If you have a flock of several chickens that are somewhat similar and introduce a new chicken breed that is somewhat dissimilar, the new addition may be subject to bullying for a period of time from other birds. But they can quickly get along well with other breeds. However, there are some exceptions. Some chicken breeds cannot coexist well with certain breeds. These chicken breeds basically don’t get along with each other. there are some birds that are not to be raised with other birds because they are calm and non-aggressive, and therefore they are vulnerable to attack by other birds. There are other birds that are not compatible with other breeds because they are aggressive and harm other birds. This is what we will explain in detail in the coming lines.
What Chicken Breeds Don’t Get Along?
Here is our list of some chicken breeds that we don’t recommend putting them with each other:
- Malay Roosters
- Old English Game Roosters
- Cornish Chickens
- Asil or Aseel Chickens
- American Game
- Modern Game Chickens
Below are clearer details of the reasons for their incompatibility with other birds.
Polish and other crested birds
Polish chickens are known for their attractive appearance due to the crest of feathers on the top of their heads.
Polish birds are very docile and can be easily tamed through gentle contact and the giving of treats. This has made them even more popular as show birds, suitable birds to keep with children, great for beginners, and pets for backyard chicken keepers.
The feathering of the head often reduces its visibility, making it easy to catch. It also causes their tendency to be fearful and introverted to avoid their dread. Polish and other crested birds are more problematic birds that should not be included in a mixed flock. Their large crests sometimes prevent them from seeing an attack coming and thus they are attacked and harmed by other birds.
Also, It is not preferable to mix Polish with other breeds, especially active breeds that like to control the herd, including Rhode Islanders, Welsumers and other strains that are alert, as it will harm them a lot.
In the event that you want to mix it with other birds, it is better to mix it with non-aggressive breeds such as: Orpingtons, silkies and bantam. You have also to cut their long head feathers first so that they do not get too long and reduce their visual capabilities.
A friendly chicken breed that loves cuddling, which makes them great with children. Their comical antics will draw you in and bring a smile to your face. It is a very nice bird that works even as its roosters are calm and non-aggressive. Its roosters are also known to be one of the most protective rooster breeds.
They are good birds in the yard and in confinement too and if allowed to move away from their range, you will find them good foragers. They don’t fly very well, and they do not attack others. This may make them a target and catch for more aggressive birds, and this may expose them to harm. Therefore, it is not preferable to combine them with other breeds in most cases.
If you want to combine them with other breeds, there are two strains that can be combined with them because they are somewhat calm and non-aggressive, they are Orpingtons and Mutt Easter Eggers.
They are the national birds of Malaysia and are known to be very feisty, and they do not behave well in confinement because they are very large and need large spaces to roam, so they should not be locked up because that increases their aggression and disturbing behavior.
It is also preferable that her barn be large enough to accommodate her large movement and be covered also because they can fly and may get out of the place. As we mentioned, it is an aggressive breed that attacks other birds, and is also known to attack humans so it should not be combined with other birds. 
While Malay chicks can be very calm and sensitive, adult Malays are tough and hardy and may be cruel to their chicks as well. It is not only aggressive with other birds, but it is prone to eating each other’s feathers.
Related Article: 3 Dumbest Chicken Breeds That You Need To Know..
Old English Game Roosters
It is among the oldest poultry breeds and is the first chicken breed developed in Britain. It was highly sought after by poultry farmers so Old English game chickens were sold at a high price. It was once raised for mainly cockfighting and is still used for this purpose in some areas. Old English Game Roosters were also known for their good looks and colorful plumage.
They have a strong, muscular build, broad shoulders, and hard, glossy plumage. This breed has always been a symbol of strength and endurance. They are usually friendly and deal well with people.
It is easy to maintain and handle. But since they are aggressive with other birds and fierce fighters. They may lead to bloody fights in most cases, so they must be separated from other breeds. However, they can be very docile and gentle with certain breeds, such as the Bantam.
If you are a beginner in raising chickens and want a strong-looking yet docile breed, the Old English Game is a better choice for you. Especially since it is very economical in terms of cost because its consumption of feed is low.
It is characterized by its large muscles, and it has a short neck and legs. While they look thin, their muscles are compact and The chickens of this breed weigh about 9 pounds. Therefore they are a good source of meat.
Cornish chickens are a breed with a reputation for an aggressive temperament and are known for their fighting abilities. This means that they will want to be at the head of the flock, and roosters will not be kind to meek, quiet breeds. If it is raised with other breeds, it will take over the barn and attack all other chickens.
Asil or Aseel Chickens
Asil falls under the category of Asian Hard Feather and is the oldest breed of game bird. The breed originated in the southern Punjab / Sindh region of India and Pakistan. It has a strong, muscular body whose main purpose to raise it for more than 2,000 years was to fight cocks.
A feisty breed, with the hens being aggressive with each other as well as the mature males fighting to the death. But In general, this strain is not aggressive towards humans.
Although their growth rate is very slow, when they mature they have compact and muscular bodies, and they are much heavier than they look. Therefore, Aseel chickens are very good for producing high quality meat.
But because of their aggressive qualities, it is not recommended to breed them with other breeds or take them as a pet, especially if you live near other people.
American games are famous for their large size and strong muscular structure, they weigh about 10 pounds, they can run very fast. It is most commonly used for shows and for decorative purposes. Some people use them to decorate their farms because they forage well and clean their environment. They pick up pests and insects making them hugely beneficial to farmers and ranchers.
Temperamentally, American Game chicken has a somewhat uncontrollable charm. As they are very proud of themselves, which makes them aggressive and do not back down from the fight.
It can express itself so strongly that she tends to speak, so it is easy to identify her mood and know if she is angry or not, as she will make a big fuss if she is not satisfied with something.
It is considered one of the most aggressive chicken breeds in the United States. So it should not be raised with other strains because it will certainly harm them. It may also not be the best choice if you are a beginner in poultry farming.
Saipan Jungle Fowl
This breed was bred as a fighting bird in far eastern Asia. Then they were brought to America later. It is a very colorful and attractive breed standing tall. Their strong, muscular appearance makes them resemble that of a Malay or Shamu.
They are very heat tolerant and are used to more humid and hot climates. Saipan Jungle Fowl is one of the most aggressive chicken breeds. They can be tamed, but they are usually aggressive with other animals that they do not recognize.
They are notorious for killing chickens and other animals. It may also attack humans to get food, So it is not recommended to have if you’ve children.