A study was conducted to evaluate the nutritive value and inclusion level of sunflower seed (SFS) in broiler diets. SFS contained 38.7% ether extract (EE), 16.9% CP, 14.9% crude fiber (CF), 3.5% ash, 0.57% lysine, and 0.46% methionine (89.2% DM basis). The AME (kcal/ kg) content of SFS in roosters was 5,225 and in broilers at 4, 18, and 35 d of age was 3,493, 5,132, and 5,162, respectively. The CP, EE, and CF digestibilities were 80.4, 71.2, and 11.4%, respectively. In an isocaloric and isonitrogenous diet containing SFS at 0, 5, 10, 15, and 20%, SFS up to 20% did not affect weight gain and feed consumption, but the feed conversion ratio was improved (P < 0.05) when broilers were fed 15 or 20% SFS in the starter and finisher diets. CF digestibility of starter diet was significantly lower when 15 or 20% SFS was included. CF digestibility of the finisher diet and digestibility of other nutrients in starter and finisher diets were comparable in all treatment groups. Liver and muscle lipid content, plasma total and high-density lipoprotein cholesterol content, muscle cholesterol content, dressing percentage, liver weight, and giblet weight (as % live weight) were comparable among all treatment groups. Abdominal fat was increased in birds fed 20% SFS. Percentage skin was decreased in broilers fed ≥10% SFS.
