Reconstructing the origin and dispersal patterns of village chickens across East Africa: insights from autosomal markers

Unravelling the genetic history of any livestock species is central to understanding the origin, development and expansion of agricultural societies and economies. Domestic village chickens are widespread in Africa. Their close association with, and reliance on, humans for long-range dispersal makes the species an important biological marker in tracking cultural and trading contacts between human societies and civilizations across time. Archaezoological and linguistic evidence suggest a complex history of arrival and dispersion of the species on the continent, with mitochondrial DNA (mtDNA) D-loop analysis revealing the presence of five distinct haplogroups in East African village chickens. It supports the importance of the region in understanding the history of the species and indirectly of human interactions. Here, through a detailed analysis of 30 autosomal microsatellite markers genotyped in 657 village chickens from four East African countries (Kenya, Uganda, Ethiopia and Sudan), we identify three distinct autosomal gene pools (I, II and III). Gene pool I is predominantly found in Ethiopia and Sudan, while II and III occur in both Kenya and Uganda. A gradient of admixture for gene pools II and III between the Kenyan coast and Uganda's hinterland (P = 0.001) is observed, while gene pool I is clearly separated from the other two. We propose that these three gene pools represent genetic signatures of separate events in the history of the continent that relate to the arrival and dispersal of village chickens and humans across the region. Our results provide new insights on the history of chicken husbandry which has been shaped by terrestrial and maritime contacts between ancient and modern civilizations in Asia and East Africa

Prevalence of gastrointestinal parasites in communal goats from different agro-ecological zones of South Africa

Aim: A longitudinal study was conducted to assess the epidemiology of common gastrointestinal parasite (GIP) infections affecting goats in South Africa as influenced by agro-ecological zone (AEZ), sampling season, and the age and sex of animals. Materials and Methods: A total of 288 goats (101 male and 187 female) were randomly sampled during winter and summer in areas representing four AEZs (arid: 80; semi-arid: 76; humid: 62; and dry sub-humid: 70) of South Africa. Fecal samples from each animal were collected from the rectum, and the presence of GIP eggs was determined using a modified McMaster technique. A sample was considered positive when a minimum of one GIP egg was detected under the microscope. Fecal cultures were prepared, and infective larvae were collected and identified. The data were analyzed by MiniTab17 (2017) using the FREQ procedure, and the association between the independent factors and the prevalence of various GIPs were evaluated using the Pearson Chi-square test (p<0.05). Results: The overall prevalence of GIP in the present study was 37.1%, with a mean prevalence of 30.0, 26.4, 31.1, 36.6, and 59.6% for Eimeria spp., Trichuris, Strongyloides papillosus, Moniezia spp., and strongyles, respectively. There was a significant (p0.05) association was observed for the prevalence of Eimeria spp. and S. papillosus. A significant (p0.05) association between the other GIPs and sampling season. The prevalence of Eimeria spp. infection was higher in winter (34.0%) than in summer (26.0%). Conclusion: AEZs and goat age are the most important risk factors influencing GIP infections in South African communal goats. These epidemiological parameters are important for outlining effective parasite control management systems against these GIPs in goats

Nanomechanical characteristics of laser and arc melted AlCuFeNiSi high entropy alloy: a comparative study

The exploration of high-entropy alloy development for structural applications is a major requirement for the energy and transportation industries. The systematic strategy of designing high entropy alloys is not complete without considering the desired properties, the selection of the elements, the determination of the composition, and the choice of the manufacturing process for the production of high-performance materials. AlCuFeNiSi high-entropy alloys were prepared via laser metal deposition and arc melting. The nanomechanical and wear characteristics of arc-melted and laser-deposited AlCuFeNiSi high-entropy alloys were comparatively studied because a comprehensive understanding of their mechanical properties is not yet fully understood for structural applications in the energy industry. The empirical relationship between the laser power and the nanohardness was determined using the response surface methodology. The results showed that the high entropy alloys consisted of solid solution BCC and FCC phases. ANOVA showed that laser power had a significant effect on the nanohardness, increasing with an increase in laser power. The optimum laser process parameters to yield the best properties were obtained and backed up with experimental data to achieve a cost-effective design of experiments

Gastrointestinal parasite infection intensity and hematological parameters in South African communal indigenous goats in relation to anemia

Aim: The study was conducted to determine the intensity of gastrointestinal parasite (GIP) infections and hematological parameters in South African communal indigenous goats in relation to anemia. Materials and Methods: A total of 288 goats were randomly sampled in areas representing four agro-ecological zones. Fecal and blood samples were collected from the rectum and jugular vein, respectively, of each animal. The number of eggs per gram (EPG) and oocysts per gram (OPG) of feces and the hematological parameters were determined using the modified McMaster technique and a BC-2800Vet® automatic hematology analyzer, respectively. Data were analyzed using the repeated measures techniques of Minitab 17, modeling the covariance structure of the observed data. Results: Based on EPG and OPG, goats in humid zone were significantly infected (p<0.05) with strongyles, Eimeria, Moniezia, and Trichuris spp. Hematological parameters of goats in arid and humid zone were lower (p<0.05) than those in semi-arid and dry sub-humid zone. GIP infection intensities were higher (p<0.05) in young animals than in adult and suckling goats. GIP infection intensity was similar between goat sexes, while hematological parameters were higher (p<0.05) in females. Higher (p<0.05) infection intensities for strongyles (302.90 EPG) and Eimeria (216.09 EPG) were observed in winter compared to summer (strongyles: 302.90, Eimeria: 216.09 EPG). Higher (p<0.05) values for the hematological parameters were observed during summer compared to that in winter. Conclusion: GIP infection intensity in the winter could be associated with hypochromic and normocytic anemia which likely to affects suckling goats while in the summer could be associated with normochromic and normocytic anemia which likely to affect young goats

Conservation and utilisation of indigenous chicken genetic resources in Southern Africa

AgriwetenskappeVeekundige WetenskappePlease help us populate SUNScholar with the post print version of this article. It can be e-mailed to: [email protected]

Assessment of Genetic Diversity and Conservation in South African Indigenous Goat Ecotypes: A Review

Goats were amongst the first livestock to be domesticated more than 10,000 years ago for their meat, milk, skin, and fiber. They were introduced to Southern Africa by migrating nations from Central Africa to the south. Due to local adaptation to the different agro-ecological zones and selection, indigenous goats are identified as ecotypes within the indigenous veld goat breed. Their ability to thrive in a resource-limited production system and in challenging environmental conditions makes them valuable animal resources for small-scale and emerging farmers. They play important roles in household agriculture and cultural activities as well as in poverty alleviation. Studies have described the phenotypic and genetic variations in indigenous goats, targeting the major goat-producing regions and the breeds of South Africa. In turn, information is restricted to certain breeds and regions, and the experimental design is often not adequate to inform the conservation status and priorities in changing environments. Advances in genomics technologies have availed more opportunities for the assessment of the biodiversity, demographic histories, and detection regions associated with local adaptation. These technologies are essential for breeding and conservation strategies for sustainable production for food security. This review focuses on the status of indigenous goats in South Africa and the application of genomics technologies for characterization, with emphasis on prioritization for conservation and sustainable utilization

Performance of informal market sweet potato cultivars in on-farm trials in South Africa

Several new sweet potato cultivars have been released in South Africa from 2004 until 2011 with varietal traits suitable for the informal market. This paper reports on results of on-farm trials conducted to evaluate the cultivars in broader agro-ecologies in the country. The trials were conducted at 15 localities across the 2011/12 to 2014/15 planting seasons including six cultivars with varying flesh colours. Data collection included marketable and unmarketable storage root yield classes, dry mass, and taste acceptability. The sites were representative of cool subtropical and warm temperate regions. Statistical analysis included ANOVA, AMMI, Discriminant analysis (DA) and Principal component analysis (PCA). Significant effects were detected for locality*cultivar and region*cultivar interactions for total and marketable yield, and for cultivar only for marketable yield. The factor region was not significant. The mean marketable yield ranged from 13.1 to 19.0 t/ha, being highest for 199062.1 and Ndou, while Bophelo had average stable yield over a broad range of environments. The most prevalent unmarketable class was weevil damage (15.1%). The study demonstrated PCA and DA as quick analytical tools to associate quality traits with cultivars to facilitate cultivar recommendations. Bophelo and Ndou had been sold with success on local informal markets and have large potential to be promoted wider

Evaluation of Genetic Diversity in Dog Breeds Using Pedigree and Molecular Analysis: A Review

Domestic dogs are important for many economic and social reasons, and they have become a well-known model species for human disease. According to research, dog breeds exhibit significant levels of inbreeding and genetic diversity loss, decreasing the population’s ability to adapt in certain conditions, and indicating the need of conservation strategies. Before the development of molecular markers, pedigree information was used for genetic diversity management. In recent years, genomic tools are frequently applied for accurate estimation of genetic diversity and improved genetic conservation due to incomplete pedigrees and pedigree errors. The most frequently used molecular markers include PCR-based microsatellite markers (STRs) and DNA sequencing-based single-nucleotide polymorphism markers (SNP). The aim of this review was to highlight genetic diversity studies on dog breeds conducted using pedigree and molecular markers, as well as the importance of genetic diversity conservation in increasing the adaptability and survival of dog breed populations