本 硏究에서는 産卵種鷄 育種開發에 必要한 基礎資料를 얻기 위하여 産卵種鷄 6系統을 兩面交雜시켜 生産된 後代 3.759首를 가지고 交雜에 의한 雜種强勢效果와 結合能力을 推定하였다.
供試鷄는 國立種畜院 大田支院에서 保有하고 있는 White Leghorn 種 6系統에서 生産된 36個 組合의 兩面交雜種을 利用하여 1984年5月11日부터 1985年9月23日까지 500日間 遂行하였으며, 受精率, 孵化率, 育雛率, 育成率, 成鷄生存率, 初産日齡, 初産時體重, 平均卵重, 生存鷄産卵率, 産卵指數 및 飼料要求率 等을 調査하였다. 調査된 各 形質에 대한 記錄을 分析하여 交雜에 의한 雜種强勢效果, 一般結合能力, 特殊結合能力, 相反交雜效果 等을 推定하였다.
分析方法은 Griffing (1956)의 Model Ⅰ 模型을 利用하여 推定하였다.
本 硏究에서 얻어진 結果를 要約하면 다음과 같다.
1. 調査된 形質의 一般能力은 受精率이 94.76%, 孵化率이 74.05%, 育雛率이 97.47%, 育成率이 99.72%, 生存率이 93.81%, 初産日齡이 150日, 初産時體重이 1,505g, 平均卵重이 60.08g, 生存鷄産卵率이 77.11%, 産卵指數가 269.8個, 飼料要求率이 2.44로 나타났다.
2. 雜種强勢의 크기는 受精率에서 -1.66%로 負의 方向으로 나타났으며 孵化率에서 9.58%, 育雛率에서 0.26%, 生存率에서 1.83%, 初産日齡에서 -3.87%, 初産時體重에서 3.63%, 平均卵重에서 0.96%, 産卵率에서 4.23%, 産卵指數에서 6.4%, 그리고 飼料要求率에서 -0.85%로 나타나 受精率과 體重을 제외한 모든 形質에서 바람직한 改良方向으로 雜種强勢效果를 보여 주었으며, 比較的 遺傳力이 낮은 孵化率, 産卵能力에서는 雜種强勢效果가 컸고, 遺傳力이 比較的 높은 卵重은 雜種强勢效果가 적었다.
3. 結合能力의 分析에서 얻어진 結果는 다음과 같다.
1) 受精率의 一般結合能力, 特殊結合能力 및 相反交雜效果는 重要하지 않는 것으로 나타났으며, 受精率은 遺傳的 要因보다는 環境的인 要因에 의해 影響을 많이 받는 것으로 나타났다. 孵化率에서는 一般結合能力이 큰 比重을 차지하였으며 특히 K와 V系統의 相加的 遺傳效果가 크게 推定되었다.
2) 育雛率과 成鷄生存率은 特殊結合能力과 相反交雜效果가 重要한 것으로 나타났으며 K×A, A×K의 交配組合이 優秀하였다.
3) 飼料要求率과 平均卵重은 一般結合能力이 특히 重要하였으며 特殊結合能力과 相反交雜效果도 重要하게 나타났다. 飼料要求率은 F, K, B 계통에서 優秀하였으며, 卵重은 F, B 系統이 優秀하게 나타났다.
4) 初産日齡은 一般結合能力, 特殊結合能力 및 相反交雜效果가 모두 重要하게 나타났으며, V×E, F×K, B×F의 交配結合이 優秀하였고, 初産時體重은 一般結合能力이 특히 重要하게 나타났으며 特殊結合能力과 相反交雜效果도 重要하게 나타났다. 初産時體重을 가벼운 쪽으로 改良하고자 할 때 K, F, E 系統이 優秀하였다.
5) 産卵率과 産卵指數는 一般結合能力, 特殊結合能力, 相反交雜效果가 모두 重要하였으며, F×K, A×K, K×A組合에서 優秀하게 나타났다.
4. 一般的으로 一般結合能力이 重要하게 나타난 形質은 孵化率, 初産時體重, 平均卵重, 産卵率, 産卵指數, 飼料要求率이었고 特殊結合能力이 重要하게 나타난 形質은 育雛率, 成雛生存率, 初産日齡, 産卵率, 産卵指數였으며, 相反交雜效果가 重要하였던 形質은 初産日齡이었다.
The subject of this study was to obtain some genetic information for developing superior layer chickens. Heterosis and combining ability effects were estimated with 3,759 progenies of full diallel crosses of 6 strains in White Leghorn. Fertility, hatchability, brooder-house viability, rearing-house viability, laying-house viability, age at 1st egg laying, body weight at 1st egg laying, average egg weight, hen-day egg production, hen-housed egg production, and feed conversion were investigated and analyzed into heterosis effect, general combining ability, specific combining ability and reciprocal effect by Griffing's model I.
The results obtained were summarized as follows;
1. The general performance of each traits was 94.76% in fertility, 74.05% in hatchability, 97.47% in brooder-house viability, 99.72% in rearing-house viability, 93.81% in laying-house viability, 150 day in the age at 1st egg laying, 1,505g in the body weight at 1st egg laying, 60.08g in average egg weight, 77.11% in hen-day egg production, 269.8 eggs in hen-housed egg production, and 2.44 in feed conversion.
2. The heterosis effects were estimated to - 0.66%, 9.58%, 0.26%, 1.83%, -3.87%, 3.63%, 0.96% 4.23%, 6.4% and -0.81% in fertility, hatchability, brooder-house viability, laying-house viability, the age at 1st egg laying, the body weight at 1st egg laying, average egg weight, hen-day egg production, hen-housed egg production and feed conversion, respectively.
3. The results obtained from analysis of combining ability were as follows;
1) Estimates of general combining ability, specific combining ability and reciprocal effects were not high in fertility. It was considered that fertility was mainly affected by environmental factors. In the hatchability, the general combining ability was more important than specific combining ability and reciprocal effects, and the superior strains were K and V which the additive genetic effects were very high.
2) In the brooder-house viability and laying-house viability, specific combining ability and reciprocal effects appeared to be important and the combinations of K × A and A × K were very superior.
3) In the feed conversion and average egg weight, general combining ability was more important compared with specific combining ability and reciprocal effects. On the basis of combining ability the superior strains were F, K and B in feed conversion, F and B in the average egg weight.
4) General combining ability, specific combining ability and reciprocal effects were important in the age at 1st egg laying and the combination of V × F, F × K and B × F were very useful on the basis of these effects. In the body weight at 1st egg laying, general combining ability was more important than specific combining ability and reciprocal effects, relatively. The K, F and E strains were recommended to develop the light strain in the body weight at 1st egg laying.
5) General combining ability, specific combining ability and reciprocal effects were important in the hen-day egg production and hen-housed egg production. The combinations of F × K, A × K, and K × A were proper for developing these traits.
4. In general, high general combining ability effects were estimated for hatchability, body weight at 1st egg laying, average egg weight, hen-day egg production, hen-housed egg production, and feed conversion and high specific combining ability effects for brooder-house viability, laying house viability, age at 1st egg laying, hen-day egg production and hen-housed egg production, and high reciprocal effects for the age at 1st egg laying.