Let's start at the beginning: what, exactly, is garlic?
A member of the onion ('Allium') family, garlic is classed as a vegetable although many people think of it as a herb.
It consists of a number of small 'cloves' bunched together into a 'bulb' or 'head' and covered with a thin, paper-like coating.
Originating in Asia, it's been around for centuries and has been used medicinally for human beings for almost as long.
Here in Italy, which has one of the lowest rates of heart disease and cancer, it's used freely and in fairly large quantities in human recipes.
But what about garlic for chickens? Does it really have the benefits that some people claim?
Take a look at this quote from a Veterinary study talking about garlic as a supplement in the poultry diet:
"Garlic is the king of the medicinal plants... It has antibacterial, antiviral, antifungal and antiprotozoal properties. Moreover, it boosts the immune system, improves body weight gain, heightens the digestibility of ingredients, decreases bad cholesterol, and also augments the meat quality parameters." (2).
This is a very long article, covering all aspects of the health benefits of garlic for chickens. If there's specific information you're looking for, these links will help.
Absolutely. Chicken keepers have used raw garlic for years to help ward off a whole list of poultry ailments including respiratory problems, infection, and as a general support to the immune system.
You may see articles saying that, because it's part of the onion family, garlic is poisonous to chickens. Not so.
The make-up of garlic is entirely different and the element that causes issues in onions - thiosulphate - is present only in tiny quantities in garlic.
Dozens of scientific, peer-reviewed trials have shown beyond doubt that garlic is beneficial to chickens' health and wellbeing.
It promotes growth in weak chickens (and broilers, but we won't go there), and even has a positive effect on the nutritional value of eggs.
We'll look at specific uses below.
There's always a but...
Any addition to your chickens' daily feed should only be given if there is evidenced research about the benefits.
With garlic, that certainly exists - it's one of the most highly researched plants available. See the sources section below - and there's a lot more where that came from!
But it's important you don't go overboard with this. As always, it's moderation in everything. Too much garlic will interfere with the balance of bacteria in the digestive system.
Test it in small quantities, adding gradually to food or drink. Don't try to put an entire garlic bulb in your chickens' water if they've never had it before - they simply won't touch it.
Again, in moderation.
It will help build their immune system and helps guard against worms. And chicks who have tasted garlic water soon after hatch are more likely to accept it as adults.
Gail Damerow suggests giving a small amount, no more than one clove (not a bulb!) to one litre (1.5 UK pints; 4 US cups; one quart) of water. Crush the garlic into the water no more often than twice a week.
Don't allow the garlic water to stand for longer than 48 hours. In between times, offer ordinary water as usual. And keep an eye on the chicks - if they're not drinking, they will easily dehydrate.
In that case, revert to water without the garlic. Try again in a couple of days. Reduce the amount of garlic at first, gradually increasing it over time.
Garlic is touted round the internet as a cure for everything from cancer to the common cold. But there's lots of misinformation out there, too.
So what exactly is the evidence of garlic's benefits for chickens?
Here are some instances where garlic has been proven to have a beneficial effect on poultry.
You'll find a lot of articles online saying that garlic kills worms in the gut. The fact is there's not much research on this and it should not be used in cases where worms have already taken up residence.
There is some research in mice that worms in the gut were reduced in the first week after being fed garlic. After that, it had no effect.
The scientists concluded that the garlic was not killing the worms directly, but building up the immune system to fight the inflammation the worms brought.
If you see worms in your chicken poop, it's too late for garlic - you need a proven wormer such as Verm-X. (This is an "affiliate link", which means that if you click and buy, I earn a small commission at no extra cost to you).
That said, adding garlic to the diet is known to make the environment less attractive to red mite and it may have a similar deterrent effect on worms.
But, as above, do not expect it to kill worms already colonised in the gut. Take immediate action if you see worms. Add garlic to the flock's diet once you've got rid of them.
Remember: the word is "moderation".
You'll see different recommendations around the Internet, but the way to go is to follow advice from experts and findings from real studies. Which is how I came to this advice:
When a garlic clove is crushed, it releases an element called 'allicin'. Allicin is known to be a forceful anti-oxidant, which works either by itself or with other compounds to strengthen the immune system. In chickens it's therefore effective against various bacteria and viruses.
However, the strongest benefits of crushed garlic seem to weaken after 24 hours. So if adding to food or drinking water, be sure to refresh after, at most, 48 hours.
Crush using either a pestle and mortar or save the hassle of peeling by using a garlic presser like this one. (Affiliate link).
This is probably the easiest way to make sure your flock get their dose of raw garlic. Simply crush 1 clove per litre (4 per gallon) into their drinking water or, if you're using it, add to their electrolyte drink.
Garlic in water tends to lose its effectiveness quickly. In oil, it's preserved for longer. So you'll see some advice about drizzling garlic-infused oil on your flock's feed.
However, there's evidence of an increased risk of botulisms produced by garlic soaked in any oil unless either the cloves are cooked, or the garlic-infused oil is refrigerated in the short term or frozen in the longer term.
There's lively debate about this in chicken (and human wellness) forums. You'll find some advice which says always give fresh, not processed, garlic. That's certainly what I like to do whenever I can.
But statements saying that heat processing to make garlic powder reduces the effectiveness seem unfounded, if scientific research is to be believed.
Studies, such as this one published in the International Journal of Poultry Science, have demonstrated that adding no more than 1% of garlic powder to a hen's diet increased both the rate at which hens laid, and the quality, including weight, of their eggs.
Want to keep some powdered garlic on hand? Dry it yourself by slicing your cloves thinly and baking at a very low heat for about 2 hours. Store in a glass jar and, when you're ready to use it, simply grind it with a pestle and mortar.
Alternatively, use a dehydrator. It will keep in a sealed jar for about 6 months.
Or, buy a stock of garlic granules. Avoid the fried variety and go for organic, non-GMO. I use these at times when I don't have any fresh garlic, or don't have time to crush or powder it.
Once opened, store in an airtight container. Sprinkle on feed twice a week, or add to water at the rate of 1% of the feed weight.
I use around one teaspoon per kilo.
It's commonly thought that adding garlic to your hens' diet will make their eggs taste and smell of garlic. There's no doubt that if you add a lot of garlic to the diet, eggs will taste differently.
But "a lot" means at least 3% of your flock's daily feed - 30 grammes per kilo (1oz per 2 lbs). That's a lot of cloves, and it's highly unlikely you'll ever feed anything like that amount.
A study by Clemson University as far back as 1988 found that testers actually preferred the taste of eggs from the hens fed on garlic. They found the eggs tasted milder, probably because garlic is known to reduce the sulphur content.
There's hard evidence from scientific studies that, with an addition of just 1.0% of garlic to hens' feed:
The Clemson University study found that adding garlic to feed reduced the ammonia smell of poop in the coop: "It makes the poultry house smell like a pizzeria instead of manure".
So if you want your coop to smell like a pizzeria, you know what to do!
Given that garlic has such amazing benefits for chickens, it makes sense to give them the best you can find.
Growing your own ensures that it's fresh, not genetically modified and free from chemical treatments.
And it's really, really easy to grow the most delicious bulbs, even if you have limited space.
Follow this link to discover how easy it really is to grow organic, untreated, delicious, healthy garlic for your flock - and for your family!
A lot of "facts" you'll find on the internet are often people's individual views, often based on inaccurate information repeated from poor quality sources.
The information I provide in this article and others is based not just on my own experience, but on evidenced facts from scientific, peer-reviewed research and from highly respected and experienced poultry keepers such as Gail Dammerow.
Some of the sources I have used are these - click the link to read the full document:
1. Damerow, Gail: The Chicken Health Handbook. Pub. Storey, 2015.
2. Rehman, Z., and Munir, M: Effect of garlic on the health and performance of broilers. Pub. Veterinaria, 2015.
3. Olobatoke, R., and Mulugeta, S.: Effect of dietary garlic powder on layer performance, fecal bacterial load and egg quality. Pub. Poultry Science, 2011.
4. Khan, S. et al: Effects of dietary garlic on performance and serum and egg yolk cholesterol in laying hens. Pub. Asian Journal of Poultry Science, 2007.
5. Abdulaziz, A: Effects of different dietary levels of garlic (Allium Sativum) powder on productive performance and egg quality of laying hens. Pub. International Journal of Poultry Science, 2016.
6. Bruso, J: Which is healthier: raw or cooked garlic? Pub. Livestrong, 2017.