Assessing genetic diversity of Vietnamese local chicken breeds using microsatellites.

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.

Choice of breeding stock, preference of production traits and culling criteria of village chickens among Zimbabwe agro-ecological zones.

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.

Mitochondrial DNA D-loop sequences suggest a Southeast Asian and Indian origin of Zimbabwean village chickens.

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.

Prevalence and burden of gastrointestinal helminthes among local chickens, in northern Jordan.

We conducted a cross-sectional study from December 2004 to February 2005 and from June 2005 to August 2005. The study aimed to determine the prevalence of gastrointestinal and tracheal helminthes among local chickens in northern Jordan. A total of 208 male and female local scavenging chickens were selected randomly. We examined the trachea and gastrointestinal tract of each bird for the presence of helminthes. We recovered three nematode and eight cestode species. No trematodes were found. One hundred and fifty-two birds (73.1%) (95% CI: 67, 79) were infected. The prevalences of different species were as follows: Ascaridia galli female 28%, male 43%; Capillaria obsignata 0.5%; Heterakis gallinarum 33%; Amoebotaenia cuneata 4.3%; Choanotaenia infundibulum female 23%, male 13%; Davainea proglottina 1.4%; Hymenolepsis cantaniana 11%; Hymenolepsis carioca female 35%, male 24%; Raillietina cesticillius female 5%, male 11%; Raillietina echinobothrida 16%; and Raillietina tetragona 18%. The prevalences of A. galli and R. cesticillus were higher in male than female hosts while those of C. infundibulum and H. carioca were higher in females. The median worm burden was 7 (range 0-168) worms per chicken.

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

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.

Characterization of local chicken production systems and their potential under different levels of management practice in Jordan.

This study aimed to characterize the local chickens and their production systems and to investigate the opportunities for improvement. The study was carried out in 18 villages in northern Jordan with the participation of 120 households. Data were collected by individual interviews and surveys supported with structured questionnaires. A scoring system was developed to study the effect of different levels of management on chicken performance. The main reasons for keep local chickens were egg production and generation of income. The main features of the production systems were improper housing and inadequate hygiene. Newcastle disease, predators, and parasites were the main causes of flock losses. Purchasing rate was controlled by the chickens' phenotype, sex and age, and by season of year. The average flock size was 41.6 (+/-32.9) chickens per household, with a hen:cock ratio of 6.4:1. The average effective population size was 15.35, which indicated a high rate of inbreeding (5.52%). The main selection criterion adopted by farmers was egg production. There were positive significant correlations (p<0.001) between management level and chickens' performance. Hatchability, survivability, flock size, number of clutches, egg weight and egg mass were the major parameters that improved significantly with improvement in management level. Local chickens fulfil significant functions in the livelihood of rural smallholders; however, many constraints affected the efficiency of the production systems. Solutions should start with improving the management practices and establishing an effective breeding system.

Absence of population substructuring in Zimbabwe chicken ecotypes inferred using microsatellite analysis.

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

Local chicken production system in Malawi: household flock structure, dynamics, management and health.

Household flocks of scavenging chickens were monitored from August 2002 to August 2003 in 27 villages in Lilongwe, Malawi. The objective was to evaluate the local chicken production system by investigating flock structure, utilization, management and constraints. Farmers and researchers jointly obtained data on household flocks. Mean flock size was 12.9, with a range of 1-61 chickens. The flock dynamics of chickens over 8 weeks old constituted 91% migrating out of flocks and 9% into the flocks. Primary functions based on flock dynamics were, in order of importance, household consumption, participation in socio-cultural ceremonies, selling, exchanging breeding stock and gifts. Of the flock exits, 43.9% were due to losses from diseases, predation and theft. Most flocks (85%) were housed in human dwelling units. Scavenging was the main source of feed. The majority (77.6%) of farmers supplemented their chickens erratically with energy-rich feeds, mostly maize bran. Most supplementation took place during the cold-dry season. Village chicken production offers diverse functional outputs but faces animal health (diseases, parasites, predation) and management (feeding) constraints, which require an integrated intervention approach at community and household level.

Response of two breeds of chickens to Ascaridia galli infections from two geographic sources.

Comparative resistance to different isolates of Ascaridia galli was investigated in a local chicken breed from Jordan (LC) and in the Lohmann LSL white chicken (LW) strain. In two trials, birds of LC and LW were inoculated orally at 1-day old with 250 embryonated A. galli eggs. In the first trial a German source of A. galli was used, whereas in the second trial, a Jordan source of A. galli was used. At week 7 of infection, infected LC birds harbored significantly (P<0.05) fewer worms and excreted less A. galli eggs than infected LW birds. A. galli isolated from Jordan were less infectious than A. galli from Germany. Results suggest that the variation in genetic background between LC and LW is involved in the resistance to A. galli infection. A. galli isolates from different geographic areas differ in their ability to infect different chicken genotypes.