AnGR Genetic improvement

Permanent URI for this collectionhttps://hdl.handle.net/10568/3843

Genetic diversity, Breeding strategies, Crossbreeding, Biotechnologies, Development projects, Trypanotolerance

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    Proceedings of the Interbull meeting Uppsala, Sweden, 2–4 June 2005
    (Journal Article, 2005) Interbull Centre
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    Analysis of methods for efficient biodiversity conservation with focus on African cattle breeds
    (Conference Paper, 2006) Reist-Marti, S.B.; Abdulai, A.; Simianer, H.
    Methods for biodiversity conservation are reported and applied to 49 African cattle breeds (26 taurine/sanga and 23 zebu/zenga (ZZ) breeds). It was estimated that about half of the breeds and half of today’s genetic diversity between breeds would be lost within 50 years. Based on a survey and a literature review, cost and effects of four conservation programmes were assessed: herd books combined with promotion of the breed (HB), in situ conservation with sire rotation (IS), cryoconservation of semen (CC) and in situ plus cryoconservation (IC). Conservation programmes involving strongly breeders, and giving them part of the responsibility for the conservation of the breed reduce endangerment. In this case Breeders were not just potential sellers of animals for a conservation program, but they participated actively in the program (e.g. take decisions) and took over part of the responsibility for the success of the program. It was shown that allocation of resources to only a subset of breeds is optimal. With US$ 2 million, 64% of the present diversity of the ZZ breeds could be maintained over 50 years, i.e. 13% more than if no action is taken.
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    Use of progesterone in early detection of open cows in smallholder dairy farms in Nakuru District of Kenya
    (Conference Paper, 2006) Indetie, D.; Indetie, A.; Kinyua, J.; Ojango, N.; Perera, O.
    Kenya’s smallholder dairy sector produces 85% of the total milk marketed in the country. A major constraint to milk production and number of calves born from the cows is the long calving intervals. Determining non-pregnant cows early by measuring progesterone levels by day 23 after insemination can help reduce calving intervals, thus improving productivity. A sample of 481 cows was inseminated and 10 ml milk samples collected from each cow on day 0, 13 and 23 after insemination to determine progesterone levels using radioimmunoassay and using I125 as the tracer. This was to determine timeliness of artificial insemination (AI), cyclicity and pregnancy by day 24 after AI. Rectal palpation was done 90 days after insemination to confirm hormone predictions for non-pregnancy. Conception rates of 53% were recorded. Mean progesterone levels were 0, 5.3 and 10.1 nm/litre at the three stages of sampling respectively for pregnant cows, while non-pregnant cows recorded 0.59, 2.69, 0.46 nm/litres respectively. Of cows inseminated at the right time, 38% did not conceive, showing a problem of cyclicity or early embryonic loss. Embryonic loss was recorded in 32% of non-pregnant cows. The post-partum period averaged 5 months. Breeds were similar for conception while cows inseminated during April to June had higher conceptions than those of July to September. Prediction accuracy of non-pregnant cows was 96%, thus, open cows can be identified early, reducing the time required to re-breed and hence reduce calving intervals.
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    Practical application of DNA technology to support livestock breeding in southern Africa
    (Conference Paper, 2006) Kotze, A.; Harris, E.J.; Soma, P.; Joubert, E.
    The development of molecular genetics, especially DNA technology, has created the opportunity for animal breeders to make use of the dramatic progress in agricultural biotechnology. The most applicable development in South Africa is DNA profiling. Through the analysis of unique banding patterns, applications such as individual identification, parentage verification, genetic characterisation and the detection of genetic defects and undesirable genes are performed. The results for the different farm animal species are stored in databases for reference. Parentage verification is determined very accurately and the results are used for the registration of animals. Direct information on the genotypes of polymorphic loci allows for the measurement of breed relationships. The screening of animals for genetic defects through the detection of single point mutations is discussed using examples from the dairy and pig industries. The use of DNA technology as a tool contributes to accurate information in breeding programmes that make use of genetically superior individuals while maintaining biological diversity.
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    Biotechnology in animal agriculture and poverty alleviation: An NGO perspective
    (Conference Paper, 2006) Bayer, W.; Wanyama, J.
    Biotechnology has only limited potential to alleviate poverty in rural Africa because it does not address the main reasons for poverty such as weak infrastructure, bad governance and unfavourable terms of trade. Looking at the main characteristics of the predominantly small-scale animal farming in Africa, the potentials and limitations for biotechnological applications in food processing, forage improvement, animal breeding and animal health are discussed. Indigenous biotechnology under the control of livestock farmers can be beneficial, whereas—with the exception of some animal health technologies—large-scale and ‘high-tech’ applications of biotechnology have shown little potential to alleviate poverty. Indeed, these applications can have the opposite effect. Rather than pouring an undue amount of human and financial resources into further refinement of advanced biotechnology, African livestock researchers should develop their own research agenda that addresses the real problems of small-scale livestock keepers and poverty alleviation.
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    Caprine milk protein polymorphisms: Possible applications for African goat breeding and preliminary data in Red Sokoto
    (Conference Paper, 2006) Ibeagha-Awemu, E.M.; Bemji, M.N.; Osinowo, O.A.; Chiatti, F.; Chessa, S.; Erhardt, G.
    About 70% of all milk consumed in sub-Saharan Africa is imported from other parts of the world. This trend may be reversed by encouraging production through marker assisted selection. Goats are second to cattle in milk production, they require less inputs and their small size make them attractive to smallholder production systems. This paper presents the current knowledge on milk protein polymorphisms in goats, including aS1-casein, aS2-casein, b-casein, k-casein, alactalbumin and b-lactoglobulin, and their relationships with milk quality, composition and technological properties. Moreover, the results of a preliminary investigation on milk samples from 48 Red Sokoto goats by isoelectrofocusing (IEF) are discussed. Three main alleles were detected at each of CSN1S1 and CSN1S2 loci and two IEF patterns at CSN3 locus. Finally, the paper makes recommendations for further exploitation of African goats for milk production considering the possibility for the genetic improvement of milk yield and composition, fulfilling both nutritional requirements and technological properties.
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    Accuracy of genetic prediction obtained using genetic relationships based on pedigree or marker information
    (Conference Paper, 2006) Maiwashe, A.; Garrick, D.J.
    The accuracy of genetic prediction when pedigree ( P A ) or pedigree and marker-based ( PM A ) relationships were used in mixed model equations was assessed. Daughter yield deviations (DYD) records for milk, fat and protein yields on Holstein sires (n = 1,811) with DNA marker information were analysed. Three sets of estimated breeding values (EBV) were obtained: (1) EBV-ALL (considered all sources of information and the inverse of), (2) EBV-PED (similar to EBV-ALL but the sire’s own DYD was excluded), and (3) EBV-MRK (similar to EBV-PED except that the inverse of was used). Linear and rank correlations were computed between EBV-ALL and EBVPED or EBV-MRK. The accuracy increased by 4.3% for milk yield but did not change for fat and protein yields when was replaced by for sires without sons. These results suggest that genetic markers may be used to enhance accuracy in genetic evaluation particularly for young animals.
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    Application of DNA and protein technology in animal forensics
    (Conference Paper, 2006) Mapholi, N.; Harris, E.J.; Kotze, A.
    In South Africa, the increasing incidence of stock theft and poaching, with the accompanying cruelty to animals, affects all sectors of the livestock farming, including the large commercial farmers, stud breeders and the smallholder rural farmers who may own one or two cattle. Animal forensics, which includes DNA and protein technologies, can provide a useful tool for identifying stolen animals. Protein and DNA based methods can be used to establish the identity, ownership, parentage and traceablitiy or origin of the species of individual animals, using samples of blood meat, hair and other tissues collected from crime scenes. DNA microsatellite marker sets are used to obtain DNA profiles. The PCR procedure provides for the analysis of minute quantities of DNA. The analysis of protein profiles provides a simple but powerful means for animal and species identification. The paper discusses cases where animal forensic techniques have led to successful convictions.
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    The role of research and a seed stock industry in the in situ conservation of livestock genetic resources
    (Conference Paper, 2006) Scholtz, M.M.
    Africa is richly endowed with large numbers of indigenous livestock breeds. However, there is a perception that a major constraint to livestock production is the limited genetic potential of these breeds. This paper uses the Nguni from South Africa as an example, and demonstrates the role of research in addressing such misconceptions. Initial studies on the Nguni in the early 1980s indicated that the Nguni has the shortest calving interval of all beef breeds and its efficiency exceeded that of most breeds. This resulted in a revived interest in the Nguni from the seed stock industry, and the Nguni is currently numerically the sixth largest beef breed in the country. The seed stock industry requires breeds to be competitive, hence a need for selection. This is in contrast to keeping animals in their natural state, which implies a breed should remain the same and be frozen in time.
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    Will vitrification be the biotechnology to cryopreserve cattle embryos in the future?
    (Conference Paper, 2006) Nedambale, T.L.
    Vitrification is a cryopreservation technique that could be an important tool in the application of reproductive biotechnologies in the 21st century. This review summarises recent efforts made in cryopreservation methodologies of cattle embryos. To date, a great deal of effort and experimentation has been devoted to improving assisted reproduction technologies (ART) such as in vitro produced embryos (IVPE), nuclear transfer cloning and cryopreservation, due to the increasing global economic importance of cattle. Consequently, large numbers of embryos are generated through IVPE and conventional superovulation without a corresponding number of synchronised recipients; subsequently, these embryos must be either preserved or discarded. Thus, it is essential to cryopreserve embryos for future use, thereby providing an effective method for the conservation of indigenous livestock, global genetic transport, gene banking, breeding line restoration, and for genetic rescue of endangered African indigenous livestock species. Developing an efficacious vitrification technique and improving cryopreservation protocols and their effectiveness for sustaining survival is an essential asset for preserving cattle embryos, both as a routine breeding alternative and to ensure stringent biosecurity.
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    The use of biotechnology in conservation of indigenous animal genetic resources in Mozambique
    (Conference Paper, 2006) Maciel, S.
    This paper discusses the potential use of biotechnology in the conservation and improvement of indigenous animal genetic resources. National herds, mostly in the hands of the rural communities, are made up mainly of indigenous breeds. Conservation of indigenous livestock must include cryopreservation of semen oocytes and embryos and associated technologies, besides maintenance of living populations. These should be, accompanied by characterisation studies both phenotypic and generic to better understand better existing breeds and prevent the eradication of breeds due to natural or man-made disasters as already happened in Mozambique and is still happening in some parts of the world. Within a clear livestock breeding policy, this would also ensure sustainable utilisation of the indigenous breeds which can result in poverty reduction and food security taking into account community’s intellectual property rights.
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