Heritability Estimation Of Continuous Egg Production Traits And Performance Analysis Of Crossbreeds By S3 Line Selected From Wannan Yellow Chicken

Indigenous chickens,haven’t under systematic selection,exhibited low reproductive performance.In order to evaluate the egg production performance of local chickens and the production performance when hybrid with other lines,S3 line from Wannan yellow chicken were selected for egg production heritability estimation with egg production records for three generations.S3 line was also crossbred with H1 and H2 lines to form four combinations as S1（?）×（H1（?）×S3（?））（group 1）,S1（?）×（H2（?）×S3（?））（group 2）,S1（?）×（S3（?）×H2（?））（group 3）so as to provide a practical commercial combination.1.Estimation of genetic parameters of continuous production traits and their correlationsThe sire heritability of continuous production traits is low in Wannan yellow chicken S3line.,The heritability of egg number is 0.134-0.247,average clutch length is 0.010-0.167,maximum clutch length is 0.063-0.151,the average pause length is 0.0004-0.105 and the maximum pause length is 0.0004-0.070.The sam heritability of continuous production traits is relatively high,among which the heritability of laying at early stage（23-27 weeks of age）is 0.435 eggs,average clutch length is 0.543,maximum clutch length is 0.529,average pause length is 0.476,and maximum pause length is 0.477.The heritability of laying at peak（28-32 weeks of age）is 0.541,the average clutch length is 0.248,the maximum clutch length is 0.302,the average pause length is 0.072 and the maximum pause length is 0.081.The correlation among continuous production traits showed that the egg number was positively correlated with the average clutch length and maximum clutch length（P<0.01）,and was negatively correlated with the pause length and maximum pause length（P<0.01）.2.Performance analysis of crossbreeding by using Wannan yellow chicken S3 strain When crossbred with H1 and H2,the egg weight of group 3（49.76 g）and group 1（50.04g）was significantly higher than that of group 2（48.26g,P<0.05）.The height of dense albumen and Haulf unit were significantly higher in group 1（8.74 mm,95.56,respectively）and group 3（9.11 mm,97.14,respectively）as compared with group 2（8.21mm,93.35,respectively,P<0.05）.The egg yolk fat content in group 1（16.05%）and group 3（15.85%）was significantly higher than that of group 2（14.81%,P<0.05）.Crude protein in egg white was significantly higher in group 1（9.17%）as compared with that of group 2（8.97%）and group 3（8.94%,P<0.05）;The dry matter of egg white in group 1（10.94%）and group 3（10.81%）was significantly higher than that in group 2（10.38%,P<0.05）.Egg yolk cholesterol in group 2（14.60/mg/g）was significantly higher than that in group 1（8.17/mg/g,P<0.05）.Live weight of male chickens was higher in group 3（1.25 kg）than that of group 2（1.16kg,P<0.05）.Meat quality analysis showed that the PH of breast muscle was 5.87 in group 3,which was significantly higher than that of group 2（5.74,P<0.05）.The L*₂₄of leg muscle was 49.66 in group 1,which was significantly higher than that of group 3（44.66,P<0.05）.The cooking loss of leg muscles in group 2（7.54%）was significantly higher than that in group 3（5.00%,P<0.05）;The cooking loss of breast muscle in group 2（8.32%）was significantly higher than that of group 1（5.62%）.The heritability of Wannan yellow chicken S3 line was lower in sire family and higher in female.The crossbred of S1（?）×（H1（?）×S3（?））showed higher meat and egg quality.