The objective of this study was to assess the influence of fish oil (FO) in two different levels of protein on growing broilers and some blood parameters.The birds were fed a common control diets, in the pre-starter phase (1 to 7 d), and from d 8 on, 480 birds were assigned to 8 dietary groups and received the diets supplemented with 0, 1.5, 3, or 6 % FO with two dietary crude protein (CP) level (21.5 and 19.5% for grower & finisher phases, respectively) and 10% diluted CP (19.35 and 17.55 for grower & finisher phases, respectively), throughout a 35-d growth period.. Body weight gain (BWG), daily BWG, feed conversion ratio (FCR) and feed intake were measured. The birds slaughtered after blood sampling. The FCR were improved in the groups treated with fish oil. Highest final BW, highest daily BW gain, and best FCR were recorded for the 1.5% FO dietary group. A 10% reduction in dietary CP level decreased the weight gain and feed intake of chickens. Feed conversion ratio of chicks fed the crude protein diluted diets was higher (P<0.05) than chicks fed recommended CP level. In addition, with increasing levels of FO in the broiler diets, the blood glucose (G) level increased, total protein (TP), albumin (A) and globulin (GL) concentrations decreased.
