| In order to investigate the characteristics of egg quality traits and the effects of the candidate genes related to them in Wenshang Barred chickens,the 13 egg quality indexes of egg weight,egg shape,shell thickness,shell strength,albumen height,yolk color,Haugh unit,weights and rations of albumen,yolk and shell were determinated for layers at the age of 30 weeks,40 weeks and 50 weeks.Then the same indexes from different ages of weeks were compared,and the correlations between egg quality traits at the same age of weeks were calculateed.Finally,22 SNPs in 14 egg quality candidate genes were genotyed,and the association analysis of SNPs with egg quality traits were conducted.The main results of the study are as follows:(1)This study found that the egg weight,egg yolk weight,egg shell weight,protein weight,and egg yolk ratio increased significantly(P<0.05),and the thickness and protein ratio of eggshell decreased significantly(P<0.05)with the increase of week age(P<0.05),and the proportion of Kazakhstan units and eggshells at the age of 30,40 week was obvious.At the age of 50 weeks(P<0.05),the intensity of eggshell and yolk color at 30 weeks old were significantly higher than that of 40 weeks and 50 weeks(P<0.05),and the egg shape index of40 weeks and 50 weeks old was significantly higher than that of 30 weeks(P<0.05),and the height of protein at 30 weeks and 50 weeks old was significantly higher than that of 40 weeks(P<0.05).(2)The correlation between different age groups was consistent.The egg weight of 30,40 and 50 weeks was positively correlated with egg yolk weight,eggshell weight,protein weight and egg yolk ratio;30,40 and 50 weeks old eggshell thickness was positively correlated with eggshell strength,eggshell weight and egg shell proportion;30,40 and 50 weeks old protein weight was negatively correlated with egg yolk ratio and egg shell ratio;30,40,50.The proportion of egg yolk and eggshell proportion were negatively correlated with protein ratio.(3)22 SNPs of the 14 genes of genotyping,ss538155652,rs16544657 and rs15009190 are polymorphic in the population and are reported in the literature.All the other SNPs are new discoveries.The results showed that the GG type eggshell thickness at G6612 A site of OCX gene was significantly higher than that of AA for 30,40,and 50 weeks old,and the CC type protein at rs13968880 site of ENOX1 gene was significantly higher than that of TT type.For30,40 weeks,the T6101 C locus of the OCX gene was TT,and the TC type protein was significantly higher than that of the TT type.CC type,ENOX1 gene rs13968880 locus TT egg yolk weight,egg yolk ratio is significantly higher than the TC and CC type.For 30,50 weeks old,OCX gene G6612 A site GG,GA type shell thickness is significantly higher than AA type,G7158 A site thickness is significantly higher than the type,protein height and haugh unit are significantly higher than those The weight of CA type protein at 642 A site was significantly greater than that of CC type.(4)The SNPs,which had significant influence on the quality of egg,calculated its contribution to the phenotypic variance(CPV).The results showed that the T6101 C of the OCX32 gene and the height of 30 weeks protein,the weight of the egg yolk,the proportion of egg yolk,the protein proportion,the egg weight and the protein weight of 40 weeks,and the protein height of the 40 weeks were significantly correlated with the haugh unit(P<0.05).Its phenotypic contribution was 3.84%-7.09%,and the G6612 A of the OCX32 gene was significantly correlated with the 30 weeks eggshell ratio,eggshell thickness,protein height,protein ratio,50 weeks eggshell thickness and protein height(P<0.05),and its phenotypic contribution was 3.25%-5.35%;the G7158 A of the OCX32 gene and the thickness of eggshell,the proportion of eggshell,the ratio of protein,and the ratio of egg shell to 30 weeks were 50.The thickness of eggshell was significantly correlated with the height of protein(P<0.05),and its phenotypic contribution was 2.87%-7.45%.The rs314570368 of the CA7 gene was significantly correlated with the thickness of eggshell and haugh unit at 30 weeks of age.The contribution rate of the gene to its phenotype was 11.05% and 10.52%,respectively.rs14964613 was significantly correlated with the number of egg shaped fingers of 40 weeks(P<0.05).The contribution rate was 7.92%;the C642 A of FSH? was significantly correlated with egg weight and protein weight at 30 week age(P<0.05),and the contribution rate to phenotype was 10.08% and 10.40% respectively.The rs14966715 of CDH13 gene wassignificantly related to egg weight,egg shape index and yolk weight of 30 weeks old(P<0.05),and the percentage of phenotypic contribution was 4.95%-6.23%.The rs316056011 of the ENOX1 gene was significantly correlated with the egg shape index and yolk weight of 30 weeks,and the protein ratio of 40 weeks(P<0.05).The percentage of its phenotypic contribution was 2.42%-4.20%,rs13968880 and 30 weeks of egg yolk weight.The proportion of egg yolk and protein,40 weeks egg yolk weight,egg yolk proportion,protein proportion,50 weeks protein height significantly correlated(P<0.05),the phenotypic contribution rate was3.78%-9.30%,ZNF536 gene was significantly correlated with 30 weeks old protein weight,and its phenotypic contribution rate was 3.77%;OIH gene A138 G was significantly related to the 40 week egg shape index(P<0.05),the contribution rate to its phenotype was 2.88%,and the C6461 T of the NCAPG gene was significantly correlated with the weight of 50 weeks old egg and protein weight(P<0.05),and its phenotypic contribution was 9.65% and 9.36%,respectively.To sum up,the egg quality characters were significantly changed with the increase of the week age in Wenshang Barred chickens.Eggshell thickness was positively correlated with eggshell strength,eggshell weight and eggshell ratio at the ages of 30,40,50 three weeks;SNPs in OCX32,CA7,FSH?,CDH13,ENOX1,ZNF,OIH and NCAPG have significant effects on egg quality,which would be valuable markers for molecular marker-assisted selection of egg quality traits in the future. |
PDF Full Text Request