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The aim of this work was to evaluate sex effect on behavior of two commercial broilers lines. Productive parameters, carcass composition and yield, amount and quality of fat deposited in the meat and skin and total body fat were studied. A completely randomized design with four treatments (MR-Male Ross, HR-Female Ross, MAF-Male Avian Farm and HAF-Female Avian Farm) and eight repetitions of 40 chickens was used. Animals received water and food ad libitum. After 50 days, two birds (a male and a female) per repetition were chosen at random and slaughtered for carcass evaluation. Samples of breast, leg, skin and abdominal fats were analyzed to determine the percentage of intramuscular fat, total cholesterol and fatty acid composition. The Ross line showed higher final weight and weight gain, better intake and feed conversion rate. Also, it was observed that females of both lines had similar results in relation to these parameters. Better yield of breast with bone was found in Ross males and females. In relation to legs and thigh, Ross males showed better results and no differences were observed among females of both lines. Males deposited less fat than females. Finally, differences in percentage of intramuscular fat, content of cholesterol in breast with skin, leg with skin and skin, percentage of saturated, mono and polyunsaturated fatty acids were observed between sex and lines.

The effect of three different lipid sources (soybean oil, chicken oil or bovine fat) on the abdominal fat fatty acid composition in 50 day-old broiler chickens was evaluated. A completely randomized design was used, with 4 treatments, 8 repetitions and 40 Arbor Acres broiler chicks of each sex. The four treatments were isocaloric and isoproteic with the following characteristics: T1 Control (Soybean-corn); T2 Control + 3% soybean oil; T3 Control + 3% chicken oil; and T4 Control + 3% bovine fat. The lipids from the diets had significantly statistical effects (p<0,05) on the fatty acid composition of broiler abdominal fat. Multivariate techniques also showed differences in fatty acid composition within treatments due to sex. The studied dietary lipids affected the polyunsaturated/saturated fatty acid ratio (P/S) but had only small effects on the n-6: n-3 fatty acid ratio