On The SNPs In The Chicken Genes And Their Association With The Egg Performance Of Laying Hen

Egg is one of the excellent sources to supply protein for human being, and China has been the top country with the highest egg production in the world for several years. Egg performance is, in one hand, the important trait in the breeding of chicken and in other hand, has large effect on the efficiency in chicken egg production. It is one of the most important topics for how to improve the egg performance by using the molecular biological technology newly-developed. In this research, a population including 399 individuals with 11 traits recorded, which came from six sources of breeds (crossbreeds) by using the insemination of mixed sperms, was used to study for the effect of candidate genes (cPRL, cOVR, cOIH and cGnRHR) of the egg performance on the traits recorded through association analysis. Seven new SNPs were found in cOIH and cGnRHR by electronic SNP, PCR-SSCP + sequencing, PCR-RFLP and ACRS-PCR and an insertion/deletion coving 186bp was found in cGnRHR. It is showed that there is significant(p<0.05) associations between the cPRL and the egg production and the gene effect is mainly additive; and there exist significant(p<0.05) associations between cOVR and the egg production, the age of first egg, egg weight, the thickness of eggshell and the percentage of yolk, and the gene effect is mainly dominance and it shows over-dominance on some of the traits. These results validate that cPRL and cOVR have effects on the egg performance and the qualities of egg mentioned before by other researchers. For cOIH, it was found that there is significant (p<0.05) association with egg production, age at first egg and percentage of albumen and there is also significant(p<0.05) association for cGnRHR with egg production. Based on this research, the cPRL and cOVR could be utilized in the breeding of strains for egg for improving the egg performance, and for the cOIH and cGnRHR it need be further verified their effects on the egg performance before using them in the improvement. Suggestions are also put forward for how to utilize these genes in the genetic improvement of chicken.