| Danzhou chicken is the only local species chicken with small body size and tropical island characteristics in China.It has a long history of breeding.However,due to the lack of industrial development,the population size is small and the breeding is closed relatively.To scientifically protect and systematically select the genetic resources of Danzhou chickens for breeding,240 chickens from 5 places were subjected to genetic diversity detection,genetic diversity analysis and genetic relationship research at 15 microsatellites locus in the study,including Danzhou chicken,Lifeng chicken,Bawang Mountain chicken,Wenchang chicken and Beijing fatty chicken.Through the testing the reproductive performance,quality and nutritional composition of eggs,quality traits and nutritional composition of chicken as well as serum hormones of Danzhou flaxen-feathered chicken and Danzhou black-feathered chicken,the following results were obtained after comparison and analysis on their differences in production performance:1.For the genetic diversity of 5 chicken populations,240 individuals had 143 alleles at 15 microsatellites locus,the average quantity of observed alleles(Na)was9.53 and the average effective allele(Ne)was 3.50.Among the 15 microsatellites locus in Danzhou chicken,MCW0183 was a monomorphic loci.After removing MCW0183,the average quantity of observed alleles(Na)was 5.57 and the average effective alleles(Ne)was 2.89,among which the maximum quantity of alleles detected was at LEI0094 of 3.8788 and the minimum quantity of alleles detected was at ADL0278 of 1.9946.The average polymorphic information content(PIC)of 14 microsatellites locus in Danzhou chicken was 0.58,the observed heterozygosity(Ho)was 0.6261 and the expected heterozygosity(He)was 0.6446,not including MCW0183.2.For genetic relationship of 5 chicken flocks,the genetic similarity between Danzhou chicken and Changjiang Bawang Mountain chicken was 0.8567 and the genetic distance was 0.1547;the genetic similarity to Beijing fatty chicken was0.7340 and the genetic distance was 0.3093;the genetic similarity to Lifeng chicken was 0.8029 and the genetic distance was 0.2196;the genetic similarity to Wenchang chicken was 0.7785 and the genetic distance was 0.2504.According to the results of Nei’s genetic distance and hierachical clustering,the five chicken populations were grouped into three categories: Danzhou chicken and Changjiang Bawang Mountain chicken were one group,Wenchang chicken and Lifeng chicken were one group;3.Beijing fatty chicken was a group alone since their genetic distances with the other four was far,which was larger than the genetic distances between the other populations.4.For the production performance of Danzhou flaxen-feathered chicken and Danzhou black-feathered chicken,the average production of flaxen-feathered chicken was 137 eggs and black-feathered chicken was 117 eggs,while their fertilization rate and hatching rate of fertilized eggs were all above 90%;there were no significant differences in egg weight,egg shape index,eggshell hardness,eggshell thickness or Haugh unit(P>0.05);the content of egg whites in black-feathered chicken was higher than that in flaxen-feathered chicken(P<0.01);egg yolk ratio of flaxen-feathered chicken was higher than that in black-feathered chicken(P<0.05);there was no significant difference in the content of crude ash,crude protein,crude fat,calcium,phosphorus,cholesterol or hormones,such as growth hormone leptin,insulin,etc.(P>0.05);the content of egg white lecithin in flaxen-feathered chicken was higher than that in black-feathered chicken(P<0.05);the content of estradiol and progesterone in flaxen-feathered chicken was higher than that in black-feathered chicken(P<0.01).The PH value of pectoral muscles and leg muscles was between 5.5and 6.5,and the tenderness of the leg muscles was better than that of the pectoral muscles,however,the cooked meat rate of the leg muscles was slightly lower than that of the pectoral muscles;compared with flaxen-feathered chicken,black feathered chicken had a higher crude protein content and less crude fat content(P>0.05);there was no significant difference in cholesterol or leptin content between the two chicken of 1 week and 6 months age(P>0.05);the content of lecithin and growth hormone in black feathered chicken was significantly higher than that in flaxen-feathered chicken of 1 week age(P<0.01);the content of estradiol in black feathered chicken was significantly higher than that in flaxen feathered chicken(P<0.05);the content of progesterone and insulin in black-feathered chicken were significantly higher than that in flaxen-featured chicken(P<0.01). |
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