This study was conducted to investigate the changes of fatty acid composition of linoleic acid and/or linolenic acid enriched fertilized egg during incubation.
Sources of linoleic and linolenic acids were safflower oil(SO) and perilla oil(PO), respectively. Hens of each group were given diet added with 1) safflower oil 8%(SO 8%), 2) safflower oil 6% + perilla oil 2 %(SO 6% + PO 2%), 3) safflower oil 2% + perilla oil 6%(SO 2% + PO 6%) or perilla oil 8%(PO 8%). After 14 days of feeding experimental diets, the layers were artificially inseminated to obtain fertilized eggs. Eggs were sampled on the 15th, 17th, 19th and 21st day of incubation to determine the fatty acid contents in whole chick embryo.
Average weights of developing eggs were numerically decreased with extended incubation but there was no difference in egg weight due to dietary SO/PO level (p$gt;0.05). Linoleic acid(LA) content of eggs collected on the 2lst day were decreased 23.6, 47.5, 55.2 and 50.1% by SO 8%, SO 6% + PO 2%, SO 2% + PO 6% and PO 8% treatment respectively, compared with the value at 0 day.
The contents of linolenic acid(α-LNA) were 27, 113, 380 and 452 ㎎/embryo at 0 day and 30, 76, 157 and 227 ㎎/embryo at 21 day under the same dietary regimen. The result indicate 10% increase of α-LNA by SO 8% but respective 32.7, 58.7 and 49.8% decrease in other treatment. From the result, it was speculated that α-LNA was not catabolized in hens of SO 8% treatment, which contains the lowest level of ω-3 fatty acid but can be metabolized to either energy source or other metabolites in the hen of other treatment which have higher level of ω-3 fatty acid.
Arachidonic acid(AA) contents showed the same result as LA which were decreased 32.9, 44.1, 65.3 and 40.3% by each treatment compared to 0 day. Eicosapentaenoic acid(EPA) contents was 39.5% decreased by PO 8%, but was increased by the other treatment. It was assumed that chick embryos can not synthesize A.A, EPA and DHA from LA and α-LNA due to faster growth rates of embryos during developmental period. DHA content thought to be controlled by different regulation mechanism from that of A.A and EPA.
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