Three-yellow Chickens Research Articles

Effects of partial replacement of soybean meal with hemp seed (Cannabis sativa L.) cake on the growth and meat quality in female three-yellow chickens

Effects of partial replacement of soybean meal with hemp seed (Cannabis sativa L.) cake on the growth and meat quality in female three-yellow chickens

The American cockroach (Periplaneta americana) residue could partially replace the dietary puffed soybean meal in the Three-yellow chickens

Periplaneta americana residue is a byproduct of using Periplaneta americana in pharmaceutical research and development for extracting active ingredients. Three hundred Three-yellow chickens were selected for the experiment and randomly divided into 6 groups (5 replications per group, 10 chickens per replicate): the control group (group A) was fed a basal ration, and the experimental groups (groups B, C, D, E, and F) were fed experimental diets in which P. americana residue replaced puffed soybean meal at proportions of 20, 40, 60, 80, and 100%, respectively, for a period of 42 d. The aim was to assess the impact of different levels of P. americana residue on the growth, survival, intestinal morphology, digestive enzyme activity, intestinal flora, and intestinal transcriptional responses of Three-yellow chickens. The results indicated that the increase in P. americana residue levels had a linear and quadratic impact on the average daily gain (ADG) and feed conversion ratio (FCR), respectively. The ADG was notably greater in the 40% group than in the 100% group, while the FCR was significantly lower in the 20% and 40% groups than in the 100% group (P < 0.05). Protease, lipase, and amylase activities exhibited a quadratic increase with increasing concentrations of P. americana residue (P < 0.05). Protease and lipase activities were notably greater in the 20% and 40% groups than in the 0% group (control group), amylase activity was significantly greater in the 40% group than in the 0% group (control group) (P < 0.05). Duodenal crypt depth (CD) decreased quadratically with increasing P. americana residue (P < 0.05). The duodenal villus height/crypt depth ratio (V/C) was significantly lower in the 100% group than in the 60% group (P < 0.05). The intestinal villus height (VH) increased quadratically with increasing levels of P. americana residue. The VH in the 60% group was significantly greater than that in the 0% (control group), 20, 80, and 100% groups (P < 0.05). The Chao and Ace indices demonstrated linear and quadratic increases with increasing levels of P. americana residue, while the Pd index showed a quadratic increase with increasing levels of P. americana residue (P < 0.05). The relative abundance profile of Lactobacillus exhibited a linear and quadratic decrease with increasing levels of P. americana residue, with the 100% group showing a significantly lower abundance than the 0% (control group) and 40% groups (P < 0.05). The transcriptome results showed that P. americana residue could enhance the digestive system by promoting vitamin, fat, carbohydrate digestion and absorption, cholesterol metabolism, etc. In conclusion, P. americana residue can replace puffed soybean meal without negatively affecting the growth performance of three-yellow chickens. The low and medium groups had positive effects on the growth performance, digestive enzyme activity, intestinal morphology, intestinal flora, and substance digestion and absorption of three-yellow chickens. The recommended replacement of P. americana residue for puffed soybean meal in the diets of three-yellow chickens ranged from 20% to 60%.

The coinfection of ALVs causes severe pathogenicity in Three-Yellow chickens

The coinfection of ALVs (ALV-J plus ALV-A or/and ALV-B) has played an important role in the incidence of tumors recently found in China in local breeds of yellow chickens. The study aims to obtain a better knowledge of the function and relevance of ALV coinfection in the clinical disease of avian leukosis, as well as its unique effect on the pathogenicity in Three-yellow chickens. One-day-old Three-yellow chicks (one day old) were infected with ALV-A, ALV-B, and ALV-J mono-infections, as well as ALV-A + J, ALV-B + J, and ALV-A + B + J coinfections, via intraperitoneal injection, and the chicks were then grown in isolators until they were 15 weeks old. The parameters, including the suppression of body weight gain, immune organ weight, viremia, histopathological changes and tumor incidence, were observed and compared with those of the uninfected control birds. The results demonstrated that coinfection with ALVs could induce more serious suppression of body weight gain (P < 0.05), damage to immune organs (P < 0.05) and higher tumor incidences than monoinfection, with triple infection producing the highest pathogenicity. The emergence of visible tumors and viremia occurred faster in the coinfected birds than in the monoinfected birds. These findings demonstrated that ALV coinfection resulted in considerably severe pathogenic and immunosuppressive consequences.

Potential Mechanism and Effects of Different Selenium Sources and Different Effective Microorganism Supplementation Levels on Growth Performance, Meat Quality, and Muscle Fiber Characteristics of Three-Yellow Chickens.

A trial was conducted to investigate the effects of different Se sources, including sodium selenite (S-Se) and selenium yeast (Y-Se) and different effective microorganism (EM) addition levels on growth performance, meat quality, and muscle fiber characteristics of three-yellow chickens and its potential mechanism. A total of 400 birds were randomly distributed into 4 groups (S-Se, S-Se + EM, Y-Se, and Y-Se + EM groups) consisting of a 2 × 2 factorial arrangement. The main factors were the source of Se (ISe = inorganic Se: 0.2 mg/kg S-Se; OSe = organic Se: 0.2 mg/kg Y-Se) and the level of EM (HEMB = high EM: 0.5% EM; ZEMB = low EM: 0% EM). Each treatment had 5 replicates and each replicate consisted of 20 broiler chickens. The trial lasted for 70 days. The results showed that, in breast muscle, the broiler chickens fed OSe source decreased the pH24h, drip loss, shear force, perimeter, cross-sectional area, and diameter, but increased the and density compared with the broiler chickens fed ISe source (p < 0.05); broiler chickens supplied with HEMB level decreased the cross-sectional area and diameter, but increased the pH24h, and density compared with the broiler chickens supplied with ZEMB level (p < 0.05). In thigh muscle, OSe source and HEMB level also could improve the meat quality and change muscle fiber characteristics of broiler chickens (p < 0.05). Meat quality was correlated with the muscle fiber characteristics (p < 0.05). OSe source and HEMB level could regulate the expression levels of muscle fiber-relative genes in the breast and thigh muscles (p < 0.05). In conclusion, OSe source and HEMB level could improve the meat quality of the breast and thigh muscles of three-yellow chickens by changing the muscle fiber characteristics, and they changed the muscle fiber characteristics by regulating the expression levels of muscle fiber-relative genes.

The emerging naturally reassortant strain of IBDV (genotype A2dB3) having segment A from Chinese novel variant strain and segment B from HLJ 0504-like very virulent strain showed enhanced pathogenicity to three-yellow chickens.

Novel variant infectious bursal disease virus (nvIBDV) is an emerging pathotype that can cause sub-clinical disease with severe, prolonged immunosuppression in young chickens. At present, two major pathotypes, including vvIBDV and nvIBDV, are prevailing in China. In this study, we propose that the nvIBDV is a new genotype (A2dB1b) and also first isolated and characterized a nvIBDV reassortant strain YL160304 (A2dB3) with segments A and B derived, respectively, from the nvIBDV and the HLJ-0504-like vvIBDV from yellow chickens in southern China. The YL160304 causes more extensive cytotropism and can infect specific-pathogen-free chicken embryos with severe subcutaneous hemorrhage. The pathogenicity of YL160304 to 4-week-old three-yellow chickens was determined and compared with those of the nvIBDV QZ191002 and the HLJ-0504-like vvIBDV NN1172. Weight gain was significantly reduced in all the challenged birds. No clinical signs and associated mortality were observed in the birds challenged with QZ191002, while the mortalities in the birds challenged with NN1172 and YL160304 were 30% (3/10) and 10% (1/10), respectively. At 7 days postchallenge, the bursa was severely damaged and the percentage of peripheral blood B lymphocyte (PBBL) decreased significantly in all the challenged birds and the quantity of the viral RNA detected in the bursa was in accordance with the results of the histomorphometry and the depletion of PBBL. This study not only confirmed the emerging epidemic of the novel variant and its reassortant strains, but also discovered that the naturally reassortant nvIBDV strain with the segment B of HLJ 0504-like vvIBDV can significantly enhance the pathogenicity to chickens.

Protective Effects of α-Lipoic Acid and Chlorogenic Acid on Cadmium-Induced Liver Injury in Three-Yellow Chickens.

Simple SummaryCadmium (Cd) exerts pernicious influences on global health. We evaluated the protective effects of α-lipoic acid (α-LA) or chlorogenic acid (CGA) and their combination on counteracting Cd toxicity in vivo in three-yellow chickens. Administration of Cd (50 mg/L) alone lowered the production performance and resulted in biochemical, histologic and enzyme changes within the liver consistent with hepatic injury induced by oxidative stress and apoptosis of hepatocytes. However, the above variations of the Cd group were partially or fully reversed by administration of either α-LA or CGA; their combination showed an even better effect in attenuating Cd-induced hepatotoxicity. This study provided a practical and feasible approach to rescuing Cd intoxication in animal production.Cadmium (Cd) is a type of noxious heavy metal that is distributed widely. It can severely injure the hepatocytes and cause liver dysfunction by inducing oxidative stress and mitochondrial damage. We evaluated the protective effects of α-lipoic acid (α-LA) or chlorogenic acid (CGA) and their combination on counteracting cadmium toxicity in vivo in three-yellow chickens. For three months, CdCl2 (50 mg/L) was administrated through their drinking water, α-LA (400 mg/kg) was added to feed and CGA (45 mg/kg) was employed by gavage. The administration of Cd led to variations in growth performance, biochemical markers (of the liver, kidney and heart), hematological parameters, liver histopathology (which suggested hepatic injury) and ultrastructure of hepatocytes. Some antioxidant enzymes and oxidative stress parameters showed significant differences in the Cd-exposure group when compared with the control group. The groups treated with Cd and administrated α-LA or CGA showed significant amelioration with inhibited mitochondrial pathway-induced apoptosis. Combining both drugs was the most effective in reducing Cd toxicity in the liver. In summary, the results demonstrated that α-LA and CGA may be beneficial in alleviating oxidative stress induced by oxygen free radicals and tissue injury resulting from Cd-triggered hepatotoxicity.

ALV-J-contaminated commercial live vaccines induced pathogenicity in Three-Yellow chickens: one of the transmission routes of ALV-J to commercial chickens

One avian leukosis virus of subgroup J (ALV-J) strain GX14YYA1 was isolated from a commercial bivalent Newcastle disease (ND)–infectious bronchitis (IB) vaccine in our previous study. To evaluate the pathogenicity of the ALV-J-contaminated vaccine on commercial chickens, day-old Three-Yellow chicks in group I were vaccinated with ALV-J-contaminated bivalent ND-IB live vaccine by intranasal and eye drop at 1-day-old for the primary vaccination and at 7-day-old for the secondary vaccination. Groups II and III were kept as the normal vaccination group with the noncontaminated ND-IB vaccine and blank control groups, respectively. The birds of different groups were maintained separately in isolators for 175 d. The first viremia was detected at 4 wk of age and 20% (2/10) of the birds maintained viremia during 11 to 25 wk of age. At the same time, the birds in group I experienced a significant suppression of body weight gain when compared with those of groups II and III (P < 0.05). In addition, the birds in group I showed obvious ALV-J hemangioma-type anatomical lesions in the liver and tumors were observed in the abdominal cavity. The results demonstrated that the ALV-J contaminated commercial live vaccines can induce pathogenicity in commercial Three-Yellow chickens and indicate that ALV-J-contaminated commercial live vaccines could be one of the transmission routes of ALV-J to commercial chickens.

The Full Region of N-Terminal in Polymerase of IBDV Plays an Important Role in Viral Replication and Pathogenicity: Either Partial Region or Single Amino Acid V4I Substitution Does Not Completely Lead to the Virus Attenuation to Three-Yellow Chickens.

Infectious Bursal Disease Virus (IBDV) has haunted the poultry industry with severe, prolonged immunosuppression of chickens when infected at an early age and can easily lead to other secondary infections. Understanding the pathogenic mechanisms could lead to effective prevention and control of Infectious Bursal Disease (IBD). Evidence suggests that the N-terminal domain of polymerase in segment B plays an important role, but it is not clear which part or residual is crucial for the pathogenicity. Using a reverse genetics technique, a molecular clone (rNN1172) of the parental vvIBDV strain NN1172 was generated, and its pathogenicity was found to be the same as the parental virus. Then, three recombinant chimeric viruses were rescued based on the rNN1172 and substituted with the counterparts in the N-terminal domain of the attenuated vaccine strain B87: the rNN1172-B87VP1a (substituting the full region of the 1–167 aa residuals), the rNN1172-B87VP1a∆4 (substituting the region of the 5–167 aa residuals), and the rNN1172-VP1∆4 (one single aa residual substitution V4I), to better explore the role of the N-terminal domain of polymerase on the viral pathogenicity. Interestingly, all these substitutions played different roles in the viral pathogenicity: the mortality of the rNN1172-B87VP1a-challenged chickens was significantly reduced from 30% to 0%. No obvious lesion was found in the histopathological examination, and the lowest viral genome copy number was also detected in the bursa when compared to the parental and two other recombinant viruses. The mortalities caused by rNN1172-B87VP1a∆4 and rNN1172-B87VP1∆4, respectively, were all reduced to 10% and had a delayed onset of death. Our results also revealed that the pathogenicity of the IBDV was consistent with the viral replication efficiency in vivo (bursae). This study demonstrated that the full region of the N-terminal of polymerase plays an important role in viral replication and pathogenicity, but the substitutions of its partial region or a single residual do not completely lead to the virus attenuation to Three-Yellow chickens, although that significantly reduces its pathogenicity.

An outbreak in three-yellow chickens with clinical tumors of high mortality caused by the coinfection of reticuloendotheliosis virus and Marek’s disease virus: a speculated reticuloendotheliosis virus contamination plays an important role in the case

Both reticuloendotheliosis and Marek's disease are neoplastic diseases of chickens caused by reticuloendotheliosis virus (REV) and Marek's disease virus (MDV), respectively. The infection of REV or MDV may lead to clinical tumors and also result in immunosuppression and easily allow secondary infection by other pathogens. Here, we investigated a breeder flock of three-yellow chickens in southern China that had been vaccinated with CVI988/Rispens at hatching and had experienced depression, weakness, reduction in weight gain, and an increased death rate after 120 d of age. The morbidity and mortality were 20% and 10%, respectively, at 140 d of age when this infection was diagnosed. The necropsy of the birds revealed significant tumor-like lesions in the heart, liver, spleen, and ceca. Peripheral blood lymphocytes and tumor-like tissues were sampled for PCR detection and for histopathological observation, for virus isolation and the subsequent immunofluorescent assay on the cell cultures and for gene sequencing of the isolated viruses. A REV isolate GX18NNR1 and a MDV isolate GX18NNM5 were both recovered from the sampled bird. Further phylogenetic analysis based on the env gene of REV and the meq gene of MDV demonstrated that GX18NNR1 was closely related to the reference REV strain MD-2, which was isolated from a contaminated commercial turkey herpesvirus vaccine. In addition, the GX18NNM5 was found to belong to the Chinese very virulent MDV strains' cluster. The coinfection of REV and MDV may contribute to tumor outbreaks with high morbidity and mortality in three-yellow chicken flocks.

Vertical transmission of ALV from ALV-J positive parents caused severe immunosuppression and significantly reduced marek’s disease vaccine efficacy in three-yellow chickens

In order to evaluate the influence of the vertical transmission of avian leukosis virus (ALV) from J subgroup (ALV-J) positive parents on the vaccine efficacy of Marek’s disease virus (MDV), ALV-J positive male breeders × female breeders of Three-yellow chickens and the ALV negative male breeder × the negative female breeders were used respectively for crossbreeding to produce eggs and the hatching offspring. The commercial CVI988/Rispens vaccine was used to vaccinate the crossbred offspring at 1-day-old. At 7-days-old, the birds were inoculated with the inactivated oil-emulsion vaccines (OEVs) AIV-H5 monovalent and NDV + AIV-H9 bivalent, respectively. Then the birds were challenged with a Chinese very virulent (vv) MDV field strain GXY2 at 14-day-old. The results showed that the viral load of the challenged GXY2 in the offspring from the ALV-J positive breeders was significantly higher than that from the ALV-negative breeders’ (P < 0.05), and the mortality and tumor incidence of offspring from the ALV-J positive breeders were higher than those of the ALV-negative breeders. Also the offspring of the ALV-J positive breeders exhibited a significant negative effect on the development of the immune organs (P < 0.05) and lower antibody responses to the vaccinations with the commercial OEVs (P<0.05). The MD vaccine protective index in the offspring from the ALV-J positive breeders was lower than that from the ALV-negative breeders. The results of the study demonstrated that the vertical transmission of ALV from the ALV-J positive parents caused severe immunosuppression and significantly reduced the Marek’s disease vaccine efficacy in Three-yellow chickens.

A novel recombinant avian leukosis virus isolated from gamecocks induced pathogenicity in Three-Yellow chickens: a potential infection source of avian leukosis virus to the commercial chickens

ABSTRACTOne natural recombinant avian leukosis virus (ALV) strain GX14DJ3–18 was isolated from a native gamecock by DF-1 cell culture and identified with Polymerase Chain Reaction (PCR), immunofluorescence assay and the viral genome's nucleotide sequencing. This strain was revealed as a novel recombinant virus with nucleotide sequence similarities of 95.4% Long Terminal Repeated (LTR), 95.8% 5′, UTR, 97.9% gag, and 92.9% 3′untranslated regions (UTR) in ALV-J. Also we found sequence similarities of 99.3% pol and 99.0% gp37 in ALV-E, and 89.9% gp85 in ALV-A. The simulated congenital infection with GX14DJ3–18 in Three-Yellow chickens exhibited a significant negative effect on the development of immune organs (P < 0.05). Also, lower antibody responses were found to vaccinations with the commercial vaccines of Newcastle disease virus and with subtypes H5 and H9 of avian influenza virus (P < 0.05). The incidence of tumor or tumor-like lesions in the challenged birds was 14.28% (5/35), while none were observed in the un-challenged control group (0/35). These results suggested that GX14DJ3–18 is a novel recombinant ALV that can induce pathogenicity in the commercial Three-Yellow chickens. We speculated that cross-provincial sales of gamecocks in which ALVs have not been eradicated thoroughly might be a potential route for the transmission of ALVs to commercial chickens.

Antigenicity characterization of four representative natural reassortment IBDVs isolated from commercial three-yellow chickens from Southern China reveals different subtypes co-prevalent in the field

The antigenic relationships between the natural reassortment field strains of infectious bursal disease virus (IBDV), and between the field strains and the vaccine strains are poorly understood. In the present study, the antigenicity of four representative natural reassortment IBDV isolates designated JS7, GD10111, NN1005 and NN1172 from southern China during the years 2005–2011 and their antigenic relationship with the most commonly used vaccine strain B87 were investigated in vivo. For this purpose, cross-challenge studies were performed on 28-day-old birds, which were 2 weeks post-vaccination by oil-emulsion vaccines (OEVs) prepared from the four field viruses and B87, respectively. The protection related values (PRV) were evaluated based on the protection rate measured by clinical signs and mortality, bursa/body weight (B/BW) ratio and the viral load in the bursal samples at 3 and 7 days post challenge. As a result, the PRV showed that the isolates NN1172 and GD10111 belonged to the same antigenic subtype, while the isolates NN1005 and JS7 belong to another subtype. The vaccine strain B87 was grouped with the isolates NN1005 and JS7 but actually belongs to another small subgroup and provided only 60–80% protection against the challenge of the four field strains. The results demonstrated that different antigenic subtypes co-existed among the field natural reassortment IBDV strains and the commonly used vaccine strain B87 was antigenically different from the prevalent IBDVs in southern China.

Hydropericardium syndrome outbreak caused by fowl adenovirus serotype 4 in China in 2015.

There have been many outbreaks of hydropericardium syndrome (HPS), which is characterized by pericardial effusion and hepatitis, in Chinese chicken farms since June 2015. HPS was mainly found in miscellaneous meat-type chickens, Ma chickens, layer chicks and Three-yellow chickens, while it was occasionally found in white broilers. To determine the specific causative pathogen and pathogenicity of HPS in chickens, we collected 25 suspected cases and performed clinical pathology and aetiology analyses. The results showed that the 25 cases exhibited multifocal hepatitis with intra-nuclear inclusion bodies and 70 nm-latticed viral particles in the cell nuclei. All samples were positive for fowl adenovirus (FAdV), and sequencing results showed that the hexon gene shared the highest nucleotide similarities with the hexon gene of group 1 serotype 4 (FAdV-4). FAdV-4 was highly pathogenic to embryos and specific pathogen-free chickens, causing 100 and 70 % mortality rates, respectively. Thus, FAdV-4 is associated with HPS outbreaks in China.

Role of naturally occurring genome segment reassortment in the pathogenicity of IBDV field isolates in Three-Yellow chickens

ABSTRACTReassortment among genome segments of infectious bursal disease virus (IBDV) field isolates was reported frequently worldwide, however the pathogenicity of the reassortant field IBDV is poorly understood. In this paper, a pathogenicity study on four representative IBDV field strains isolated from Southern China between 2005 and 2011 was conducted. Twenty-eight-day-old Three-Yellow chickens were divided into four groups and were inoculated intraocularly with one of the four field IBDV strains, namely NN1172, NN1005, GD10111 and JS7, respectively. The mortality and relative weight of bursa and thymus were subsequently determined in the acute phase of infection. In addition, B cells, T cells (CD4+ and CD8+) and virus were quantified in the bursa of Fabricius and thymus, respectively, by flow cytometry and real-time reverse transcription-polymerase chain reaction. The results showed that isolate NN1172, of which parts of segment A and B encoding the hypervariable (v) region of viral protein (VP2) and VP1, respectively, derived from vvIBDV strains, showed the most severe pathogenicity, and caused the most severe bursal B cell depletion as well as CD4+ and CD8+ T cell infiltration in the bursa of Fabricius. However, the virus induced the strongest decrease in CD4+ and CD8+ T cells in the thymus and exhibited the most efficient viral replication in the target organs. Isolate NN1005, whose vVP2 derived from vvIBDV and VP1 from unidentified origin, exhibited relatively lower pathogenicity compared to NN1172. The other two isolates, JS7 and GD10111, of which the vVP2 derived from vvIBDV and intermediate IBDV, and VP1 from 002–73 and attenuated IBDV, respectively, showed the lowest level of virulence. Our results suggest that various IBDV field isolates with different natural segment reassortments exhibit differential pathogenicity after infection of commercial Three-Yellow chickens.

Association of H-FABP gene polymorphisms with intramuscular fat content in Three-yellow chickens and Hetian-black chickens.

BackgroundTo explore the relationship between the heart-type fatty acid binding protein (H-FABP) gene and intramuscular fat (IMF), a polymorphism of the second exon of the H-FABP gene was investigated in 60 Three-yellow chickens (TYCs) and 60 Hetian-black chickens (HTBCs).ResultsThe IMF contents of the cardiac, chest and leg muscles in HTBC were increased compared with TYC. Both TYC and HTBC populations exhibited Hardy-Weinberg Equilibrium (HWE) according to the χ2 test. Three variations of the two birds were detected, namely, G939A, G982A and C1014T. HTBCs with the TT genotypes exhibit increased IMF content in the chest muscles compared with the TC genotype. Thus, the G982A site could be considered a genetic marker for selecting increased IMF content in the chest muscles of HTBC. The correlation coefficients revealed that H-FABP mRNA expression was negatively correlated with the IMF content in the cardiac, chest and leg muscles of HTBC and in the cardiac and chest muscles of TYC. The relative mRNA expression of H-FABP was reduced in the cardiac and leg muscles of HTBC compared with TYC, but this difference was not observed at the protein level, as assessed by Western blot analysis.ConclusionsThese findings offer essential data that can be useful in the breeding program of HTBC and future research exploring the role of H-FABP in IMF deposition and regulation in chickens.

Genome-wide methylation changes are associated with muscle fiber density and drip loss in male three-yellow chickens

In eukaryotes, DNA methylation is an important epigenetic modification involved in gene expression regulation. Meat quality traits are complicated traits that are controlled by many genes. Changes in the methylation levels of certain genes controlling meat quality traits will inevitably affect their expression levels, thereby affecting meat quality. The objectives of this study were to investigate the differences in the DNA methylation level in pectoral muscle tissues using fluorescent-labeled methylation sensitive amplified polymorphism and their relationships with meat quality traits in three-yellow chickens. The results showed that the differences in the DNA methylation level had a highly significant effect on muscle fiber density and drip loss (P<0.01). However, no significant correlations were found between the DNA methylation levels and the other investigated traits (P>0.05).

Microsatellite DNA Typing for Assessment of Genetic Variability in Guangxi Three-yellow Chickens

Microsatellite DNA Typing for Assessment of Genetic Variability in Guangxi Three-yellow Chickens

Assessment of Population Structure and Genetic Diversity of 15 Chinese Indigenous Chicken Breeds Using Microsatellite Markers

The genetic structure and diversity of 15 Chinese indigenous chicken breeds was investigated using 29 microsatellite markers. The total number of birds examined was 542, on average 36 birds per breed. A total of 277 alleles (mean number 9.55 alleles per locus, ranging from 2 to 25) was observed. All populations showed high levels of heterozygosity with the lowest estimate of 0.440 for the Gushi chickens, and the highest one of 0.644 observed for Wannan Three-yellow chickens. The global heterozygote deficit across all populations (FIT) amounted to 0.180 (p<0.001). About 16% of the total genetic variability originated from differences between breeds, with all loci contributing significantly to this differentiation. An unrooted consensus tree was constructed using the Neighbour-Joining method and pair-wise distances based on marker estimated kinships. Two main groups were found. The heavy-body type populations grouped together in one cluster while the light-body type populations formed the second cluster. The STRUCTURE software was used to assess genetic clustering of these chicken breeds. Similar to the phylogenetic analysis, the heavy-body type and light-body type populations separated first. Clustering analysis provided an accurate representation of the current genetic relations among the breeds. Remarkably similar breed rankings were obtained with all methods.