Abstract
This study was conducted to estimate genetic parameters for egg yolk cholesterol. Content of egg yok cholesterol was measured for a total of 473 hens of White Leghorn line. Cholesterol values were obtained from tee consecutively laid eggs when hens were 53 weeks of age. The yolk of each egg was weighted and freeze dried. Dried egg yolks were stored at -2$0^{\circ}C$ until analyzed. The results obtained from this study were as follows; 1. Yolk cholesterol content was measured in average $56.00\pm$0.194 mg/g dry yolk. 2. Heritability from the sire component of variance was $0.522\pm$0.215 and from the sire＋dam component of variance $0.33\pm$0.209. 3. Estimates of phenotypic correlation between your cholesterol and other factors such as body weight at 20 weeks of age, age at first egg, 40-week total egg number, egg Production rate: 53-week egg weight and 53-week yolk weight were -0.0208, -0.0321, -0.0378, -0.0834, 0.0790 and 0.1624, respectively. And genetic correlation coefficients for each item in the order were -0.5293, 0.7105, -0.4062, -0.0254, 0.2164 and 0.5027, respectively. 4. These results suggest the possibility that egg Yolk cholesterol should be reduced through selecting of sire families. To breed for low egg yolk cholesterol, it makes age at first egg earlier and enhances total egg number so that we can obtain the high rate of egg Production.
본 연구는 난황내 Cholesterol함양이 낮은 계통을 육성하기 위한 기초자료를 얻기 위하여 수행되었다. 실험에 이용된 공시재료는 White Leghorn계통의 53주령 된 473마리의 산난계에서 연적산란 된 3개의 알을 이용하였다. 각 알은 난황무게가 측정된 후 냉동 건조시켜 분석될 때까지 냉동고에 보관되었으며 분석된 결과는 다음과 같다. 1. 난황 Cholesterol함양은 평균 난황건물 g당 $56.00\pm$0.914 mg이었다. 2. 난황 Cholesterol함양의 유전력은 Sire분산성분만으로 추정된 것은 0.52, Sire＋Dam의 분산성분에 의한 것이 0.33으로 추정되었다. 3. 20주령체중, 초산일령, 총산난수, 산난율, 53주령난중, 53주령 난황무게와 난황 Cholesterol함양과의 표현형상관은 각각 -0.028,-0.0321, -0.0378, -0.0834, 0.0790, 0.1624로 나타났고, Sire성분에 의한 유전상관은 각각 -0.5293, 0.7105, -0.4062, -0.0254, 0.2164, 0.5027로 나타났다. 4. 본 연구의 결과를 종합해볼 때 난황 Cholesterol함양이 낮은 쪽으로 선발이 가능하며 이렇게 할 경우 초산일령 앞당길 수 있으며 총산난수를 증가시켜 높은 산난율을 얻을 수 있을 것으로 사료된다.