Study On Growth And Development Of Fast And Slow Feather Of Bashang Long-Tail Chicken Pure Line Group And Identification Of Skin Color Gene

The Bashang long-tailed chicken is a valuable local breed resource in China,and belongs to the egg-meat dual-purpose chicken breed.Due to the invasion and hybridization of foreign breeds,the traits of this breed were seriously degraded,the origin of the chicken was not modernized,and the number of purebred chickens in the population decreased day by day.Therefore,it can not only reveal the growth and development rules of different populations in Bashang Long-tailed chicken,but also provide a real and reliable data reference for the breeding of long tail chicken.Optimizing the population of Bazhang long tail chicken can also add a new choice for the residents’ dietary structure.In this study,the female and male pure line of fast and slow feathering was used as the sample of the long tail chicken of Bashang,the body weight and body size of brood and adult were measured according to different feather velocities and different genders;Egg laying performance of Bashang long tail Chicken with different feathering velocities and different colors.To explore the growth and development law and egg laying performance of the long tail chicken in Bashang with different feather velocities and different feather colors.In this study,it was found the difference in the pure line population of Bashang long-tailed chicken.The results show that: 1.The gene of feathering speed has a significant effect on the body weight and body size of the long-tailed chicken in Bashang（P < 0.05）.2.In the same feather line,the weight of the cock was always higher than that of the hen,and gender had a significant effect on body weight and body size（P < 0.05）.3.The effect of feather color on egg production rate was not significant（P > 0.05）.In three kinds of plumage colors of fast feathering line,egg weight hemp feather > black feather > white feather,but did not reach the significant level（P > 0.05）.4.In different feather colors,fast and slow feathers have different advantages in laying eggs.Yellow skin and yellow shank have become an important trait of domestic chickens because of the increasing preference of most consumer groups for yellow skin of broilers.The formation of shallow skin of a chicken depends on the amount of carotenoid on the skin.The deposition of such carotenoids is related to the enzymes BCMO1 and BCDO2 that can decompose carotenoids in domestic chickens.It was found that three SNPs related to yellow skin of European domestic chicken（chr24:6264085 G < A;chr24:6273428 A < G;chr24: 6287900 G < A）were found in BCDO2 gene.In order to verify the distribution of three SNPs loci in Hebei local breed Bashang long-tailed chicken,In this study,three kinds of shank color were used as the research object.The nucleotide sequences of three SNPs loci and their peripheral fragments were obtained by PCR amplification and Sequencing technology to detect the genetic diversity of the polymorphic loci in the three SNPs and peripheral fragments of the BCDO2 gene.The distribution of genotype alleles and haplotypes of three SNPs and their correlation with skin color were analyzed.The results showed that : 1.the A locus of chr24:6264085 and the B locus of chr:24 6273428 were significantly correlated with the yellow complexion of domestic chickens.The chr24: 6287900 C locus was not correlated with yellow skin color.2.In addition to the three known SNPs loci,the other three SNPs loci were found arounding C locus were 300 loci、400 loci and 511 loci respectively,which may be related to the yellow skin of domestic chickens.3.There are five haplotypes in the sample population,one of them is: H₁（-AGAAGC-）、 H₂（-AGAAAC-）、H₃（-GGAAGC-）、H₄（-GAAAGC-）、H₅（-GAGAAT-）。The frequency of H1 AGAAGC-haplotype is the highest,and it is the dominant genotype of yellow skin color.