The effect of fish meal protein substitution with blood meal on performance of broilers was studied in a 2?5 factorial experiment and 6 replications. The experimental treatments were different levels of substitution (0, 25, 50, 75 and 100%) and age of broilers. (1 – 56 days and 21 – 56 days) Regardless of ration – fish meal were 7, 5 and 3 percent at any period. The main observations were daily weight gain, daily feed intake, feed conversion rate, protein efficiency ratio, carcass chemical components as well as cost during production period. Most feed intake was for 25 percent substitution which represented a significant difference (p < 0.05) with other treatments. Increasing level of blood meal to 75 percent resulted in significant (P > 0.05) effect on body weight, daily weight gain, but daily weight gain was reduced significantly (P < 0.05) in 100 percent substitution. Increasing level of blood meal in 50 and 75 percent substitution, increased feed conversion and protein efficiency ratio. The cost during production period for 50 percent substitution, in comparison with control, decreased 256 rials per Kg, which represented a significant difference ( P < 0.05 ).
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