Isa Brown Chicken Breed Guide: Size, Variety, Eggs, Care & Pictures

Isa Brown chicken is a beautiful egg-laying hybrid bird. Many farmers love to grow chickens, either for meat or eggs. So, we can say it is a dual-purpose chicken.

Farmers raise this chicken, especially for the bulk needed for egg production. The massive egg-laying capacity makes this fowl among the top-most egg-laying birds.

Also, Isa Brown’s chickens are very sweet and quiet-mannered. These breeds love to spend time with human families. The beautiful hens of this breed are very attractive.

This article details the Isa Brown chicken’s history, temperament, egg production, behavior, characteristics, color, size, problems, benefits, and raising tips.

What is Isa Brown Chicken?

Isa brown chicken foraging in green garden
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The French company ISA selectively breeds Isa Brown chickens, prized for their egg-laying and friendliness.

These hens weigh 5–6 pounds, and roosters 6–7 pounds, and they have reddish-brown plumage. Chicken lovers love this breed for its brown coloration and placid disposition, making them ideal backyard commercial use flock.

They are famous for their egg-laying ability. The hens are raised for their large size brown eggs. They lay around 300+ eggs yearly, making them a good choice for individuals who want a steady supply of fresh eggs.

Isa Brown chickens need proper care and management to maximize their welfare and production. Scratching, dust bathing, and foraging are natural for Isa Browns in free-range or well-spaced cages. The health of Isa Brown’s hens depends on temperature.

History and Origin of Isa Brown Chickens

ISA, a French company, began selective breeding Isa Brown hens in the 1970s to create a high-performing hybrid layer.

The goal was to develop a chicken breed with high egg production and other beneficial characteristics. This breeding program produced the Isa Brown chicken, a hybrid with global popularity.

Also, the company bred Rhode Island Red and White Leghorn chickens in the early 1970s. These parent breeds were chosen for their health, flexibility, and egg-laying ability.

The breeding program included the most excellent qualities from both parent breeds to generate a hybrid that exceeded commercial egg production criteria.

By the mid-1970s, ISA’s efforts paid off. The Isa Brown set egg output records with its productivity and efficiency. It stood out to small-scale poultry caretakers and huge commercial egg producers because it consistently laid huge brown eggs.

A global reputation for reliability and productivity helped Isa Brown succeed in the 1980s and 1990s. It was popular because it laid eggs and was gentle, making it easy to handle.

The Isa Brown birds are used in poultry farms worldwide, boosting egg production. Strategic breeding programs that improved the qualities of the poultry industry have proven successful in the breed’s history.

Isa Browns remains a popular choice for dependable, productive layers with a proven breeding and performance history.

The Lifespan of Isa Brown Chickens

Like many other chicken breeds, Isa Brown hens’ lifespans depend on care, genetics, environment, and health. Isa Brown hens live 5–7 years on average.

Chickhood (0-6 weeks): In their first weeks, Isa Brown chicks need careful temperature, feeding, and predator protection. Proper treatment can turn them into pullets.

Pullet Stage (6-20 weeks): Growth and development are crucial throughout this stage. Isa Browns mature swiftly from chicks to sexually mature hens.

Egg-Laying Years (20 weeks onward): Isa Brown hens hatch eggs prolifically from 20 weeks forward. It can last several years, with egg production peaking in the first two to three years.

Productive Years (2–3): Isa Brown hens lay the most eggs in their first few years. They consistently lay several big brown eggs throughout this time.

Decrease Egg Production (3-4 years): A natural drop in egg production occurs as hens age (3-4 years). Although the number may drop, Isa Browns may lay eggs after their peak years.

Senior Years (4-7 years): Isa Browns become seniors after their prime laying years. They may lay fewer eggs and have a decreased lifespan. Proper care becomes increasingly crucial for their health.

Recognized Continental Breeds and Varieties of Isa Brown Chickens

Isa brown chickens inside fencing
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Traditional poultry breed standards do not recognize Isa Brown chickens as unique because they are a hybrid. The French company Institut de Sélection Animale (ISA) crossbred them.

Instead of following a breed standard, Isa Brown chickens are crossbred to emphasize the combination of hybrid strength and parent breed features.

Isa Browns may not have recognized color variants, but the poultry industry values them for their consistent and prolific egg-laying. Their distinctive reddish-brown plumage and hybridity boost their vitality and output.

Isa Brown Hen’s Egg Production

Most Isa Brown hens lay eggs between 20 and 24 weeks. They become sexually mature and have fully formed reproductive systems.

Isa Brown hens are known for their excellent egg-laying. The average healthy Isa Brown hen lays 300–350 brown eggs annually.

Their eggs are larger than those of other chicken breeds, however, individual chickens differ. Egg size is also affected by nutrition and heredity.

Isa Brown hens rarely go broody because of their hybrid gene. This makes them ideal for consistent egg production.

Do you know that lots of chickens lay colored eggs? If not, then read our guide on chickens that lay colored eggs.


Isa Brown chickens are known for their calm and gentle behavior. They are easy to handle and ideal for backyard flocks and human-dominated areas.

These hybrid chickens exhibit social behavior. They usually get along with other flock members, decreasing aggression.

Isa Browns adapt to diverse situations and management types. They adapt well to free-range or limited habitats. Their versatility makes them popular with novice and experienced poultry owners.

The Isa Brown hens and roosters often have low aggression behaviors. This is especially useful in mixed flocks with multiple breeds or hybrids. Their friendliness reduces flock aggression.

These hybrid roosters are generally neither aggressive nor violent, making them a good choice for flocks.

Isa Brown hens have less broodiness than some historical breeds. Individual hens may be broody, but it’s rare.

Size and Weight

Isa Brown chickens come in medium sizes and have a balanced body weight, making them ideal for egg and meat production.

The average adult Isa Brown hen weighs 5 to 6 pounds. This weight range is moderate for laying hens, allowing them to lay many eggs without being overweight.

Isa Brown roosters weigh 6–7 pounds, significantly more than hens. This reasonable weight lets them work in a mixed flock without being too big or aggressive.

Due to their intermediate size, they can thrive in backyard flocks and commercial production systems.


Isa brown chicken drinking water in backyard
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The bodies of Isa Brown hens are balanced and symmetrical. They look beautiful because their bodies are neither too compact nor excessively extended.

Isa Brown hens have homogeneous reddish-brown plumage. Feathers cover the body, wings, and tail. Usually, they have yellow skin under their feathers.

A single, medium-sized comb is characteristic among Isa Browns. Red single-type combs enhance their plumage.

Wattles are medium-sized red that match Isa Brown’s combs and look. 

Isa Brown hens have yellow legs. These hens look uniform due to their leg coloring.

Their reddish-brown plumage and eye color match to give them a unique look.

Hardiness Characteristics of Isa Browns

Isa Brown hens are hardy because they can withstand varying weather conditions, diseases, and management techniques.

They tolerate various climates and can survive in hot or cold weather with proper shelter and care. Proper housing, ventilation, and temperature protection improve their health.

Isa Brown chickens are developed for strong health and resistance to common poultry diseases. Like any breed, immunization, biosecurity, and environmental cleanliness can affect their resistance.

They have good feather coverage, protecting the outdoors. Healthy feathers regulate body temperature, making chickens comfortable in every climate.

Isa Browns are hybrids, which can increase their hardiness due to their general strength and vitality.

They are hybrid chickens with greater vitality and resilience. They are bred for versatility and high egg production to flourish in many environments.

Isa Brown chickens adapt well to various management systems, making them suitable for commercial and backyard poultry farms.

They can be kept in free-range or confined systems, making them versatile and accessible to many poultry owners.

Isa Browns are noted for their low maintenance needs compared to other heritage breeds. Their durability and growing ability with minimum care make them perfect for chicken farming beginners.

Benefits of Raising Isa Brown Chickens

isa brown free-ranging in freezing cold temp
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Isa Brown chickens are profitable for small-scale and commercial poultry farms.

High Egg Production

Due to their excellent egg production, producers choose these hens to increase profit.

Isa Brown lays 300–350 eggs yearly, providing a consistent supply of fresh eggs for consumption or sale.

Gentle and Friendly

Isa Browns are sociable and docile in addition to laying well.

They are easy to handle and ideal for families and people who like to interact with their flock.

Their peaceful nature reduces stress-related health issues, improving flock health and production.

Low Feed Conversion Ratio

Isa Browns efficiently turn feed into eggs due to their low feed conversion ratio.

Farmers who want to cut feed expenditures and increase egg output could benefit.

Even on lower-quality feeds, these hens have a strong feed-to-egg conversion rate, making them a cost-effective solution for limited budgets.

Adaptable to Climates

Climate and environmental adaptation are other traits of Isa Brown.

Farmers in severe temperature locations benefit from their ability to withstand hot and cold weather.

They flourish in free-range or confined spaces because of their toughness.

Additional Income

Finally, selling additional Isa Brown chicks or mature birds can provide income.

Due to their popularity and appealing features, farmers and backyard flock starters typically want them.

Problems in Raising Isa Brown Chickens

Hard to Keep in a Confined

Keeping Isa Brown’s hens in a coop or portable tractor is challenging. They only live in large backyard spaces. You can’t confine these birds for long; their tolerance is low.

The breed’s hens and roosters always stay together, so they need lots of space. No one can keep them in a small space because it will disappoint.

Have Low Disease Immunity

This breed can’t withstand flu, bacterial, or serious infections. Brown cheeks are low and disease-resistant.

Diseases also weaken Isa Brown’s hens and roosters. Proper vaccination must be done to avoid any major disease.

Care Guide For Isa Brown Chickens

Isa Brown hens have numerous benefits, but like any breed, they have drawbacks. There are seven potential issues with raising Isa Brown chickens:

Overcrowding Difficulties

Like other chicken breeds, Isa Browns may encounter stress and health difficulties in overcrowded situations. Overcrowding may increase flock aggression, competition for resources, and disease transmission.

Health Issues

Isa Browns are bred for disease resistance but are still susceptible to health issues. They can have respiratory diseases, parasites, and reproductive issues. Preventing and treating health concerns requires vigilant health monitoring and veterinarian treatment.

Potential for Aggression

Despite their gentle nature, Isa Browns can become violent because of overcrowding, limited supplies, or new birds. It may cause feather pecking or more significant flock injuries. So, keep an eye on these things to avoid aggression and stress.

Egg Laying and Reproduction Issues

Isa Browns may have reproductive difficulties such as egg-laying anomalies or reproductive organ issues despite their egg-laying solid skills. This can harm health and egg production.

Broodiness Management

Isa Browns are less likely to brood than some heritage breeds, although it may still happen occasionally. Broody hens might stop laying, reducing egg production. If broodiness occurs, effective management is needed.

Feather Pecking and Cannibalism

Stress, overpopulation, or dietary deficiencies can lead to these behaviors in flocks. Isa Browns may exhibit these behaviors. Thus, enrichment and space are essential.

Environmental Stressors

Isa Browns are susceptible to unexpected environmental changes, such as temperature variations, poor ventilation, or inclement weather. Maintaining health and productivity requires addressing these pressures.

These issues can be addressed by providing adequate housing, monitoring flock health, giving a balanced feed, and preventing flock stress and hostility. Careful attention to these aspects can reduce Isa Brown chicken raising issues.


The Isa Brown chicken is a beautiful and popular poultry breed. This comprehensive breed guide highlights why Isa Browns are popular with beginner and experienced chicken keepers.

Isa Browns are a dual-purpose breed with remarkable egg-laying ability, early maturity, adaptability, and friendliness.

Its beautiful look, body structure, and durability demonstrate the accurate breeding and genetics that make it successful.

Poultry enthusiasts must be cautious of health and environmental issues, notwithstanding their high productivity and efficiency.

As owners raise Isa Browns, understanding and managing their traits can maximize their potential.

With its rich history and distinctive characteristics, the Isa Brown chicken influences poultry farming by balancing productivity and friendship in backyards and commercial operations.

Bijaya Kumar
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