Fish powder is a common food item for poultry diets in some countries. Some samples of fish powder cause severe gizzard ulcers in young birds. Because fish powder is an important part of diet of broilers, so it is necessary to test each samples of fish powder separately for growth poultry. For this purpose, the initial diet of 50 broilers should be free of fish powder for 5-7days. Then, the mixed with40% or 50% of the desired fish powder and given to the broilers for 7-10 days. And then kill poultry and their gizzard are examined based on these factors:

• Few ulcers, gizzard good color
• Few ulcers, to injury some parts of liners in gizzard
• Ulcers in some parts of gizzard, there are some crack in the thinner liner of gizzard.
• Severe ulcers, cracks and discoloration of the gizzard
• Filling the gizzard with bleeding.

  Fish powder is one of the good sources amino acids and its protein varies between 40%-70% and it is mostly used for feeding single stomachs such as poultry and some of the livestock. Fish powder contains high amounts of lysine, methionine and tryptophan.

The presence of unsaturated fats in fish powder cause this product is stored difficulty, because peroxidation of fats makes formation of substances such as aldehydes, which combine with some amines of proteins, thus reducing the availability of proteins and value of energy. Adding antioxidants such as ethoxyquin one to fish powder immediately after production can prevent the oxidation of fats. Also, when using fish powder, should be controlled in terms of bacterial contamination that cause diarrhea.