본 연구는 oil 형태의 conjugated linoleic acid(CLAzen 80)를 산란계 사료에 수준별로 첨가 급여하였을 때 산란율과 난황내 지방산 조성의 변화를 조사하기 위하여 수행하였다. 59주령의 산란계 72수를 완전임의배치법으로 4개 처리구에 6주간 공시하였다. 처리구는 CLAzen 80를 첨가하지 않은 대조구와 각각 1, 2 및 $3\%$를 첨가구를 두었다. 연구 결과를 살펴보면 산란율은 처리구별 통계적 유의차가 없었지만, 난황내 지방산 조성은 CLAzen 80 첨가에 의하게 크게 영향을 받았다. 난황내 C16:0과 C18:0과 같은 포화 지방산 함량은 CLAzen 80 첨가에 의하여 증가하였으나, 일가불포화지방산인 C18:1 함량은 오히려 감소하였다. 한편, 난황내 C18:2와 C18:3와 같은 다가불포화지방산은 CLAzen 80 급여 2$~$4주사이에는 모든처리구들에 있어서 그 함량이 일정하게 유지되었다. 그러나, 대조구와 비교하여 CLAzen 80 급여 6주 째에는 난황내 C18:2 함량이 감소하였다. 불포화지방산:포화지방산 비율과 n-6:n-3 불포화지방산 비율은 2$~$4주 사이에는 처리구별간에 통계적 유의차가 없었고, 6주째 불포화지방산:포화지방산 비율이 CLAzen 80 첨가에 의하여 감소하였다. 한편, 난황내 CLA 함량은 CLAzen 80 첨가수준에 비례하여 증가하였다. 따라서, 산란계 사료 내 CLAzen 80 첨가는 난황내 CLA 함량을 증진시키는 것으로 요약할 수 있다.
The objectives of the present study were to investigate the effects of varying levels of dietary oil containing conjugated linoleic acid (CLA) on the egg production and fatty acid composition of egg yolk. Seventy-two 59-wk-old ISA Brown laying hens were randomly allotted to four dietary treatments, each consisting of three replicates with six birds per replicate. There were four treatments that consist of diets containing 0, 1, 2, or $3\%$ commercial CLA-containing oil. Egg production was not significantly different among the dietary treatments at 0, 2, 4, and 6 week. The proportion of saturated fatty acids such as C16:0 and C18:0 in egg yolk were increased, but that of monounsaturated fatty acid C18:1 was decreased by feeding CLA-containing oil supplementation. However, the proportion of polyunsaturated fatty acids such as C18:2 and C18:3 in egg yolk were not different among dietary treatments at 2 and 4 wk of the experiment. At 6 week, the proportion of C18:2 in egg yolk was decreased by feeding CLA-containing oil compared with the control. Polyunsaturated fatty acid:saturated fatty acid (P:S) ratio and n-6:n-3 polyunsaturated fatty acid ratio were similar across the treatments between 2 and 4 week. The P:S ratio was decreased by dietary CLA-containing oil supplementation at 6 week. The proportion of CLA in egg yolk was linearly increased with increasing levels of CLA-containing oil supplementation. In conclusion, dietary supplementation of CLA-containing oil to laying hens increased beneficially increased CLA content in their egg yolk.
