Abstract
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 trails of lines C and G. The means and standard deviations of BW, EB, EL, SI, EW and EN were 668.34${\pm}$47.18, 4.23${\pm}$0,11, 5.49 ${\pm}$0.19, 77.06${\pm}$2.98, 55.73${\pm}$3.54 and 59.72${\pm}$13.39 in line C, respectively and 487.89${\pm}$ 41.43, 4.22${\pm}$0.11, 5.51${\pm}$0.19, 76.72${\pm}$3.20, 55.43${\pm}$3.26 and 76.93${\pm}$12.17 in line G, respectively. 2. Heritability Heritabilities were estimated from sire, dam and combined components. Estimates for BW, EB, EL, SI, EW and EN from combined components were 0.30, 0.29, 0,40, 0.22, 0.45 and 0.60 in line C, respectively and 0.33, 0.23, 0.28, 0.13, 0.49 and. 0.33 in line G, respectively. 3. Correlation Genetic and phenotypic correlations showed similar trend in line C and G. Genetic correlations, estimated EW with EB and EL, were high and positive (line C; 0.99, 0.75, respectively and line G; 0.94, 0.82, respectively), also correlation of EB with EL was 0.58 (both lines; 0.58). High and negative genetic correlations were shown between SI and EL in line C and G (-0.70, -0.65, respectively). Genetic correlations between SI and EW were relatively low and negative in line C and G (-0.11, -0.19, respectively) and between SI and EN were relatively low and positive in line C and G (0.25, 0.17, respectively). Between other traits, low genetic correlations were shown in both lines, High and positive correlation was estimated between hatchability and egg shape index and polynomial regression of egg shape index on hatchability was estimated; Y=-216.77＋7.6216X-0.0146939X$^2$.
본 연구의 목적은 육용종계 부계통과 모계통에 있어서 4주령시 체중(BW), 32주령시 란폭(EB), 란장(EL), 란중(EW), 란형지수(SI) 및 38 주령까지의 산란수(EN)에 대한 유전적 모수 추정으로서 공시재료로는 전협가금육극농장에서 사육되고 있는 부계통 C line 및 모계통 G line으로서 총 1,193수의 82년도 성적을 분석하였다. 1. 일반능력에 있어서 C계통의 체중, 란폭, 란장, 란형지수, 란중 및 산란수에 대한 평균은 각각 668.34g$\pm$47.18, 4.23cm$\pm$0.11, 5.49cm$\pm$0.19, 77.06%$\pm$2.98, 55.73g$\pm$3.54 및 59.72개$\pm$13.39이며, G계통에서는 487.89g$\pm$41.43, 4.22cm$\pm$0.11, 5.51cm$\pm$0.19, 76.72%$\pm$3.20, 55.43g$\pm$3.26 및 76.93개$\pm$12.77이었다. 산란수에 대한 변이계수는 다른 형질보다 컸다. 2. 유전력은 부분산성분, 모분산함분 및 부모분산성분으로부터 각각 구하였으며 C계통에 있어서 부모분산성분으로부터 추정된 유전력은 체중, 란폭, 란장, 란형지수, 란중 및 산란수에 대해 0.30, 0.29, 0.40, 0.22, 0.45, 0.60으로 각각 추정되었고 G계통에서는 0.33, 0.23, 0.28, 0.13, 0.49 및 0.33으로 각각 추정되었다. 3. 각 형질간의 상관관계는 C와 G계통이 비슷한 경향을 나타내었다. 비교적 높은 정의 상관은 란중과 란폭간(C; 0.99, G; 0.94), 란중과 란장간(C; 0.75, G; 0.82) 및 란폭과 란장간(C,G; 0.58) 에 나타났다. 높은 부의 상관은 란형지수와 란장간 (C; -0.70, G; -0.65)에 나타났으며 란형지수와 란중간에는 낮은 부의 상관(C; -0.11, G; -0.19)이 추정되었고 란형지수와 산란수 간에는 낮은 정의 상관(C; 0.25, G; 0.17)을 보였다. 다른 형질들 간에는 2계통 모두 낮은 또는 부의 상관이 나타났다. 부화율과 란형지수간에는 높은 정의 표현형 상관(0.63)이 추정되었으며 부화율에 대한 란형지수의 회귀는 Y=-216.77＋7.6216$\times$-0.0146939X$^2$의 이차식으로 추정되었다.