ISA Brown Chicken Egg Color, Size, and Laying Numbers

The ISA Brown chicken egg color is brown. It’s often described as chestnut or tan brown and is a darker shade than other brown-laying breeds like Rhode Island Reds and Buff Orpingtons.

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What Color Eggs Do ISA Browns Lay?

ISA Browns lay brown eggs. The shade will vary, as it does with all breeds of chicken. Generally speaking, however, they lay a medium to dark brown color egg.

ISAs make up the largest population of the world’s brown egg-producing chickens. So, whether you’re aware of it or not, I’m sure you’ve seen their eggs.

Just take a look at the eggs for sale in your supermarket next time you’re there. They often don’t say on the carton which breed or type of chicken laid them, but they might.

Either way, if they’re a rich brown color, it was likely laid by an ISA Brown. Or a Rhode Island Red which is also a popular breed used for commercial eggs, although their eggs tend to be a lighter brown.

How Long Before ISA Brown Chickens Lay Eggs?

If you’re buying ISA Brown chickens I’m sure you’ll be well aware that they are one of the most prolific laying hybrids.

They also come into maturity sooner than a typical breed. ISA Browns will typically start laying eggs around the 18-22 week mark. That’s about four and a half months old.

Just like any other chicken, they will start out laying ‘pullet eggs’. These are smaller in size, and often a slightly odd shape. This usually happens for a month or so while the chicken is reaching full maturity.

Once they are laying at peak production, ISA Browns lay large eggs with an average weight of around 63 grams.

How Many Eggs Do ISA Browns Lay?

ISA Brown chickens are not referred to as ‘Global superstar layers’ for no reason. They are one of the most prolific laying breeds. For this reason, they are more popular in commercial settings than backyards, as obviously they make egg farmers good profits.

I’ve read accounts that they can lay in the range of 300-330 eggs in their first full year. This is with all the ideal environmental conditions made available. This number then drops off sharply over the next two years.

According to ISA-Poultry.com who sells ISA Brown and ISA White chickens, they say you can expect 460-500 eggs from an ISA Brown over their lifespan. Which is only around 100 days in a commercial setting.

Now, I’m not a fan of egg farms, caged chickens, battery hens, and any of those methods of mass-producing eggs (for obvious reasons). But, for the record, that is how many eggs ISA Brown chickens are expected to lay under those conditions.

In a homestead or backyard setting, although still one of the best layers, you will have fewer eggs. The good news, however, is that they are expected to live longer when cared for as beloved backyard pets.

I’ve read accounts of ISA Browns living as long as 5 years when kept in an urban setting and allowed to roam free-range. That’s quite the difference from the two years they are given as commercial objects kept to lay as many eggs as possible.

Related - How long do ISA Brown chickens live for?

How Big Are ISA Brown Eggs?

The average weight of an ISA Brown egg is 63.1 grams (2.22 oz.). That means according to US industry egg sizes they lay large eggs.

An extra 0.7 grams on average and they would be classified as very-large or extra-large layers. So, don’t be surprised if your ISA lays very large eggs.

In case you’re not familiar with the weights and sizes of eggs (why would you be?), here is a table:

US Standards and Classifications of Egg Sizes

Name	Approx Weight
Peewee	1.25 oz*
Small	1.50 oz*
Medium	1.75 oz*
Large	2 oz*
Extra Large	2.25 oz*
Jumbo	2.5 oz*

What Does an ISA Brown Chicken Look Like?

The short answer to this is that ISA Brows looks like stereotypical brown chickens, right?

They don’t have any unique or standout features as such. The hens are medium-sized birds, with a nice chestnut brown plumage. They tend to have white tail feathers and some white feathers on their sides, and a single red comb and a small wattle.

ISA Brown roosters look very different. Their plumage is mostly white, with brown patches and larger combs and wattles.

How Do You Pronounce ISA Brown Chickens

ISA stands for ‘Institut de Sélection Animale’, the company that first created the ISA Brown. So, as you would do with any acronym, you pronounce ‘ISA’ by spelling out the letters.

Meaning it’s said as ‘I S A Brown’.

Simple, right? I’m glad they shortened it, I couldn’t imagine saying Institut de Sélection Animale more than once a day!

In Summary

If you’re interested in adding ISA Brown chickens to your backyard flock, you can’t really go wrong. They have a lovely temperament, are happy foraging around, and of course, they lay lots of large brown eggs.