本 硏究의 目的은 肉用種鷄 父系統과 母系統에 있어서 4週齡時 體重(BW), 32 週齡時 卵幅(EB), 卵長(EL), 卵重(EW), 卵形指數(SI) 및 38週齡까지의 産卵數(EN)에 대한 遺傳的 母數 推定으로서 供試材料로는 韓協家禽育種農場에서 飼育되고 있는 父系統 C line 및 母系統 G line으로서 總 1,193首의 82年度 성적을 分析하였다.
1. 一般能力에 있어서 C系統의 體重, 卵幅, 卵長, 卵形指數, 卵重 및 産卵數에 대한 平均은 各各 668.34g±47.18, 4.23㎝±0.11, 5.49㎝±0.19, 77.06%±2.98, 55.73g±3.54 및 59.72個±13.39이며, G系統에서는 487.89g±41.43, 4.22㎝±0.11 5.51㎝±0.19, 76.72%±3.20, 55.43g±3.26 및 76.93個±12.77이었다. 産卵數에 대한 變異係數는 다른 形質보다 컸다.
2. 遺傳力은 父分散成分, 母分散成分 및 父母分散成分으로부터 各各 求하였으며 C系統에 있어서 父母分散成分으로부터 推定된 遺傳力은 體重, 卵幅, 卵長, 卵形指數, 卵重 및 産卵數에 대해 0.30, 0.29, 0.40, 0.22, 0.45, 0.60으로 各各 推定되었고 G系統에서는 0.33, 0.23, 0.28, 0.13, 0.49 및 0.33으로 各各 推定되었다.
3. 各 形質間의 相關關係는 C와 G系統이 비슷한 傾向을 나타내었다. 比較的 높은 正의 相關은 卵重과 卵幅間(C ; 0.99, G ; 0.94), 卵重과 卵長間(C ; 0.75, G ; 0.82) 및 卵幅과 卵長間(C,G;0.58)에 나타났다. 높은 負의 相關은 卵形指數와 卵長間(C ; -0.70, G ; -0.65)에 나타났으며 卵形指數와 卵重間에는 낮은 負의 相關(C ; -0.11, G ; -0.19)이 推定되었고 卵形指數와 産卵數 間에는 낮은 正의 相關(C ; 0.25, G ; 0.17)을 보였다. 다른 形質들 間에는 2系統 모두 낮은 正 또는 負의 相關이 나타났다.
孵化率과 卵形指數間에는 높은 正의 表現型 相關(0.63)이 推定되었으며 孵化率에 대한 卵形指數의 回歸는 Y=-216.77+7.6216X-0.0146939X²의 二次式으로 推定되었다.
Present study was carried out to estimate phenotypic and genetic parameters influencing body weight(BW) at 4 weeks of age, egg breadth(EB), egg length(EL), egg shape index(SI) and egg weight(EW) at 32 weeks of age and egg numbers(EN) up to 38 weeks of age in broiler male and female lines.
The data were collected from closed White Plymouth Rock(female line; G) and Cornish(male line; C) flocks involving 1193 pullets from 211 dams and 48 sires in 1982.
The results obtained are summarized as follow;
1. General performance for various traits of lines C and G.
The means and standard deviations of BW, EB, EL, SI, EW and EN were 668.34±47.18, 4.23±0.11, 5.49±0.19, 77.06±2.98, 55.73±3.54 and 59.72±13.39 in line C, respectively and 487.89±41.43, 4.22±0.11, 5.51±0.19, 76.72±3.20, 55.43±3.26 and 76.93±12.17 in line G, respectively.
2. Heritability
Heritabilities were estimated from sire, dam and combined components. Estimates for BW, EB, EL, SI, EW and EN from combined components were 0.30, 0.29, 0.40, 0.22, 0.45 and 0.60 in line C, respectively and 0.33, 0.23, 0.28, 0.13, 0.49 and 0.33 in line G, respectively.
3. Correlation
Genetic and phenotypic correlations showed similar trend in line C and G. Genetic correlations, estimated EW with EB and EL, were high and positive(line C; 0.99, 0.75, respectively and line G; 0.94, 0.82, respectively), also correlation of EB with EL was 0.58(both lines; 0.58). High and negative genetic correlations were shown between SI and EL in line C and G(-0.70, -0.65, respectively). Genetic correlations between SI and EW were relatively low and negative in line C and G(-0.11; -0.19, respectively) and between SI and EN were relatively low and positive in line C and G(0.25, 0.17, respectively).
Between other traits, low genetic correlations were shown in both lines. High and positive correlation was estimated between hatchability and egg shape index and polynomial regression of egg shape index on hatchability was estimated; Y=-216.77+7.6216X-0.0146939X².