The purpose of this study was to compare the effects of dietary palm olein oil (POO) and Kilka fish oil (KFO) on yolk fatty acid content, ratio of fatty acids (FAs), antibody titre, and blood and yolk cholesterol of laying hens. One hundred White Hy-Line 26-wk-old (W-36) hens were allotted to 6 dietary treatments containing 0, 1.5, 3 and 4.5% POO or 2 and 4% KFO. The FAs and cholesterol content of yolk were measured at the end of three consecutive days of each period. Results reveal that the oleic acid increased and palmitic acid decreased (P<0.05) when hens were fed diets containing POO. The KFO diets reduced the blood cholesterol, yolk linoleic acid and yolk ω-6 FA (P<0.05), whereas the blood cholesterol increased by the supplementation of POO to dietary treatments. The yolk long chain polyunsaturated ω-3 FAs [Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)] increased as KFO was increased in diets (P<0.001). The diets supplementation of KFO and POO thus, showed a decrease and an increase in the ratio of ω-6/ ω-3 FAs (P<0.05), respectively. It is concluded that supplementation of KFO to the dietary treatment may improve deposition of ω-3 FAs; however, the POO supplementation may improve deposition of ω -9 FAs without alteration of yolk cholesterol.

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