A broiler is any chicken that is bred raised specifically for meat production. Most commercial broilers reach slaughter weight between 4-7 weeks of age.

The amount of amino acids in the diet of broilers are different in pre-start and grower ration and final birdseeds. The amount of protein and amino acids are consumed by bird, can affect growing birds’ feather. Feathers contain about 90% crude protein,60% of which are amino and also cystine contain about 7% of feather protein. Most feather structure is composed of creatine protein, which is produced in epidermal cells.

Creatine is rich in cysteine and each of molecule has about 8.5 cystine. So the presence of amino acids that have sulfur like methionine is necessary to built good feathers. Low level of methionine and cystine cause abnormal feather growth. Also, when amino acid isn’t enough, so primary feathers are in form of spoon-shaped.

A broiler chicken should be fed high protein food and this feed should be contain enough protein to support rapid growth and help broiler chickens reach market weight efficiently.

The firmness of the skin is depending on the amount of collagen, so the skin that has more collagen is less prone to tearing. So, any nutritional factor that affects the amount of skin collagen will also indirectly affect the tearing of birds.