meat of pigs. What’s the real story? Can pigs safely eat onions?
Yes, pigs can safely eat onions in limited quantities. Though reasonably nutritious, onions have a propensity to give pigs bad gas, and eating too many might impair blood clotting. This can also impart a bad taste to the pig’s meat.
As it turns out, both camps are half correct. Onions are not lethally toxic to pigs no there is the possibility of harm if they eat too many.
Pigs can derive nutrition from onions but the downside is that regular ingestion will give their meat a funky taste. This is a nuanced subject if you couldn’t tell already, so keep reading to get the full story.
What Happens if Pigs Eat Onions?
Onions are not overtly poisonous to pigs and they will not kill them if ingested. However, eating too many onions can cause some health problems for pigs.
The main issue is that onions contain a compound called thiosulfate, which can be toxic in large quantities.
Thiosulfate is found in other foods as well but onions have a particularly high concentration. When thiosulfate breaks down, it releases sulfur which is what gives onions their characteristic smell. This same sulfur can also lead to gastrointestinal distress in pigs.
Pigs that eat too many onions might experience bloating, gas, and diarrhea. In severe cases, thiosulfate poisoning can cause anemia and impair blood clotting.
While thiosulfate poisoning is not necessarily fatal, it can still lead to significant health problems in pigs. For this reason, it is best to avoid feeding onions to pigs in large quantities or too often.
Are Onions Good For Pigs?
Onions can be good for pigs when fed to them in limited quantities. They have vitamins and minerals that pigs need, and also have a stabilizing effect on lipids.
Nutritional Benefits of Onions for Pigs
Onions are reasonably nutritious for pigs and contain a decent cross-section of vitamins and minerals that can benefit them.
Onions are particularly rich in vitamin B6, vitamin C, folate manganese, and dietary fiber. They also contain smaller amounts of calcium, iron, and potassium.
Vitamin B6 is used in the body to make hemoglobin, which carries oxygen in the blood. It is also needed for proper immune system function and for making neurotransmitters like serotonin and dopamine.
Vitamin C is a powerful antioxidant that can help protect cells from damage, and is also involved in collagen production and wound healing.
Folate is important for cell growth, DNA synthesis, and nervous system function.
Manganese is a mineral needed for bone development, wound healing, and proper metabolism of carbohydrates and lipids. All around a pretty solid nutritional profile!
In addition to being a good source of essential nutrients, onions can also help to regulate lipids in pigs.
One study found that feeding onions to pigs helped to reduce total cholesterol levels and increase HDL (good) cholesterol levels. This helps to reduce the risk of heart disease in pigs.
Can Pigs Eat Raw Onions?
Yes, and this is a pretty good way to feed it to them. Raw onions will contain the maximum amount of nutrition but are also a little harder on a pig’s stomach.
Again, so long as you feed them in moderation you should not have any major issues.
Can Pigs Eat Onion Peels?
Yes. Pigs can and will eat all parts of an onion, including the papery skin and the tougher outer layer of the flesh proper.
Can Pigs Eat Cooked Onions?
Yes, and cooking onions for your pigs is advised in some cases. Cooking onions reduces the concentration of thiosulfate, making them safer for pigs to eat.
This is especially important if you are feeding onions to young pigs or pigs that are pregnant or nursing.
Cooking onions also makes them easier to digest, which can be helpful if your pig is already having gastrointestinal issues from eating too many raw onions.
Don’t Give Your Pigs Onions if it Was Made with Bad Ingredients
Since we are on the subject of cooking, now is a good time to remind you that you must never feed your pigs onions that have been prepared with harmful ingredients. Things like salt, sugar, or onions that have been cooked in grease are all off-limits.
At best, these ingredients will cause even more digestive issues for your pigs.
At worst, they could be seriously harmful, doing damage to liver, kidneys or intestines, and even potentially fatal.
So, only ever feed your pigs onions that are cooked plain or with other healthy ingredients.
Be Mindful of Pesticide if the Onions Came from the Grocery
It is a sad fact that pretty much all commercial produce is heavily treated with pesticides, among other chemicals. Intended to keep veggies in good shape until they can reach market, they have been linked with serious harm in mammals, including pigs.
Pesticides have a way of building up in body tissues over time and eventually resulting in catastrophic health issues like cancer, organ damage, and reproductive problems.
So, if you are going to feed your pigs onions from the grocery store, be sure to wash them thoroughly first.
Ideally, you should try to get your hands on organic onions that have not been treated with any harmful chemicals. This way you can be sure that your pigs are getting the healthiest possible onions to eat.
Can Pigs Eat Onions Every Day?
Pigs should not eat onions every day, generally. Though a few bites a day won’t hurt, regular ingestion of larger quantities can cause gastrointestinal distress and may even lead to anemia from the loss of red blood cells.
How Many Onions Can Pigs Have?
As a rule of thumb, you should only feed your pigs a small serving of onion once or twice a week if you want to prevent issues, including the tainting of meat. This way they can get the benefits of onions without suffering any ill effects.
Also bear in mind that the amount of onions pigs can have with no concerns is proportional to their weight! Smaller pigs will, of course, be able to handle less onion than their larger counterparts.
How to Give Onions to Your Pigs
The best way to give your pigs onions is to chop them up into quarters or small pieces or slice them thinly. This will make it easier for them to eat without a major risk of choking.
You can also cook onions before feeding them to your pigs, as this will make them easier to digest and reduce the risk of problems. When cooking just follow the same guidelines: quarters, small pieces, or thin slices.
Also consider mixing onions in with other foods, vegetables or otherwise, to make an interesting and well-rounded meal for your herd.
Can Baby Pigs Have Onions, Too?
Yes, but only tentatively. It is best to wait until baby pigs are properly nearing adolescence before introducing onions into their diets.
This will give their digestive systems time to develop properly and allow them to better handle the sulfur compounds in onions.
You should also start with very small quantities of onion, gradually increasing the amount over time as they get bigger and their systems can handle it better.
Piglets are far more sensitive to the harmful side effects of onions than adult pigs, so you should also sharply limit the quantity.
Frequently Asked Questions
Yes, pregnant sows can eat onions so long as you follow the guidelines above. A pregnant sow will not be immune to the potentially harmful effects of onions while pregnant, but they will not otherwise harm her piglets in utero.
Not really. Onions lack the calories that pigs need to put on weight in a hurry. They do, however, fit into a properly balanced diet as they are a good source of nutrition.
Yes, pigs can eat green onions, though they might be put off by the taste.
Tom has built and remodeled homes, generated his own electricity, grown his own food and more, all in quest of remaining as independent of society as possible. Now he shares his experiences and hard-earned lessons with readers around the country.