ISA Brown Chickens – Breed Profile & Facts

If you are looking for prolific egg layers, then ISA Brown chickens are the best choice for you. ISA Brown chickens are the most sought-after birds in the poultry industry. They are even a preferred choice of chickens for a backyard flock. Their friendly nature makes them bond easily with their keepers.

Most importantly, they are a rich source of protein thanks to their delicious meat and big, brown eggs. Speaking of eggs, a single ISA Brown hen can provide your family with about 300-350 eggs per year. That’s why this type of chicken is highly prized by most chicken keepers. Overall, ISA Brown chickens are suitable for your small rural barnyard or urban yard.

ISA Brown Chickens History

The acronym ISA is derived from France’s Institut de Selection Animale. This is the place where ISA Brown hybrid chicken was developed more than four decades ago. To date, this prolific layer has remained the undisputed top global brown egg layer.

Quite a number of backyard chicken keepers include one or two (or even more) ISA Brown chickens to their flock. Sadly, not everyone can get pure ISA Brown roaming their backyards. This is because the ISA brown chicken breeding formula is a guarded secret.

However, a close look at chicken breeds such as Rhode Island Reds, Rhode Island Whites, and White Leghorns can give you an idea about the genetic makeup of the ISA Brown hybrid.

Certainly, ISA brown chicken breed is highly regarded as a copyrighted or a proprietary chicken. What this means is that no other person except ISA (the creator) has full knowledge of the exact genetic makeup of this hybrid. Also, it means no one else should use or adopt the name ISA Brown for their breed or line of birds.

During the breeding and experimentation, ISA Brown was engineered primarily to produce eggs prolifically for a considerable length of time. The general public can acquire ISA Brown chickens fairly inexpensively.

Characteristics of ISA Brown Chickens

When it comes to appearance, ISA Brown chickens are not such a unique breed to identify. ISA Brown chickens look much like most brown breeds of chickens. If you are not careful enough you can mistake them for Rhode Island Reds, Comets, or Red Star Chickens.

With these birds, you can easily identify hens from roosters. They are sex-linked whereby a few days after hatching their fluff color helps you determine an individual chick’s sex (male or female).

Hens display vibrant fluff balls complete with light brown color and a few white speckles. As they grow older, their white feathers become noticeable while the brown color changes to chestnut or deep red. In addition, female ISA Brown chickens develop white feathers upon maturity.

On the other hand, male ISA Brown birds display the reverse color of feathers of their female counterparts. Their feathers change to white with numerous brown speckles. Physically they get bigger than hens. Combs and wattles stand out more than what you will see in hens. Tail feathers become white in color but bigger than those in ISA Brown hens.

Regardless of their sex, ISA Brown birds have characteristic small, single combs with yellow feet. Both have distinctive white tail feathers. Below are additional features to make you understand ISA Brown chickens better:

– Size & Weight

ISA Brown chicken weighs between 2 and 3 kg (4.4lbs and 6.6lbs). The average market weight for a medium-sized pullet is usually 1.6kg(3.5lbs) while the medium-sized cockerel has an average market weight of 1.8kg (4lbs).

The average size/weight of an egg laid by ISA Brown hens is 63.1grams (0.14lbs). From this average egg size, you can tell that ISA Brown hens lay large eggs, which are slightly less than the extra-large eggs as per the US industry egg size requirements. Well-kept ISA Browns are likely to lay extra-large eggs as well.

Since they are considered globally as the most prolific layers, ISA Brown hens have exceptional feed conversion ability. From a commercial egg farming point of view, feed conversion means they are profitable when compared to the cost of feeding them. The aforementioned egg size is only for commercially raised hens.

– Temperament

Besides their popularity, ISA Brown chickens are calm and gentle birds. They can provide great company to your children. ISA Brown chickens are also docile, meaning that they can make good family pets. These two characteristics make them popular among homes with children, small farms, and backyard chicken coops.

Even though they have a cool temperament, ISA Brown chickens are very social with different people. You can enjoy cuddling them in your lap or spend your free time with them in the backyard.

– Lifespan

Sadly, ISA Brown chickens have a significantly lower life expectancy than most healthy pure-breed birds. Their short life expectancy is indirectly related to their egg production, which is usually higher than for most layers.

ISA Brown chickens are bred to keep on laying eggs throughout the year including the wintertime. This should tell you that their reproductive system is not getting a rest. Sheer exhausting can possibly cause early death.

That said, most ISA Brown chickens live from 2 to 3 years. Reports indicate that some ISA Browns have live to about 5 to 8 years, which is a lifespan for all other chickens. Their lifespan depends largely on the type of care they are given. So, make sure you look after your ISA Brown chickens well, give them the love they need, and feed them healthy chicken feeds to have them around for some years.

– Egg Production

It’s never easy to tell when your hens are going to lay their first eggs. Regardless, you should expect your ISA Brown layers to start laying eggs as soon as possible given that they typically mature faster than most chicken breeds. Some chicken owners claim that they have seen their ISA Brown hens start to lay their first eggs at around 4 to 5 months (16 to 18 weeks).

As a prolific egg-producing chicken breed, your ISA Brown is likely to lay an average of four eggs per week. In one year your ISA Brown hen will lay more than 300 brown eggs. By two years of laying eggs, the production may slow down significantly.

– Meat Production

ISA Brown chickens don’t make excellent meat producers. This is because they are bred to produce eggs. Once your ISA Brown layer gets old, you can slaughter it for your family to enjoy the meat.

ISA Brown Chickens Care

Before you start keeping ISA Brown chickens, you need to know how to care for them. In this sense, you should provide the following:

– Feeding & Nutrition

For your ISA Brown chickens to be productive, you need to provide them with a proper diet. Make sure they get sufficient amounts of chicken feed to make them grow and maintain their egg production power.

Calcium and protein-rich foods should be in plenty because these are prolific egg-laying birds. These essential nutrients play a significant role in helping your birds stay healthy as well as produce quality eggs.

– Housing

Your ISA Browns will take confinement well although they prefer open places. Even though they wander off too far, they will still stay close to their coop. This is the reason you should keep your ISA Brown chickens within a free-range system. This way, they will acquire free proteins from tasty bugs and worms in addition to grazing on some fresh herbs.

Comfy and quiet nesting boxes will be fine for egg layers. Add some soft bedding to their boxes to keep them warm and comfortable. Perching space is also necessary as it will keep your birds safe from predators. Don’t forget to keep their coop clean and dry all the time.

– Health Problems

Just like other domestic animals, ISA Brown chickens are likely to suffer from a number of health problems. Most of these problems arise as a result of their purpose. These birds are bred to lay more eggs within a short time and this has created a negative impact on their well-being.

Layers tend to fall ill or develop some health problems after one or two years of their age.

The most common types of ailments that affect ISA Brown chickens are those associated with their reproduction system. The system is usually overworked to produce as many eggs as possible in a short time. Examples of these health problems include tumors, cancers, and prolapse. In some cases, they may suffer from kidney conditions.

ISA Brown Chickens Breeding

ISA Brown chickens pose some challenges to those looking to breed them. Their hybrid nature does not allow them to breed true and their offspring are usually weaker than them. Apart from that, their offspring are at a high risk of developing kidney diseases.

Therefore, you should not breed your ISA Brown chickens on your own unless you are a professional. Look for a knowledgeable and experienced breeder to assist you.


ISA Brown chickens are quite productive in terms of eggs. These chickens are a great option for backyard chicken keepers and small families.

Their friendly and cool nature makes them a perfect choice for family pets. With good care, ISA Brown birds can be a great investment and a reliable source of proteins for your family.

avatar James
Hey, I'm James, a hardworking homesteader for more than 30 years. I enjoy the feeling of accomplishment that comes from tending my flock. I've raised chickens and ducks for eggs and meat for many years. I also have experience with other poultry too. Learn more

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