The objective of this study was to determine the effect of dietary oils on the levels of the γ-linolenic acid in chicken meat lipids. Three hundred ten five, 1-d old, male, Ross strain, broiler chicks were fed for 35 d to compare diets containing evening primrose oil(EPO) and hemp seed oil(HO) to a control diet. Fatty acid composition of lipid from chicken skin, thigh and breast muscle were determined at the end of the trial. The level of γ-linolenic acid of lipids from chicken meat fed diets containing EPO or HO was significantly higher than that of the control group(p〈0.05). The level of γ-linolenic acid of lipids from chicken skin was highest in the group, which had been fed the EPO 0.85%, followed in order by EPO 0.7%, 0.5%, EPO mixed oil, HO and HO mixed oil. There was a significant difference in the level of γ-linolenic acid of chicken skin between the control and treatment groups(p〈0.05). The level of γ-linolenic acid of lipids from chicken thigh muscle was also similar to skin, and significantly higher than that of the control group(p〈0.05). The level of γ-linolenic acid of lipids from chicken breast muscle was highest in the group, which had been fed the EPO 0.5%, followed in order by EPO 0.7%, 0.85%, HO 0.5% and HO mixed oil. There was a significant difference in the level of γ-linolenic acid of chicken breast muscle between the control and treatment groups(p〈0.05).

The objective of this study was undertaken to investigate changes in fatty acid profile of breast and thigh muscle of old laying hens as transferred from cage to backyard raising system and to provide basic information on using old laying hens to producers for environmental managements. Overall, percentages of unsaturated fatty acid obtained from breast and thigh muscle with cage and backyard raising system are the most abundant, followed by saturated fatty acid. For breast muscle, there were no differences (P>0.05) between cage rearing system and backyard raising system in saturated fatty acid (SFA) and mono unsaturated fatty acid (MUFA). Poly unsaturated fatty acid (PUFA) and PUFA:SFA ratios were significantly higher in backyard raising systems in comparison with cage rearing systems (P<0.05). No differences (P>0.05) were detected between both rearing systems for MUFA, PUFA, and PUFA:SFA ratios with thigh muscles. SFA in thigh muscle was significantly (P<0.05) higher in cage rearing systems compared with backyard raising systems. In conclusion, using breast and thigh muscle meats from old laying hens as functional foods or investigating impact assessment on the improvement of farm management system may serve as a good management practice to encourage producers.