S Weigend

Publications (37)59.13 Total impact

• Article: Erratum to "Diversity and origin of South African chickens" (Poult. Sci. 90(10):2189-2194).

  B J Mtileni, F C Muchadeyi, A Maiwashe, M Chimonyo, E Groeneveld, S Weigend, K Dzama
  Poultry Science 05/2012; 91(5):1277. · 1.73 Impact Factor
• Source

  Available from: Johannes A Lenstra

  Article: Molecular tools and analytical approaches for the characterization of farm animal genetic diversity.

  J A Lenstra, L F Groeneveld, H Eding, J Kantanen, J L Williams, P Taberlet, E L Nicolazzi, J Sölkner, H Simianer, E Ciani, J F Garcia, M W Bruford, P Ajmone-Marsan, S Weigend
  [show abstract] [hide abstract]
  ABSTRACT: Genetic studies of livestock populations focus on questions of domestication, within- and among-breed diversity, breed history and adaptive variation. In this review, we describe the use of different molecular markers and methods for data analysis used to address these questions. There is a clear trend towards the use of single nucleotide polymorphisms and whole-genome sequence information, the application of Bayesian or Approximate Bayesian analysis and the use of adaptive next to neutral diversity to support decisions on conservation.
  Animal Genetics 01/2012; 43(5):483-502. · 2.40 Impact Factor
• Article: Diversity and origin of South African chickens.

  B J Mtileni, F C Muchadeyi, A Maiwashe, M Chimonyo, E Groeneveld, S Weigend, K Dzama
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  ABSTRACT: The objectives of this study were to analyze the genetic diversity and structure of South African conserved and field chicken populations and to investigate the maternal lineages of these chicken populations. Four South African conserved chicken populations (n = 89), namely, Venda (VD_C), Ovambo, Naked Neck, and Potchefstroom Koekoek from the Animal Production Institute of the Agricultural Research Council, and 2 field populations, the Venda and Ovambo (OV_F), from which the Ovambo and the Venda conservation flocks were assumed to have been sampled, were genotyped for 460 bp of the mitochondrial DNA (mtDNA) D-loop sequence. Haplotypes of these chickens were aligned to 7 Japanese and 9 Chinese and Eurasian chicken mtDNA D-loop sequences taken from GenBank and reflecting populations from presumed centers of domestication. Sequence analysis revealed 48 polymorphic sites that defined 13 haplotypes in the South African chicken populations. All 6 South African conserved and field chicken populations observed were found to be polymorphic, with the number of haplotypes ranging from 3 for VD_C to 8 for OV_F. The lowest haplotype diversity, 0.54 ± 0.08, was observed in VD_C chickens, whereas the highest value, 0.88 ± 0.05, was observed in OV_F chickens. Genetic diversity between the 4 South African conserved and 2 field chicken populations constituted 12.34% of the total genetic variation, whereas within-population diversity constituted 87.66% of the total variation. The median network analysis of the mtDNA D-loop haplotypes observed in the South African conserved and field populations and the reference set resulted in 5 main clades. All 6 South African chickens were equally represented in the major clade, E, which is presumed to be of Indian subcontinent maternal origin and may have its roots in Southeast Asia. The results showed multiple maternal lineages of South African chickens. Conservation flocks and field chicken populations shared the major haplotypes A, D and E, which were presumed to be of Chinese, Southeast Asian, and Indian subcontinental origin.
  Poultry Science 10/2011; 90(10):2189-94. · 1.73 Impact Factor
• Article: Conservation priorities and optimum allocation of conservation funds for Vietnamese local chicken breeds.

  N T K Cuc, S Weigend, H V Tieu, H Simianer
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  ABSTRACT: The objectives of this study were to estimate conservation potential of Vietnamese local breeds and to investigate optimal allocation of conservation funds to maximize genetic diversity conserved between these breeds. Twenty-nine microsatellites were genotyped in 353 individuals from nine Vietnamese local chicken breeds and two chicken breeds of Chinese origin. The Vietnamese chicken breeds were sampled from the northern and southern parts of Vietnam while the two Chinese breeds have been kept as conservation flocks at the National Institute of Animal Sciences, Hanoi. The Weitzman approach was used to assess alternative strategies for conserving genetic diversity between breeds. Three different models, which reflect the range of possible functions in typical conservation situations, were applied. An average extinction probability of 48.5% was estimated for all Vietnamese chicken breeds. The highest conservation potential was found in the Te, Dong Tao and Ac chicken breeds, whereas the lowest corresponding values were observed in the Ri and Mia chicken breeds. The conservation funds were mainly allocated to the same three breeds (Te, Dong Tao and Ac) under all three models. This study suggests that conservation potential of the Vietnamese chicken breeds varies considerably. Population priorities for allocation of conservation funds in this study do not depend on the cost model used. The three breeds (Te, Dong Tao and Ac) with the highest conservation potential should be the prime candidates to be allocated conservation funds if the conservation budgets are limited.
  Journal of Animal Breeding and Genetics 08/2011; 128(4):284-94. · 1.46 Impact Factor
• Source

  Available from: uni-goettingen.de

  Article: Conservation priorities and optimum allocation of conservation funds for Vietnamese local chicken breeds

  N.T.K. Cuc, S. Weigend, H.V. Tieu, H. Simianer
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  ABSTRACT: The objectives of this study were to estimate conservation potential of Vietnamese local breeds and to investigate optimal allocation of conservation funds to maximize genetic diversity conserved between these breeds. Twenty-nine microsatellites were genotyped in 353 individuals from nine Vietnamese local chicken breeds and two chicken breeds of Chinese origin. The Vietnamese chicken breeds were sampled from the northern and southern parts of Vietnam while the two Chinese breeds have been kept as conservation flocks at the National Institute of Animal Sciences, Hanoi. The Weitzman approach was used to assess alternative strategies for conserving genetic diversity between breeds. Three different models, which reflect the range of possible functions in typical conservation situations, were applied. An average extinction probability of 48.5% was estimated for all Vietnamese chicken breeds. The highest conservation potential was found in the Te, Dong Tao and Ac chicken breeds, whereas the lowest corresponding values were observed in the Ri and Mia chicken breeds. The conservation funds were mainly allocated to the same three breeds (Te, Dong Tao and Ac) under all three models. This study suggests that conservation potential of the Vietnamese chicken breeds varies considerably. Population priorities for allocation of conservation funds in this study do not depend on the cost model used. The three breeds (Te, Dong Tao and Ac) with the highest conservation potential should be the prime candidates to be allocated conservation funds if the conservation budgets are limited.
  Journal of Animal Breeding and Genetics 07/2011; 128(4):284 - 294. · 1.46 Impact Factor
• Article: Genetic diversity and conservation of South African indigenous chicken populations.

  B J Mtileni, F C Muchadeyi, A Maiwashe, E Groeneveld, L F Groeneveld, K Dzama, S Weigend
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  ABSTRACT: In this study, we compare the level and distribution of genetic variation between South African conserved and village chicken populations using microsatellite markers. In addition, diversity in South African chickens was compared to that of a reference data set consisting of other African and purebred commercial lines. Three chicken populations Venda, Ovambo and Eastern Cape and four conserved flocks of the Venda, Ovambo, Naked Neck and Potchefstroom Koekoek from the Poultry Breeding Resource Unit of the Agricultural Research Council were genotyped at 29 autosomal microsatellite loci. All markers were polymorphic. Village chicken populations were more diverse than conservation flocks. structure software was used to cluster individuals to a predefined number of 2 ≤ K ≤ 6 clusters. The most probable clustering was found at K = 5 (95% identical runs). At this level of differentiation, the four conservation flocks separated as four independent clusters, while the three village chicken populations together formed another cluster. Thus, cluster analysis indicated a clear subdivision of each of the conservation flocks that were different from the three village chicken populations. The contribution of each South African chicken populations to the total diversity of the chickens studied was determined by calculating the optimal core set contributions based on Marker estimated kinship. Safe set analysis was carried out using bootstrapped kinship values calculated to relate the added genetic diversity of seven South African chicken populations to a set of reference populations consisting of other African and purebred commercial broiler and layer chickens. In both core set and the safe set analyses, village chicken populations scored slightly higher to the reference set compared to conservation flocks. Overall, the present study demonstrated that the conservation flocks of South African chickens displayed considerable genetic variability that is different from that of the assumed founder populations (village chickens).
  Journal of Animal Breeding and Genetics 06/2011; 128(3):209-18. · 1.46 Impact Factor
• Source

  Available from: Herwin Eding

  Article: Assessing genetic diversity of Vietnamese local chicken breeds using microsatellites.

  N T K Cuc, H Simianer, H Eding, H V Tieu, V C Cuong, C B A Wollny, L F Groeneveld, S Weigend
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  ABSTRACT: This study aimed to assess genetic diversity within and between nine Vietnamese local chicken breeds and two Chinese breeds included for comparison. Genotyping 29 microsatellites revealed high diversity of both Vietnamese and Chinese breeds. Cluster analysis using the STRUCTURE software suggested six clusters as the most likely grouping of the 11 breeds studied. These groups encompassed four homogeneous clusters, one formed by the two Chinese breeds and the other three representing a single breed each: the Mekong Delta breed Ac, the South Central Coast breed Choi, and the Red River Delta breed Dong Tao. The six remaining breeds formed two additional admixed clusters.
  Animal Genetics 10/2010; 41(5):545-7. · 2.40 Impact Factor
• Source

  Available from: Johannes A Lenstra

  Article: Genetic diversity in farm animals--a review.

  L F Groeneveld, J A Lenstra, H Eding, M A Toro, B Scherf, D Pilling, R Negrini, E K Finlay, H Jianlin, E Groeneveld, S Weigend
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  ABSTRACT: Domestication of livestock species and a long history of migrations, selection and adaptation have created an enormous variety of breeds. Conservation of these genetic resources relies on demographic characterization, recording of production environments and effective data management. In addition, molecular genetic studies allow a comparison of genetic diversity within and across breeds and a reconstruction of the history of breeds and ancestral populations. This has been summarized for cattle, yak, water buffalo, sheep, goats, camelids, pigs, horses, and chickens. Further progress is expected to benefit from advances in molecular technology.
  Animal Genetics 05/2010; 41 Suppl 1:6-31. · 2.40 Impact Factor
• Source

  Available from: scielo.org.za

  Article: A comparison of genetic diversity between South African conserved and field chicken populations using microsatellite markers

  B J Mtileni, F C Muchadeyi, S Weigend, A Maiwashe, E Groeneveld, L F Groeneveld, M Chimonyo, K Dzama
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  ABSTRACT: The objective of the study was to determine genetic diversity within South African indigenous chicken populations and the effectiveness of the current conservation flocks in capturing the available diversity in the founder populations. Two chicken populations, Venda (VD_C) and Ovambo (OV_C) conservation flocks (n = 56) from the Animal Production Institute in Irene and two founder population from which these conservation flocks were sampled; Venda (VD_F) and Ovambo (OV_F) field populations (n = 72) were genotyped for 29 autosomal microsatellite markers. All microsatellites typed were found to be polymorphic. A total of 213 alleles were observed for all four populations. The mean number of alleles per population ranged from 3.52 ± 1.09 (VD_C) to 6.62 ± 3.38 (OV_F). Mean observed (H O) and expected (H E) heterozygosity in the conservation flocks were 0.55 and 0.57 respectively. The corresponding values for the founder population were 0.62 and 0.68. The observed within population diversity measures indicated that field populations are more diverse than conservation flocks. The Reynolds genetic distance (D Reynolds) between conservation flocks and field population observed was 0.22 between VD_C and VD_F and 0.09 between OV_C and OV_F. STRUCTURE was used to cluster individuals to 2 ≤ K ≤ 5. The most probable clustering was found in K = 3, in which the populations were grouped into three clusters. VD_C and OV_C conservation flocks separated as independent clusters, while VD_F and OV_F field populations formed one cluster for any K value. Clustering analysis indicated a clear subdivision of the conservation flocks and field population into genetically distinct populations. The present study suggests that conservation flocks are less diverse compared to field populations.
  South African Journal Of Animal Science 01/2010; 40. · 0.24 Impact Factor
• Article: Genetic structure of a wide-spectrum chicken gene pool.

  Z Granevitze, J Hillel, M Feldman, A Six, H Eding, S Weigend
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  ABSTRACT: The genetic structure of 65 chicken populations was studied using 29 simple sequence repeat loci. Six main clusters which corresponded to geographical origins and histories were identified: Brown Egg Layers; predominantly Broilers; native Chinese breeds or breeds with recent Asian origin; predominantly breeds of European derivation; a small cluster containing populations with no common history and populations that had breeding history with White Leghorn. Another group of populations that shared their genome with several clusters was defined as 'Multi-clusters'. Gallus gallus gallus (Multi-clusters), one of the subspecies of the Red Jungle Fowl, which was previously suggested to be one of the ancestors of the domesticated chicken, has almost no shared loci with European and White Egg layer populations. In a further sub-clustering of the populations, discrimination between all the 65 populations was possible, and relationships between each were suggested. The genetic variation between populations was found to account for about 34% of the total genetic variation, 11% of the variation being between clusters and 23% being between populations within clusters. The suggested clusters may assist in future studies of genetic aspects of the chicken gene pool.
  Animal Genetics 07/2009; 40(5):686-93. · 2.40 Impact Factor
• Article: Genetic diversity of Hungarian indigenous chicken breeds based on microsatellite markers.

  N Bodzsar, H Eding, T Revay, A Hidas, S Weigend
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  ABSTRACT: Six local chicken breeds are registered in Hungary and are regarded as Hungarian national treasures: Hungarian White, Yellow and Speckled, and Transylvanian Naked Neck White, Black and Speckled. Three Hungarian academic institutes have maintained these genetic resources for more than 30 years. The Hungarian Yellow, the Hungarian Speckled and the Transylvanian Naked Neck Speckled breeds were kept as duplicates in two separate subpopulations since time of formation of conservation flocks at different institutes. In this study, we investigated genetic diversity of these nine Hungarian chicken populations using 29 microsatellite markers. We assessed degree of polymorphism and relationships within and between Hungarian breeds on the basis of molecular markers, and compared the Hungarian chicken populations with commercial lines and European local breeds. In total, 168 alleles were observed in the nine Hungarian populations. The F(ST) estimate indicated that about 22% of the total variation originated from variation between the Hungarian breeds. Clustering using structure software showed clear separation between the Hungarian populations. The most frequent solutions were found at K = 5 and K = 6, respectively, classifying the Transylvanian Naked Neck breeds as a separate group of populations. To identify genetic resources unique to Hungary, marker estimated kinships were estimated and a safe set analysis was performed. We show that the contribution of all Hungarian breeds together to the total diversity of a given set of populations was lower when added to the commercial lines than when added to the European set of breeds.
  Animal Genetics 05/2009; 40(4):516-23. · 2.40 Impact Factor
• Article: Variation in neighbouring genes of the dopaminergic and serotonergic systems affects feather pecking behaviour of laying hens.

  K Flisikowski, H Schwarzenbacher, M Wysocki, S Weigend, R Preisinger, J B Kjaer, R Fries
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  ABSTRACT: Feather pecking is a behavioural disorder of laying hens and has serious animal welfare and economic implications. One of the several aetiological hypotheses proposes that the disorder results from redirected exploratory behaviour. Variation in the gene encoding the dopamine D4 receptor (DRD4) has been shown to be associated with exploratory behaviour in several species, including in a passerine bird species. We therefore considered DRD4 as a candidate gene for feather pecking. We have annotated DRD4 in the chicken genome and have re-sequenced it in 140 animals belonging to: experimental layer lines divergently selected for high and low propensity to feather pecking; the unselected founder population; and two commercial lines with low and high propensity to feather pecking. We have identified two sub-haplotypes of DRD4 that are highly significantly associated with feather pecking behaviour in the experimental (P = 7.30 x 10(-7)) as well as in the commercial lines (P = 2.78 x 10(-6)). Linkage disequilibrium (LD) extends into a neighbouring gene encoding deformed epidermal autoregulatory factor 1 (DEAF1). The product of DEAF1 regulates the transcription of the gene encoding the serotonin (5-hydroxytryptamine) 1A receptor. Thus, DEAF1 represents another candidate gene for feather pecking. Re-sequencing of five animals homozygous for the 'low-pecking' sub-haplotype and of six animals homozygous for the 'high-pecking' sub-haplotype delineated an LD block of 14 833 bases spanning the two genes. None of the variants in the LD block is obviously functional. However, the haplotype information will be useful to select against the propensity to feather pecking in chicken and to elucidate the functional implications of the variants.
  Animal Genetics 01/2009; 40(2):192-9. · 2.40 Impact Factor
• Article: Mitochondrial DNA D-loop sequences suggest a Southeast Asian and Indian origin of Zimbabwean village chickens.

  F C Muchadeyi, H Eding, H Simianer, C B A Wollny, E Groeneveld, S Weigend
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  ABSTRACT: This study sought to assess mitochondrial DNA (mtDNA) diversity and phylogeographic structure of chickens from five agro-ecological zones of Zimbabwe. Furthermore, chickens from Zimbabwe were compared with populations from other geographical regions (Malawi, Sudan and Germany) and other management systems (broiler and layer purebred lines). Finally, haplotypes of these animals were aligned to chicken sequences, taken from GenBank, that reflected populations of presumed centres of domestication. A 455-bp fragment of the mtDNA D-loop region was sequenced in 283 chickens of 14 populations. Thirty-two variable sites that defined 34 haplotypes were observed. In Zimbabwean chickens, diversity within ecotypes accounted for 96.8% of the variation, indicating little differentiation between ecotypes. The 34 haplotypes clustered into three clades that corresponded to (i) Zimbabwean and Malawian chickens, (ii) broiler and layer purebred lines and Northwest European chickens, and (iii) a mixture of chickens from Zimbabwe, Sudan, Northwest Europe and the purebred lines. Diversity among clades explained more than 80% of the total variation. Results indicated the existence of two distinct maternal lineages evenly distributed among the five Zimbabwean chicken ecotypes. For one of these lineages, chickens from Zimbabwe and Malawi shared major haplotypes with chicken populations that have a Southeast Asian background. The second maternal lineage, probably from the Indian subcontinent, was common to the five Zimbabwean chicken ecotypes, Sudanese and Northwest European chickens as well as purebred broiler and layer chicken lines. A third maternal lineage excluded Zimbabwean and other African chickens and clustered with haplotypes presumably originating from South China.
  Animal Genetics 01/2009; 39(6):615-22. · 2.40 Impact Factor
• Source

  Available from: Han Jianlin

  Article: MITOCHONDRIAL DNA D-LOOP ANALYSIS OF SOUTH WESTERN NIGERIAN CHICKEN

  Analisis De, D-Loop Adn, Mitocondrial De, Pollos De, Sw Nigeria Adebambo, Bjørnstad, W Bulimo, H Jianlin, G Kierstein, L Mazhani, [......], R Sanfo, F Gaye, E Ssewanyana, Coulibaly, B Teme, O Hanotte, Rurale P O Box, Mohamed V Rue, Bamako, Mali
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  ABSTRACT: Mitochondrial DNA (mtDNA) D-loop segment was sequenced for a total of 98 individuals of domestic chicken from South Western Nigeria. Domestic chicken populations were: Anak titan (Israeli breed,n= 1), Frizzle (n= 16), Opipi (n= 5), FrizzleXOpipi (n= 5), Fulani (n= 4), Giriraja (Indian breed,n= 3), Normal (n= 55), Naked neck (n= 8), Yaffa (n= 1). The sequences of the first 397 nucleotides were used for the analysis. Seventeen haplotypes were identified in the samples, 15 for Nigerian indigenous chicken population, 1 for Giriraja and 1 for Anak titan from 23 polymorphic sites. Phylogenetic analysis shows that Nigerian indigenous and Anak titan chicken were all grouped under clade IV, while the Indian Giriraja was under clade IIIc. Clade IV had 16 haplotypes, while clade IIIc had one haplotype. AMOVA analysis indicates that 97.32% of the total sequence variation between haplotypes was present within population and 2.68% between populations. Our results suggest single multiple maternal origins for the South Western Nigerian domestic chicken.
  Arch. Zootec. 01/2009; 58:637-643.
• Article: Genetic resistance to Heterakis gallinarum in two chicken layer lines following a single dose infection.

  M Gauly, A Kanan, H Brandt, S Weigend, E Moors, G Erhardt
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  ABSTRACT: Groups of White Leghorn and New Hampshire male and female chicks were reared under helminth-free conditions and divided into two groups at an age of 8 weeks. One group was artificially infected with 100 embryonated Heterakis gallinarum eggs, while the other group was kept as uninfected control. After 8 weeks all animals were harvested and worm burden was established. Maximum of 60 worms per bird randomly selected were measured for length. Body weights were recorded at 8 and 16 weeks of age. Total worm burden was significantly (P<0.0001) higher in infected males than in infected females. Furthermore, White Leghorns showed a significantly (P=0.011) higher number of worms when compared with New Hampshire animals. Average worm lengths were not significantly different between the breeds (P=0.155) and sexes (P=0.062). Correlations between worm burden and worm length was 0.08 (P=0.140). The daily weight gains between 8 and 16 weeks of age of the infected animals were significantly (P=0.038) lower when compared with the control group. There was no significant correlation between daily weight gain and worm burden. The estimated heritabilities for logarithm (ln) worm burden were 0.41 (S.E.+/-0.086) in White Leghorn and 0.31 (S.E.+/-0.126) in New Hampshire, respectively. Based on the estimated heritabilities it is possible to select for H. gallinarum resistance in both genetically distinct chicken breeds. This approach may be of importance for chickens kept in floor husbandry systems.
  Veterinary Parasitology 08/2008; 155(1-2):74-9. · 2.58 Impact Factor
• Article: Choice of breeding stock, preference of production traits and culling criteria of village chickens among Zimbabwe agro-ecological zones.

  F C Muchadeyi, C B A Wollny, H Eding, S Weigend, H Simianer
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  ABSTRACT: Free ranging chickens reared by smallholder farmers represent genetic diversity suited for particular environments and shaped by the socio-economic and cultural values of the farming systems. This study sought to investigate the existence of chicken strains and evaluate the breeding goals and strategies used by village chicken farmers in Zimbabwe. A semi-structured questionnaire was administered to 97, 56, 70, 104 and 37 households randomly selected from five agro-ecological-zones I-V, respectively. Fifteen chicken strains mostly defined by morphological traits were reported in the five eco-zones. Production criteria such as body size, and fertility were highly ranked (ranging from 1.3-2.6) by farmers across all the eco-zones, while cultural traits were the least preferred production traits. As a common breeding practice, farmers chose the type of hens and cocks to retain for breeding purposes and these randomly mixed and mated with others from community flocks. Chicken body size was ranked the major determinant in choosing breeding animals followed by mothering ability, and fertility. More households culled chickens associated with poor reproductive performance, poor growth rates and those intolerant to disease pathogens. The focus on many negatively correlated production traits and the absence of farmer records compromises breeding strategies in these production systems.
  Tropical Animal Health and Production 08/2008; 41(3):403-12. · 1.12 Impact Factor
• Article: Genetic diversity within chicken populations from different continents and management histories.

  Z Granevitze, J Hillel, G H Chen, N T K Cuc, M Feldman, H Eding, S Weigend
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  ABSTRACT: Intra-population variation was assessed in 1970 chickens from 64 populations using 29 autosomal microsatellites. On average, 95% of the loci were polymorphic across populations. In 1456 (c. 83%) of the 1763 combinations of populations and polymorphic loci, no departure from Hardy-Weinberg equilibrium was observed. On average, there were 11.4 alleles per locus and 3.6 alleles per population across loci. Within populations, the average observed heterozygote frequency was 0.46, with a range between 0.20 and 0.64. Dagu, a Chinese population, and the Red Jungle Fowl (Gallus gallus gallus) had the highest average heterozygote frequencies at 0.64 and 0.63 respectively. An inbred line used as a reference population for comparison showed the lowest average of observed heterozygote frequency (0.05), followed by the European population Hamburger Lackhuhn, whose average observed heterozygote frequency was 0.20. A total of 32 private alleles (alleles detected in only one population) for 20 loci were found in 18 populations. H'mong chickens, a Vietnamese population, carried the largest number of private alleles at five, followed by the Red Jungle Fowl with four private alleles. Genetic diversity within populations was low in the NW European fancy breeds and high in the non-commercial Asian populations, in agreement with population management history.
  Animal Genetics 01/2008; 38(6):576-83. · 2.40 Impact Factor
• Source

  Available from: Herwin Eding

  Article: Variation in village chicken production systems among agro-ecological zones of Zimbabwe.

  F C Muchadeyi, C B A Wollny, H Eding, S Weigend, S M Makuza, H Simianer
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  ABSTRACT: The degree to which village chickens are integrated in the smallholder farming systems differs depending on the socio-economic, cultural and biological factors within each system. The objective of this study was to characterise the village chicken farming systems and identify possible threats to, and opportunities for, local chickens in the agro-ecological zones of Zimbabwe. A pre-tested questionnaire was administered to households randomly selected from five districts, Risitu (n=97), Hurungwe (n=56), Gutu (n=77), Gokwe-South (n=104) and Beitbridge (n=37) in eco-zones I-V, respectively. Age of head of household averaged 47 years (SD = 14.3). Land holdings per household averaged 4.82 ha (SD = 3.6). Overall, 17.7 percent of the households ranked livestock as the major source of income compared to 70.8 percent who ranked crops as the main contributor. Chicken flock size averaged 16.7 (SD = 12.4), and the highest flock sizes were observed in eco-zones I and IV. Households owning cattle, goats and other livestock assigned less important ranks to chickens. Chickens were usedmainly for the provision of meat and eggs whilst the use of chicken feathers and investment were uncommon practises. Results indicate that more support is necessary for village chickens in the non-cropping regions of the country.
  Tropical Animal Health and Production 09/2007; 39(6):453-61. · 1.12 Impact Factor
• Article: Absence of population substructuring in Zimbabwe chicken ecotypes inferred using microsatellite analysis.

  F C Muchadeyi, H Eding, C B A Wollny, E Groeneveld, S M Makuza, R Shamseldin, H Simianer, S Weigend
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  ABSTRACT: The objective of this study was to investigate the population structure of village chickens found in the five agro-ecological zones of Zimbabwe. Twenty-nine microsatellites were genotyped for chickens randomly selected from 13 populations, including the five eco-zones of Zimbabwe (n = 238), Malawi (n = 60), Sudan (n = 48) and six purebred lines (n = 180). A total of 280 alleles were observed in the 13 populations. Forty-eight of these alleles were unique to the Zimbabwe chicken ecotypes. The average number (+/-SD) of alleles/locus was 9.7 +/- 5.10. The overall heterozygote deficiency in the Zimbabwe chickens (F(IT) +/- SE) was 0.08 +/- 0.01, over 90% of which was due to within-ecotype deficit (F(IS)). Small Nei's standard genetic distances ranging from 0.02 to 0.05 were observed between Zimbabwe ecotypes compared with an average of 0.6 between purebred lines. The structure software program was used to cluster individuals to 2 </= K </= 7 assumed clusters. The most probable clustering was found at K = 6. Ninety-seven of 100 structure runs were identical, in which Malawi, Sudan and purebred lines split out as independent clusters and the five Zimbabwe ecotypes clustered into one population. The within-ecotype marker-estimated kinships (mean = 0.13) differed only slightly from the between-ecotype estimates. Results from this study lead to a rejection of the hypothesis that village chickens are substructured across agro-ecological zones but indicated high genetic diversity within the Zimbabwe chicken population.
  Animal Genetics 08/2007; 38(4):332-9. · 2.40 Impact Factor
• Source

  Available from: ddr.nal.usda.gov

  Article: Molecular markers for the assessment of chicken biodiversity

  J. HILLEL, Z. GRANEVITZE, T. TWITO, D. BEN-AVRAHAM, S. BLUM, U. LAVI, L. DAVID, M.W. FELDMAN, H. CHENG, S. WEIGEND
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  ABSTRACT: Three main aspects of chicken biodiversity are dealt within this report: (a) cluster analysis based on autosomal microsatellites, (b) microsatellites on the sex chromosomes, and (c) SNP-based biodiversity.(a) Cluster analysis of autosomal microsatellites: We used 29 microsatellites to genotype 2000 chickens randomly selected from 65 different populations representing various chicken types and various geographical regions. The computer program Structure placed the 65 populations into clusters that are in agreement with their geographic origin and breed history. Only at two predefined clusters, there is little admixture between non-commercial populations originating from Asia and those from Europe. In contrast, commercial broilers and brown egg layers appeared as admixed populations of these two main gene pools. Increasing the number of clusters resulted in generation of specific clusters of commercial lines, having very low admixture with other clusters. In addition, we identified seven mixed populations, each of which shared portions of their genome with several other genetic clusters.(b) Microsatellites on the sex chromosomes: We predicted 173 potential microsatellites on chromosome W by in-silico analysis of the chicken genome assembly (version WASHUC1). Twenty five microsatellites of the highest sequence quality were tested in the lab for gender specificity. Unexpectedly, PCR products were generated in both sexes. Moreover, 14 selected microsatellites were mapped (using the East Lansing reference panel) and in all cases, the “W specific” microsatellites were mapped to chromosome Z and except for one locus, to the same 6 cM region. We conclude that the draft assembly for chromosome W is quite inaccurate.(c) SNP-based biodiversity: Ten distinct chicken breeds were genotyped at 145 single nucleotide polymorphisms (SNPs) located at 14 random DNA fragments and twenty five, each from different and unlinked genes. Microsatellite genotypes of the same ten breeds were used for comparison. Applying bootstrap values as the criterion for tree's reliability, we found that: (1) increasing the number of SNPs had a higher impact on the reliability of the analysis than increasing the number of individuals per population, and (2) the bootstrap values of phylogenetic un-rooted trees based on microsatellites were relatively low.
  World's Poultry Science Journal 02/2007; 63(01):33 - 45.