Genetic Improvement of Dairy Cow Reproductive Performance

The welfare of cow along with profitability in production are important issues in sustainable animal breeding programmes. Along with an intense/intensive selection for increased milk yield, reproductive performance has declined in many countries, in part due to an unfavourable genetic relationship. The largely unchanged genetic trend in female fertility and calving traits for Scandinavian Red breeds shows that it is possible to avoid deterioration in these traits if they are properly considered in the breeding programme. Today's breeding is international with a global selection and extensive use of the best bulls. The Nordic countries have traditionally recorded and performed genetic evaluation for a broad range of functional traits including reproduction. In recent years many other countries have also implemented genetic evaluation for these traits. Thus, the relative emphasis of dairy cattle breeding objectives has gradually shifted from production to functional traits such as reproduction. Improved ways of recording traits, e.g. physiological measures, early indicator traits, assisted reproductive techniques and increased knowledge of genes and their regulation may improve the genetic selection strategies and have large impact on present and future genetic evaluation programmes. Extensive data bases with phenotypic recordings of traits for individuals and their pedigree are a prerequisite. Quantitative trait loci have been associated to the reproductive complex. Most important traits, including reproduction traits are regulated by a multitude of genes and environmental factors in a complex relationship, however. Genomic selection might therefore be important in future breeding programmes. Information on single nucleotide polymorphism has already been introduced in the selection programmes of some countries.     

Molecular characterization of breeds and its use in conservation

The conservation of farm animal resources is important for coping with future breeding needs and for facilitating the sustainable use of marginal areas. The increasing availability of molecular markers for most farm animal species and the development of techniques to analyse molecular variation is widening our capacity to characterise the genetic variation of breeds. In this paper we review the most popular molecular markers used in conservation and animal breeding studies, the different measures of genetic diversity that they provide, and their application for managing within-breed genetic diversity and for setting between-breed conservation priorities. We also address the relationship between genomic and marker heterozygosity, the relationship between molecular and quantitative measures of genetic diversity, and the characterization of breeds based on non-neutral markers.     

A global strategy of using molecular genetic information to improve genetics in livestock

Traditional breeding programmes have largely contributed to disseminate the benefits of several quantitative traits in livestock. In developing countries such as Indonesia where animal population scattered throughout the country, it is difficult to invest for molecular research. On the other side, yet, it is worthy asset for breeding purposes. Based on theory and evidence, it has been proved that those scattered population evolved different genetic adaptations in response to a given natural pressure selection. A global strategy can be applied to the use of molecular genetic information for identification of economically important value. The use of genetic markers or more effective of marker-assisted selection (MAS) for desired important traits would be more valuable and useful and even more efficient in important trait selection of superior livestock. DNA marker technology would be very useful when applied for quantitative trait identification. Marker-assisted selection can be used for enhancing conventional breeding and works best for the traits with low heritability such as in reproductive traits and disease resistance. Application of conventional breeding for lower heredity traits would not be efficient because of waiting longer for generation interval, expensive in measurements, more population and more employees needed. Study of quantitative trait loci mapping is early investment to improve genetic merit. It can be performed once but can be used for exploring many genetic traits with economically important values. An effective option is biotechnology application in livestock for the development of genetic varieties such as stress tolerance, growth and carcass traits. Application of biotechnology approaches will enable improvement in productivity, reduction in costs, enrichment of milk compositions and extension of shelf life products.     

Present status of the conservation of livestock genetic resources in Brazil

Brazil has various species of domestic animals, which developed from breeds brought by the Portuguese settlers soon after the discovery of the country. After being submitted to a long process of natural selection, these breeds present characteristics adapted to specific Brazilian environmental conditions, and are known as “criollo”, “local” or naturalized breeds. From the beginning of the 20th century, some exotic breeds, selected in temperate regions, have begun to be imported, and, although more productive, they do not have adaptive traits, such as resistance to disease and parasites found in the naturalized breeds. Even so, they gradually replaced the native breeds, to such an extent that the latter are in danger of extinction. To avoid further loss of this important genetic material, in 1983 the National Research Center for Genetic Resources and Biotechnology (Cenargen) of the Brazilian Agricultural Research Corporation (Embrapa) decided to include conservation of animal genetic resources among its priorities. The conservation activities have been conducted under the Brazilian Genetic Resources Network — Renargen, and is carried out by various research centres of Embrapa, universities and State research institutions, as well as by private farmers, with a single coordinator at national level, Cenargen. The in situ conservation of cattle, horses, buffaloes, donkeys, goats, sheep and pigs is being carried out by Conservation Nuclei, located in the animal's original habitat. Ex situ conservation is centred at the Brazilian Animal Germplasm Bank (AGB), kept at Cenargen. This is responsible for the storage of semen and embryos of various breeds of domestic animals threatened with extinction. Presently the AGB has almost 60,000 doses of semen and more than 250 embryos, as well as over 7000 DNA samples. An important challenge for this program is to increase awareness within the different segments of society in terms of the importance of the conservation of animal genetic resources. The development and evolution of Renargen and its efforts to facilitate the conservation of genetic resources of livestock in Brazil are described in this paper.     

Aspects of conservation of animal genetic resources — Italian experiencesAspects de la conservation des ressources génétiques animales — Les expériences ItaliennesAspekte der erhaltung tierischer genetischer ressourcen — Italienische erfahrungen

The major factors to be considered in developing programmes of conservation of animal genetic resources are considered. The principal causes of the success or failure of the programmes carried out so far in Italy are examined. Organizational and psychological aspects are particularly important in practice.     

Genetics of animal health and disease in cattle

There have been considerable recent advancements in animal breeding and genetics relevant to disease control in cattle, which can now be utilised as part of an overall programme for improved cattle health. This review summarises the contribution of genetic makeup to differences in resistance to many diseases affecting cattle. Significant genetic variation in susceptibility to disease does exist among cattle suggesting that genetic selection for improved resistance to disease will be fruitful. Deficiencies in accurately recorded data on individual animal susceptibility to disease are, however, currently hindering the inclusion of health and disease resistance traits in national breeding goals. Developments in 'omics' technologies, such as genomic selection, may help overcome some of the limitations of traditional breeding programmes and will be especially beneficial in breeding for lowly heritable disease traits that only manifest themselves following exposure to pathogens or environmental stressors in adulthood. However, access to large databases of phenotypes on health and disease will still be necessary. This review clearly shows that genetics make a significant contribution to the overall health and resistance to disease in cattle. Therefore, breeding programmes for improved animal health and disease resistance should be seen as an integral part of any overall national disease control strategy.     

Developing a typology for local cattle breed farmers in Europe

Recognizing cultural diversity among local breed farmers is crucial for the successful development and implementation of farm animal genetic resources FAnGr conservation policies and programmes. In this study based on survey data collected in the EUropean REgional CAttle breeds project from six European countries, a typology of local breed farmers was designed and profiles for each of the farmer types were developed to assist these policy needs. Three main farmer types were constructed: production‐oriented, product and service‐oriented and hobby‐oriented farmers. In addition, seven subtypes were characterized under the main types: sustainable producers, opportunists, multi‐users, brand makers, traditionalists, pragmatists and newcomers. These types have many similarities to the ‘productivist’, ‘multifunctional’ and ‘post‐productivist’ farmer types. The typology not only reveals the high level of diversity among local cattle breed farmers in Europe, which presents an opportunity for the in situ conservation of animal genetic resources, but also a challenge for policy to meet the differing requirements of the farmer types.     

Animal health studies using participatory epidemiology in the Mandrare Valley, Madagascar

Pastoral herders in Madagascar have limited access to animal health workers and veterinary medicines, and more information on their livestock diseases is needed, so that effective animal health programmes can be implemented. In this study, participatory epidemiology methods were used to gather such information in the Mandrare Valley. These included pair-wise ranking and matrix scoring. Eleven diseases were deemed to be priorities by pair-wise ranking. Matrix scoring and characterisation showed that the informant groups associated many disease syndromes with the same diseases, indicating agreement and understanding of the key diseases. The Malagasy-named syndromes, Soko, Besorko and Mamany lio, which are gastrointestinal parasitism, clostridial disease and babesiosis, respectively, were identified by every informant group. A greater sample size may be needed to characterise the diseases precisely with matrix scoring because, in this study, the matrices’ scores had wide confidence intervals.     

Investigating maternal effects on production traits in Duroc pigs using animal and sire models

Variance components for production traits were estimated using different models to evaluate maternal effects. Data analysed were records from the South African pig performance testing scheme on 22 224 pigs from 18 herds, tested between 1990 and 2008. The traits analysed were backfat thickness (BFAT), test period weight gain (TPG), lifetime weight gain (LTG), test period feed conversion ratio (FCR) and age at slaughter (AGES). Data analyses were performed by REML procedures in ASREML, where random effects were successively fitted into animal and sire models to produce different models. The first animal model had one random effect, the direct genetic effects, while the additional random effects were maternal genetic and maternal permanent environmental effects. In the sire model, the random effects fitted were sire and maternal grand sire effects. The best model considered the covariance between direct and maternal genetic effects or between sire and maternal grand sire effects. Fitting maternal genetic effects into the animal model reduced total additive variance, while the total additive variance increased when maternal grand sire effects were fitted into the sire model. The correlations between direct and maternal genetic effects were all negative, indicating antagonism between these effects, hence the need to consider both effects in selection programmes. Direct genetic correlations were higher than other correlations, except for maternal genetic correlations of FCR with TPG, LTG and AGES. There has been direct genetic improvement and almost constant maternal ability in production traits as shown by trends for estimated (EBVs) and maternal breeding values (MBVs), while phenotypic trends were similar to those for EBVs. These results suggest that maternal genetic effects should be included in selection programmes for these production traits. Therefore, the animal–maternal model may be the most appropriate model to use when estimating genetic parameters for production traits in this population.     

Marker-based selection within smallholder production systems in developing countries

Livestock plays an important role in the livelihoods of millions of poor smallholders within developing countries. Although it has been recognized that smallholders could benefit from genetic improvement strategies (breeding programmes), the challenges associated with establishing genetic improvement strategies for smallholder systems are considerable, resulting in limited successes to date. This paper considers the potential role of marker-based selection to genetic improvement strategies for smallholder production systems, taking into account the socio-economic, infrastructural and institutional issues. The paper stresses that no genetic improvement strategy, with or without the use of markers, is likely to succeed unless a systems approach is applied and other system constraints are met. The marker-based selection technologies discussed in this paper include marker- and gene-assisted selection, marker-assisted introgression and genomic selection. The issues addressed include the priorities of marker-based selection against other genetic improvement strategies, the potential benefits of these technologies to smallholder producers, and conditions under which marker-based selection will most likely succeed in smallholder production systems. We suggest that, of these marker-based selection technologies, marker-assisted introgression and the emerging technology of genomic selection appear to offer the most promise to smallholders, although this is yet to be clearly demonstrated. In relation to genomic selection, developing countries should maintain a ‘watching brief’ on this technology, but simultaneously act now so that they can capitalize on this technology if and when it becomes applicable in the future.     

Epizootics in Industrial Livestock Production: Preventable Gaps in Biosecurity and Biocontainment

While technological advances in animal husbandry have facilitated increases in global meat production, the high density and geographic concentration of food animal production facilities pose risks of infectious disease transmission. The scale of the 2014–2015 highly pathogenic avian influenza H5N2 outbreak in the United States demonstrates the challenges in achieving pathogen control within and around industrial animal facilities using existing technologies. We discuss gaps in current practice in two specific systems within these facilities – ventilation and waste management – which are under‐recognized as important drivers of microbial porosity. The development of innovative ventilation systems to reduce influx and efflux of pathogens is critically needed, and cross‐sectoral partnerships should be incentivized to do so. Adapting current human biosolid treatment technologies for farm applications, reducing animal stocking density and shifting waste management responsibility from farmer to corporation would reduce risk from current manure management systems. While innovative approaches to functionally altering the industrial food animal production system remain important priorities to promote sustainability, our intention here is to identify gaps within the current system that allow for pathogen emergence and transmission and address specific areas in which technological, administrative or policy changes are necessary to mitigate these risks.     

Conservation of animal genetic resources — A reviewLa conservation des resources génétiques animalesErhaltunf genetischer tierressourcen

The success in breeding highly productive farm animals has resulted in a situation where animal breeders and other people consider it necessary to preserve less productive breeds. Arguments for conservation cover emotional, cultural and scientific reasons, as well as the concern of losing genetic material which could be valuable for future animal production. Costs and time require priorities for objectives, species and forms of conservation. International co-operation in documentation, evaluation, and conservation of genetic material seems necessary to ensure efficiency of actions.     

Genetic Engineering Approaches to Pig Production*

Modern biotechnology promises a number of new applications in animal breeding and production. Although conventional pig breeding has achieved a high level of efficiency and productivity numerous problems have been encountered with animal health and the loss of meat quality. Selection based on phenotypic performance data of individual animals does not take into account the importance of specific genes and their relevance within a complex regulatory system. In most cases it is therefore difficult to trace back the genetic origins of clinically important disorders. The application of genetic engineering techniques in pig production will facilitate diagnosis, improvement of productivity, and animal health by allowing direct genetic manipulation. Attention must be focussed on the physical and genetic analysis of the procine genome. The isolation and characterisation of genes, DNA-markers, polymorphic DNA-fragments, and their chromosomal assignment will be important prerequisites and tools for the elucidation of genetic disorders. Especially the detection of heterozygous carriers of recessive disorders and their elimination from the breeding stock will increase selection accuracy and decrease the generation intervals. But also the rapid and simple detection of infectious diseases, which is sometimes difficult if not impossible at present, will improve animal health and welfare. Although the production of transgenic animals either by DNA-microinjection into zygotes or the use of embryonal stem cells manipulated in vitro is less straightforward than DNA-based diagnosis it will play an important role in the direct manipulation of the porcine genome and genes. Breeding programmes including the use of transgenic livestock have already been developed. There is no doubt that genetic engineering has reached a degree of practical feasibility, allowing it to play an important role in pig breeding in particular and animal production in general.     

Poverty impacts of foot-and-mouth disease and the poverty reduction implications of its control

Foot-and-mouth disease (FMD) remains one of the most important livestock diseases of the world, given its highly infectious nature, its broad economic impacts on animal wellbeing and productivity, and its implications for successful access to domestic and export markets for livestock and products. The impacts of the disease vary markedly between developed and developing countries, and also within many developing countries. These differences in impact shape some markedly heterogeneous incentives for FMD control and eradication, which become of particular importance when setting priorities for poverty reduction in developing countries. Some consider that the benefits from FMD control accrue only to the better off in such societies and, as such, may not be a priority for investments targeted at poverty reduction. But is that view justified? Others see the control of FMD as a major development opportunity in a globalised environment. In this paper, Brian Perry and Karl Rich summarise the differential impacts of FMD and its control, and link these findings with the growing understanding of how the control of this globally important disease may contribute to the processes of pro-poor growth in certain countries of the developing world.     

Assessing Knowledge Production for Agrosilvopastoral Systems in South America

In recent decades agroforestry has undergone significant development in Latin America. South America generates the most scientific research on the topic in the region. We conducted a comprehensive review and analysis of knowledge production for South American agroforestry that includes livestock grazing, known as agrosilvopastoralism (AS), examining how different sociopolitical factors such as sources of funding, institutional priorities, and international cooperation can bias the direction and objectives of scientific research. We assessed the major attributes of scientific publications on the topic (25 articles per country; overall n = 210) and the potential factors underlying the processes of research and development in the region. The tree component was the most studied, while the livestock component received less attention. Studies were mainly focused on the production of goods and services (monetary or nonmonetary approaches), except in Brazil, where conservation was the major study objective. Stakeholders were involved in more than half of the studies (60%), and they were mostly ranchers and local producers. More than half (70%) of the studies offered recommendations based on their results, and such recommendations were mostly concerned with the management of agrosilvopastoral system components. In general, studies were led just as often by local as foreign first authors and coauthored by more than three people as part of interinstitutional working groups. Brazil, Argentina, Colombia, and Chile had more frequent cooperation among institutions and countries but mainly used their own funding. In contrast, Bolivia, Ecuador, and Peru had almost 100% of their studies supported by foreign countries (North America and Europe). Countries with greater internal funding of research generated more long-term studies. Besides this, two clear trends were detected: 1) conservation and social aspects were mainly supported by sources from external countries led by foreign principal investigators, and 2) production issues were supported from sources within countries and supported high levels of cooperation among institutions.     

Economic evaluation for conservation of farm animal genetic resources

The decline in biodiversity of farm animal genetic resources (AnGR) has come to the forefront of concern in the discussion of animal conservation and breeding programmes. To improve decision‐making regarding conservation and breeding programmes, a number of evaluation techniques of farm AnGR are available. This paper presents an overview of the different values associated to AnGR and of the techniques for their measurement being employed in the economic literature. Those include linear programming and farm simulation models, dynamic models estimating the value of research and development and econometric models estimating the demand for breed characteristics. While farm programming and simulation models are fairly well developed, they do have large data requirements. Alternatively, contingent valuation methods are available, in particular when the goal is to capture non‐market values embedded in breeds.     

Aggregate diversity: New approach combining within- and between-breed genetic diversity

Between-breed genetic diversity is classically considered as a major criterion to be taken into account when setting priorities for conservation of domestic animal breeds. However, it has been argued that methods based on the between-breed component of genetic diversity may not be optimal because they ignore the within-breed component of variation. The paper considers the most common methods used to evaluate those two components when genetic diversity is evaluated on the basis of genetic markers, and proposes to define an aggregate diversity combining linearly the two components. This implies defining for each breed (or population) its contributions to the between-breed and to the within-breed diversity. When defining an aggregate diversity, one can weight these contributions by F_ST and 1−F_ST, respectively, since the fixation index F_ST of Wright represents the proportion of the total genetic variation which is due to differences in allelic frequencies between populations. Such an approach is valid when the objective is genetic improvement by selection within a so-called “meta-population”. However, in a more general context of animal breeding, when heterosis and complementarities between breeds have to be considered, as well as adaptation to specific environments, more weight should be given to the between-breed variation. The proper weight to apply may require solutions adapted to each particular situation. In a long-term conservation perspective, priorities should also take into account the degree of endangerment of each breed. By combining diversity contributions and probability of extinction, a cryopreservation potential (or priority) may be estimated for each breed. The problem is illustrated on a sample of 11 European pig breeds typed for 18 microsatellite loci.     

畜禽遗传资源的经济价值评估

畜禽遗传资源的生物多样性的减少正在成为动物保护和品种改良研究中最受关注的问题。为了提高动物保护和育种方案的决策制定能力,各国的学者提出了许多相关的经济价值评估方法。本文从经济学角度分析了畜禽遗传资源的经济价值及其范畴,对其相关的评估方法进行了回顾。其中包括线性规划与农场模拟模型、估计研究和发展价值的动态模型以及估计育种性状需求的计量经济学模型等内容。农场规划和模拟模型已经发展得很完善,但它们需要大量的数据信息。目前最可取的方法是假设价值评估方法,当目标为获取品种的非市场经济价值时尤其如此。     

细菌人工染色体(BAC)文库在畜禽遗传资源保存中的应用

作者介绍了国际畜禽遗传资源保存的研究现状与趋势,分析了细菌人工染色体(bacterial artificial chromosome,BAC)文库的发展和应用状况,阐述了BAC文库应用于畜禽遗传资源保存的特有优势,提出了建立BAC文库将成为畜禽遗传资源保存的一种重要补充形式,有利于提升畜禽遗传资源保存的安全性和长久性,也为今后进一步研究畜禽品种的特定性状提供了无可替代的材料,对实现全方位保存畜禽遗传资源具有重要的实用价值和推动作用。     

畜禽遗传资源保护的国际法律法规体系研究

随着科技和现代生物技术的迅猛发展,国际竞争会越来越激烈.包括畜禽在内的生物遗传资源已成为一个国家可持续发展的重要战略资源,资源的拥有国对该资源具有国家主权.国际社会对生物资源也十分重视,有关生物遗传资源的许多国际公约、条约等法律法规相继签署生效,促进了全球畜禽遗传资源的管理、保存和利用.本文对联合国(UN)、世界贸易组织(WTO)以及世界知识产权组织(WIPO)等国际组织相关的畜禽遗传资源管理方面的法律法规进行了研究,通过分析各项法律法规的宗旨、目标、应用条件和适用范围以及国际立法新的方向,为更有效地保护我国畜禽遗传资源,以及进行全面管理、利用和国际交流提供法律方面的参考.