Egg Laying Performance And Regulation Of Reproductive Hormones In Danzhou Chickens

Danzhou Chicken,which also called Danzhou small Chicken,is a valuable local breed resource in Hainan Province.In this study,a comprehensive determination and correlation analysis of the egg laying performance of Danzhou chicken was conducted to reveal the changes of its egg laying performance and its laying rate,to provide the basis for the next step of breeding work.Enzyme-linked immuno sorbent assay(ELISA)was performed to determine the main reproductive hormone concentrations in different stages of the chicken production,to reveal the changing rules of the secretion level of reproductive hormones and the regulatory rules of the reproductive hormones of Danzhou Chicken on laying eggs.Exogenous FSH and LH were injected into Danzhou chicken to determine their effect on reproductive hormone secretion,to explore the regulation mechanism of reproductive hormone of Danzhou Chicken.Meanwhile,Danzhou chicken FSH beta gene was sequenced for the detection of the single nucleotide polymorphisms(SNPS),revealing FSH beta gene mutation in Danzhou chicken situation.The results provide a scientific basis for the future population protection and exploitation of Danzhou chickens.The main results were as follows:1.After two generations of breeding,the Egg laying performance of Danzhou chicken had been improved.The age and weight of the first egg of the second generation groups is 123.67±3.51d and 881.37±86.78g,which was increased by 3.61%and 2.67%respectively;the egg production and the egg wight at 300d is 28.02±2.13g and 37.12±2.3g,which was basically consistent with first generation.the weight in 40 weeks and egg production in 40 weeks was 979.36± 147.01g and 70.08± 1.89,which was increased by 3.43%and 6.87%(P<0.05)respectively.Correlation analysis showed that the egg production index of Danzhou chicken was extremely significantly correlated with the age of open birth(P<0.01),which was significantly correlated with the birth weight(P<0.05).2.The changes of FSH and LH in the blood of Danzhou chicken were basically consistent with the changes in egg production rate.The concentration of FSH and LH and P in the production period was significantly higher than that in the early stage of production(P<0.05).The concentration of FSH and LH in the blood was significantly higher than that in other periods(P<0.05).The concentration of PRL,E2 and P in the blood in the later stage of egg production was significantly higher than that in the peak of egg production(P<0.05).The secretion of FSH and LH decreased significantly during the peak period of egg production(P<0.05).3.The increase of FSH or LH concentration in Danzhou chicken blood could significantly reduce the concentration of PRL in blood(P<0.05),while increasing the concentration of E2 and P in different degrees.The concentration of FSH and LH in the blood of Danzhou chickens can significantly increase the concentration of E2 and P in the blood(P<0.01),and increase the concentration of PRL in the blood(P<0.05).4.25 SNPs in FSH of Danzhou chicken were found,wherein 5 SNPs in introns and 20 SNPs in exons.Two SNPs locus in FSH gene coding regions,which were missense mutations.