Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

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Farmers’ willingness to invest in livestock disease control: the case of voluntary vaccination against bluetongue
Sok, Jaap - \ 2017
University. Promotor(en): Alfons Oude Lansink; Henk Hogeveen, co-promotor(en): Armin Elbers. - Wageningen : Wageningen University - ISBN 9789463437059 - 214
business economics - farmers - livestock - vaccination - bluetongue virus - animal diseases - animal disease prevention - netherlands - bedrijfseconomie - boeren - vee - vaccinatie - bluetonguevirus - dierziekten - dierziektepreventie - nederland

Animal health authorities in the European Union nowadays consider voluntary approaches based on a neoliberal model of cost and responsibility sharing as a tool for controlling livestock diseases. Policy makers aim for policies that are soft and optional, and use insights from behavioural economics and social psychology. Voluntary approaches are flexible in terms of legislation and can be effective at lower costs, provided that farmers are willing to participate. In 2008, the Dutch animal health authorities used a voluntary vaccination approach to control an emerging bluetongue epidemic that started end of 2006. Nearly 60,000 holdings with ruminants were already affected by the end of 2007 and experts indicated that transmission could only be stopped through mass vaccination. Farmers were motivated to participate by informational and financial, incentive-based policy instruments.

Economic theory predicts that farmers underinvest in private disease control measures in the presence of externalities. These studies, however, assume farmers only consider the private economic motives and that they only can be extrinsically motivated via (monetary) incentives. If the willingness to invest in livestock disease control is also driven by intrinsic and social motives, this could imply that not only financial compensation, but a mix of policy instruments is needed to make voluntary approaches work.

The overarching research objective of this thesis was to assess the key determinants of farmers’ willingness to vaccinate against bluetongue and study the impact of different policy designs on the effectiveness of voluntary vaccination approaches to bluetongue disease control.

A three-stage research approach was conducted. Two models of decision making, one from economics and one from social psychology, were first applied to the case study to obtain a solid understanding of important perceptions and motivations that farmers have to invest in livestock disease control. These motivations (sometimes incentives) and perceptions were then related to different attributes of a vaccination scheme to have a better understanding of how a higher uptake can be obtained. In the third stage, the effect of the interplay between farmers’ collective behaviour and disease epidemiology on disease rate and vaccination uptake was studied.

Expected utility theory was used in combination with decision analysis and Monte Carlo simulation in chapter 2. The economic risk and monetary outcomes of the vaccination decision were considered, intrinsic or social motives ignored. The theoretical expectation from the analysis is that with high probabilities of herd exposure and disease effects at the start of the outbreak the farmer decides to vaccinate. Re-vaccination is uncertain during the course of the epidemic due to a lower probability of herd exposure and enduring protection against infection from previous vaccination. Factors that make re-vaccination more likely to happen are risk-averse behaviour and farm management aimed at the export of heifers. The decision moment – before or during an epidemic – and the characteristics of the disease – endemic, epidemic or emerging – are important factors in perceptions of disease risk.

Chapters 3 to 5 used data from a survey that was based on the reasoned action approach. Data were analysed with a variety of statistical, mostly multivariate, techniques. The relative importance of the social-psychological constructs in predicting the intention to participate in a hypothetical reactive vaccination scheme against bluetongue was assessed in chapter 3. It was found that intended vaccination behaviour was mainly explained by farmers’ attitude, but also by social pressures from injunctive and descriptive norms. Perceived behavioural control was the least important predictor of intention.

The most influential beliefs underlying the social-psychological constructs were assessed in chapter 4. Results suggested that instrumental beliefs (e.g. risk reduction) as well as experiential beliefs (e.g. animal welfare) were important drivers of the attitude towards vaccination against bluetongue. This indicates that in addition to monetary outcomes of the decision, at least a group of farmers also consider the non-monetary (or non-pecuniary) outcomes. The results further showed that the most influencing referents for the farmer are the veterinarian, his or her family members and colleague dairy farmers (peers). Two influencing control beliefs were associated with the provision of information and perceived trust and confidence in the vaccine safety, effectiveness and government approach to control the disease.

The aim of chapter 5 was to explore factors that could explain heterogeneity in farmers’ attitudinal beliefs. In particular, perceived risk, measured by a relative risk attitude and risk perception, and the Big Five personality traits were associated with variability in these beliefs. Conscientiousness discriminated farmers into a group of ‘vaccination intenders’ and non-intenders although it remained somewhat unclear how it relates to the decision problem, as it can be a sense of duty, achievement striving or both. The perceived risk measures were related to the milk production intensity and also discriminated intenders from non-intenders. These differences in perceived risk indicated that farmers might not be commonly risk averse, however, it is important to account for the domain specificity of risk taking behaviour.

A survey-based discrete choice experiment was used in chapter 6 to study more deeply farmers’ choices for different voluntary bluetongue vaccination scheme designs. A generalised random utility model of farmers’ behaviour allowed for heterogeneity in motives to invest in bluetongue disease control. Results showed that farmers have private economic motives (incentives) to participate in a vaccination scheme, such as to insure the production risk from disease infection and to maintain the export of heifers.

Interaction effects found between social-psychological constructs and specific designs of policy instruments highlighted the importance of perceived trust and confidence in the vaccine safety and effectiveness and in the disease control strategy chosen by animal health authorities. Attitude interacted positively with government communication (information) provided via veterinarians. Descriptive norm interacted positively with a lower perceived probability of adverse effects. This suggests that farmers are more likely to vaccinate if they perceive that others in their social network perform vaccination without experiencing adverse effects. Injunctive norm interacted negatively with a higher level of government subsidy. This suggested a crowding-out mechanism through which subsidization adversely affect farmer’s motivation to comply with the vaccination policy.

The interplay between farmers’ collective behaviour and bluetongue disease epidemiology was studied in chapter 7 with an agent-based model. The utility model specification from chapter 6 was used to describe the decision-making process of farmers. Other components that added to the dynamic nature of the model were a social network structure of the diffusion process of sharing information about vaccination status and a susceptible-latent-infectious-recovered model of disease spread. The effectiveness of different bluetongue vaccinations scheme designs was studied as measured by disease rate and vaccination uptake.

Results of chapter 7 showed that vaccination schemes that focus more on motivating farmers via informational instruments were somewhat more effective than predicted from the comparative static analysis in chapter 6. Motivation via financial incentives resulted in a somewhat lower effectiveness than was predicted from that same model. This might be explained as an emergent effect that evolves under specific vaccination scheme designs from the interactions between farmers themselves and with the environment from which they observe the progress of the disease. These schemes focus more on serving the information needs of farmers and raising the perceived trust and confidence in the disease control approach rather than on incentivising with higher levels of subsidy.

Three themes for livestock disease control emerged from the synthesis of the results in chapter 8, which were subsequently discussed in relation to the wider economic and (social) psychological literature. These themes coincide with shortcoming of the standard economic model of rational choice to describe and predict behaviour. The first theme was about understanding how farmers cope with risk in the context of livestock diseases. The second theme focused on the usefulness of financial compensation as a policy instrument. The third theme discussed the role of trust and social norms. After discussing the implications for policy making, main scientific contributions and suggestions for future research, the chapter concluded that:

Dutch dairy farmers who operate large-scale and intensive farms or keep heifers for export are likely to have private economic motives to vaccinate against bluetongue (Chapter 2, 4, 5 and 6).Farmers’ willingness to vaccinate against bluetongue is mostly driven by attitude, followed by perceived social pressures from injunctive norms and descriptive norms. This implies farmers can be motivated intrinsically, extrinsically, or both (Chapter 3).Dutch dairy farmers have intrinsic motives to vaccinate against bluetongue. They do not want to be confronted with animal suffering but want to keep job satisfaction high from working with healthy animals (Chapter 4).Dutch dairy farmers have social motives to vaccinate against bluetongue. They consider what important referents, such as the veterinarian or family members, think they should do and take into account the perceived behaviour of peers (Chapter 3 and 4).

Perceived risk, personality traits and past behaviour are important behavioural variables for explaining the heterogeneity in beliefs to vaccinate against bluetongue (Chapter 5).

The efficacy of financial, incentive based instruments to motivate to vaccinate against bluetongue is heterogeneous and not necessarily positive for each farmer. They are not effective if farmers already expect a positive net benefit from vaccination or if they crowd-out the motivation to comply with the vaccination policy (Chapter 2, 4, 6, 7).

The efficacy of informational policy instruments to motivate farmers to vaccinate against bluetongue is positively affected by farmers’ attitude towards vaccination and in case farmers perceive the communication channels used as credible and trustworthy (Chapter 3, 4, 6).

The efficacy of social interaction mechanisms in policy making, such as the perceived social pressuretovaccinateagainstbluetongue,ispositivelyaffectedbyfarmers’trustandconfidence in the government approach to control the disease (Chapter 4, 6, 7).

Forest-grassland transitions : How livestock and fire shape grassy biomes
Bernardi, Rafael E. - \ 2017
University. Promotor(en): Marten Scheffer, co-promotor(en): Milena Holmgren Urba; Matías Arim. - Wageningen : Wageningen University - ISBN 9789463436212 - 129
forests - grasslands - fire - cattle - livestock - subtropics - south america - trees - bossen - graslanden - brand - rundvee - vee - subtropen - zuid-amerika - bomen

Plant associations are determined by complex interactions with their environment depending on resource availability, landscape features, and periodic disturbances that shape the structure and functions of these communities. Forests, savannas and grasslands extend across the global land surface, contribute to planetary processes and provide ecosystems services sustaining local production. However, the factors that explain the distribution of trees and determine these biomes are still not well understood. In this thesis, long-standing questions about the origins and distribution of these ecosystems are discussed in light of new evidence suggesting that a feedback of fire and grasses may maintain forests, savannas and grasslands as alternative tree cover states. I also address how anthropogenic land use, including the introduction of livestock, may be affecting these dynamics, particularly in the neotropics, with consequences in terms of potential transitions in tree cover regimes.

I analyze the distribution of trees in the grasslands of subtropical South America, looking at what may determine current tree cover and change dynamics (Chapters 2 & 3). The results suggest that, in non-cultivated areas, the expansion of trees into grasslands is likely limited by fire, livestock and precipitation, and that livestock likely reduces fire frequency (Chapter 2). The analyses also suggest that in the Uruguayan Campos of southeastern South America, where fire frequency is low and livestock densities are high, a release in livestock density may cause a moderate expansion of forests into grasslands (Chapter 3). To understand the consequences of a potential transition to higher tree cover by increasing precipitation, I looked at the effects of tree cover in subtropical rangelands (Chapter 5). The results indicated that isolated trees can improve the forage quality and abundance of these rangelands, with potential benefits in terms of biodiversity and ecosystem services. Lastly, I analyzed correlational patterns relating livestock density to vegetation structure across the global tropics and subtropics (Chapter 4), in an attempt to generalize the findings of Chapter 2. The results indicate that extensive livestock systems reduce fire frequency and impact vegetation structure, maintaining savannas and grasslands with low tree cover, low fire frequency and a higher presence of shrubs and dwarf trees.

A comprehensive assessment of agriculture in lowlands of south Brazil: characterization and comparison of current and alternative concepts
Theisen, Giovani - \ 2017
University. Promotor(en): Niels Anten, co-promotor(en): Lammert Bastiaans. - Wageningen : Wageningen University - ISBN 9789463436380 - 234
cropping systems - farming systems - crop management - lowland areas - wetlands - pampas - brazil - intensification - sustainability - productivity - indicators - soil management - rice - flooded rice - oryza sativa - maize - zea mays - glycine max - cover crops - livestock - rotation - mixed farming - seedbed preparation - farm machinery - teeltsystemen - bedrijfssystemen - gewasteelt - laaglandgebieden - pampa's - brazilië - intensivering - duurzaamheid (sustainability) - productiviteit - indicatoren - bodembeheer - rijst - natte rijst - maïs - dekgewassen - vee - rotatie - gemengde landbouw - zaaibedbereiding - landbouwwerktuigen

Agriculture in the lowlands of south Brazil is of strategic importance at the national level, since it supplies around 80% of the rice consumed by the Brazilian population. In Rio Grande do Sul, the southernmost state in Brazil, three million hectares of lowlands are ready for grain-based agriculture. Of this area, about half is fallow, partly used for cattle grazing, and irrigated rice is the predominant crop, cultivated annually on 1.1 million ha. The remaining area is used for soybean and other crops. The predominant cropping system is a combination of irrigated rice and cattle. Over the last decades, rice yields have steadily increased, but this rise in yield level has to a large extent been obtained at the expense of a continuously higher use of external inputs. The recent introduction of soybean in rotation with rice has partially improved the system, but in most areas the situation is becoming incompatible with the modern demands for sustainability. This thesis presents a long-term study (2006-2015) of five cropping systems for lowlands. Next to monocrop rice and two rice-soybean rotations conducted in either conventional or minimum tillage, the experiment contained two novel systems based on large ridges, on which soybean and maize were combined with either cover crops or crop-livestock integration in winter. In these last systems, 8-m-wide ridges were built to avoid flooding, thus allowing for diversification of cash crops and the cultivation of cover crops or pastures in winter time, as well as the use of no-tillage. All systems were evaluated at process-level, including soil preparation, seeding, plant nutrition, pest management, irrigation, harvesting, transport and cattle management, as well as regarding their performance for the different dimensions of sustainability, particularly environment, land productivity, economics, energy-use and labour. Next to system assessment, two additional experiments were conducted for the evaluation of two specific technologies for soil management in these areas. Crop livestock integration on the ridge-based system offered the best balance between food production, environmental impact and economics. This system is well suited to be used in fields that are kept fallow, thereby enlarging the agricultural productivity of the lowlands. The additional experiments revealed that a knife-roller can successfully substitute plough-and-harrow for soil preparation after rice harvest, and that germination of weed seeds can be reduced if crop seeding is conducted at a lower speed or using a no-tillage seeder equipped with an improved cutting mechanism. Overall the results show that by using alternative cropping systems that allow for diversification and new methods of field management it is possible to simultaneously attain a larger agricultural production and improved sustainability in the lowlands.

Understanding relations between pastoralism and its changing natural environment
Tamou, Charles - \ 2017
University. Promotor(en): Imke de Boer, co-promotor(en): Simon Oosting; Raimon Ripoll Bosch; I. Youssao Aboudou Karim. - Wageningen : Wageningen University - ISBN 9789463431552 - 154
pastoralism - livestock - grazing - crop production - nature conservation - cattle breeds - environment - nature reserves - benin - pastoralisme - vee - begrazing - gewasproductie - natuurbescherming - rundveerassen - milieu - natuurreservaten

The competition for land has become an issue of major concern and cause of conflict, especially between pastoralists and crop farmers, but also between pastoralists and nature conservation institutions. The Biosphere Reserve of W in Benin Republic (WBR) and its surrounding lands are located in the agro-pastoral contact zone in West Africa, enabling competition for land, and affecting the relations between pastoralism and its environment. The general aim of this thesis, therefore, was to understand the relations between pastoralism and its changing natural environment. In terms of land use change, cropland area around WBR expanded, whereas grazing area reduced. Population growth and rising demand for food crops and cash crops were the indirect causes of this loss of grazing lands. Competing claims over land existed between crop farmers and pastoralists, among crop farmers, and among crop farmers, pastoralists, and the WBR authority due to past expropriation, unfair and incomplete implementation of the WBR regulations and the increasing shift of pastoral lifestyle to crop farming. In terms of effects of grazing on plant communities, highly grazed sites had more species diversity than lowly grazed sites. This suggests that the current level of grazing was not damaging plant communities’ diversity. Annual species dominated the surveyed vegetation, suggesting that restoration of grazing lands with perennials requires human intervention. Herding involves taking decisions and moving of livestock in search for feed. Herding decisions are based on traditional ecological knowledge (TEK) of soil, forage and livestock. Pastoralists identified five different soils, which they selected for herding at different times of the year. Perennial grasses were perceived of high nutritional quality, whereas annuals were of low nutritional quality. Afzelia africana had high perceived quality for milk production, whereas Khaya senegalensis had the highest perceived quality for meat production, health and strength. In decision making for herding, pastoralists used a holistic approach, combining TEK about soil, vegetation and livestock, in a structured and prioritised reasoning. Changes in the pastoral system can lead to changes in desired livestock traits, which may lead to loss of indigenous breeds. Keteeji was valued for its endurance and tolerance to trypanosomiasis, Bodeeji was highly valued for endurance and Gudali was perceived of high value for meat and milk production, but of low value for endurance. To deal with the changing and unfavourable conditions of their environment, pastoralists preferred cattle breeds performing well on adaptive traits i.e. withstanding hunger, intelligence, and withstanding disease. Our results suggest that pastoralism is under pressure and that its survival depends on policies. In the pessimistic scenario, i.e. without any change, pastoralists will use, likely, the stepping-out strategy in the future. In the optimistic scenario, two possible institutional interventions could help maintaining pastoralism in the region: payments for ecosystem services provided by pastoralism, and association of pastoralism with nature conservation. In practice, however, the implementation of these two interventions is very challenging, which implies an increasing vulnerability of pastoralists and pastoral lifestyle.

Sustainability of livestock production systems : a comparing conventional and organic livestock husbandry
Wagenberg, C.P.A. van; Haas, Y. de; Hogeveen, H. ; Krimpen, M.M. van; Meuwissen, M.P.M. ; Middelaar, C.E. van; Rodenburg, T.B. - \ 2016
Wageningen : Wageningen University & Research (Wageningen Economic Research report 2016-035) - ISBN 9789462577480 - 121
livestock - livestock farming - organic farming - europe - literature reviews - sustainable animal husbandry - farming systems - sustainability indicators - vee - veehouderij - biologische landbouw - europa - literatuuroverzichten - duurzame veehouderij - bedrijfssystemen - duurzaamheidsindicatoren
Sustainable livestock production systems are needed to feed the larger, more urban, richer and older world population in 2050. Quantitative information about the sustainability performance of existing livestock production systems can aid the debate of which actions could be developed and implemented. Strong points of conventional and organic dairy cattle, beef cattle, pig, laying hen, and broiler production systems were identified in peer-reviewed literature for a limited number of sustainability indicators within the subjects of economy, productivity, environment, animal welfare, and public health. This study aims to identify lessons learned for sustainable livestock production.
Towards improving the manure management chain
Hou, Yong - \ 2016
University. Promotor(en): Oene Oenema, co-promotor(en): Gerard Velthof. - Wageningen : Wageningen University - ISBN 9789462579620 - 215
manures - manure treatment - livestock - excretion - nitrogen - mitigation - methane - european union - mest - mestverwerking - vee - excretie - stikstof - mitigatie - methaan - europese unie

Animal manures are major sources of nutrients and organic matter, to be used to fertilize crops and improve soil quality. However, when not properly managed, these manures release considerable amounts of ammonia (NH3), nitrous oxide (N2O) and methane (CH4) into the air, and nitrogen (N) and phosphorus (P) to water bodies, which create a range of unwanted environment impacts. Nutrient losses from manure depend on the management activities and techniques used at different stages of the whole manure management chain, from animal feeding up to manure application to land. The trade-offs and co-benefits of emission mitigation measures and manure treatment technologies are as yet poorly understood, especially when taking the whole manure management chain into account. Moreover, the effects of combinations of measures and technologies have not been well analyzed, and analyses at national scales are lacking. The overall objective of this PhD thesis research is (i) to enhance the quantitative insight into the effects of emission mitigation measures and treatment technologies on emissions of NH3, N2O and CH4, and the recovery of N and P from animal manure in the whole management chain, and (ii) to explore the effects of combinations of measures and technologies to mitigate these emissions and to increase the N and P recovery.

In Chapter 2, methodologies for estimating N excretion factors for the main animal categories in member states of the European Union (EU) were reviewed. In Chapter 3, a transparent and uniform methodology for estimating annual feed use and N excretion per animal category for all countries of the EU-27 was developed, based on the energy and protein requirements of the animals and statistics of feed use and composition, animal number and productivity. In Chapter 4, firstly the impacts of a suite of NH3 mitigation measures on emissions of NH3, N2O and CH4 at individual stages of the manure management chain were analyzed by means of a meta-analysis of published data. Secondly, the overall impacts of alternative combinations of mitigation measures on emissions from the whole chain were evaluated through scenario analysis. Chapter 5 reports on an integrated assessment of the effects of manure treatment on NH3, N2O and CH4 emissions from manure management chains in EU-27 at the national level for 2010, using the model MITERRA-Europe. Whole-chain effects of implementing twelve treatment technologies in EU-27 on emissions and N and P recovery were further explored through scenario analyses. Chapter 6 reports on a survey conducted under various stakeholder groups with expertise in the domain of manure treatment in four European countries that have regions of high animal density. The survey addressed questions related to i) which factors facilitate and hinder the implementation of treatment technologies in practice, ii) which technologies have the most potential for successful adoption, and iii) how farm characteristics and the scale of the treatment operation affect priorities for adoption. The main conclusions of this PhD thesis are as follows:

In EU-27, the amounts of N and P in manure are as large as or larger than the total amounts of fertilizer N and P used annually. However, there is a huge spatial variation in manure production. Nutrient excretion factors per animal category also vary between countries, as a result of variations in feed use and animal productivity. Clearly, for accurate inventories of national emission there is a need for estimating nutrient excretion using country-specific feed use data.

Increasing the effectiveness of measures to mitigate NH3 and GHG emissions from animal manure requires proper combination of measures in the manure management chain. Lowering the dietary protein content in animal feed is an effective measure to reduce NH3 emissions and other N emissions at all stages of the manure management chain. Other measures may reduce emissions of a specific gas or emissions source, by which there is a risk of unwanted trade-offs in the manure management chain. Joint adoption of these measures with low-N feeding strategies and slurry acidification can greatly decrease the risk of pollution swapping.

Implementation of manure treatment is on average still limited in EU-27. Effects of manure treatment on NH3 and GHG emissions are therefore relatively small at EU level. Increasing the implementation of treatment technologies, including acidification, incineration and thermal drying, or optimized combinations of treatment technologies, can significantly contribute to achieving NH3 and GHG emission targets of EU environmental policies. Implementation of manure treatment technologies provides opportunities to improve the use of plant nutrients in manures, because of the release of manure products with different N/P ratios. Applying acidification technology and optimized combination of NH3 emission mitigation measures increase the N recovery from animal manure, and can decrease the demand of mineral fertilizers. However, some technologies decrease the N and P recovery and/or decrease the availability of the N and P in manure products to plants.

Implementation of manure treatment in practice is forced by the pressure from EU environmental regulations, and is hindered by financial barriers. To encourage the adoption of manure treatment, policies must be economically appealing to attract new adopters (farmers and industries). Long-term financial support schemes (e.g. subsidies) seem to be necessary, especially with the current low prices for fossil fuels. Outreach strategies are required to convey the knowledge to stakeholders from both the supply and the demand side, with respect to the economic, technical and environmental aspects of manure treatment technologies.

Assessing unconsciousness in livestock at slaughter
Verhoeven, Merel - \ 2016
University. Promotor(en): Bas Kemp, co-promotor(en): Marien Gerritzen; L.J. Hellebrekers. - Wageningen : Wageningen University - ISBN 9789462579064 - 187
livestock - slaughter - animal welfare - stunning - electroencephalograms - animal behaviour - consciousness - animal production - animal health - pigs - cattle - sheep - vee - slacht - dierenwelzijn - bedwelmen - elektro-encefalogrammen - diergedrag - bewustzijn (consciousness) - dierlijke productie - diergezondheid - varkens - rundvee - schapen

Assessing unconsciousness in livestock at different stages of the slaughter process is a legal requirement according to EU legislation. The assessment can be based on absence of readily observable indicators (behavioural indicators, physical signs and reflexes) or, under experimental conditions, by recording and subsequent assessment of brain activity as presented in an electroencephalogram (EEG). There is no consensus, however, to what extent different behavioural indicators, physical signs and reflexes accurately reflect unconsciousness. The aim of this thesis was to study the relationships between these readily observable indicators and EEG activity to provide information on 1. the exact point in time at which animals lose consciousness when subjected to different stunning and slaughter methods and 2. the validity of behavioural indicators, physical signs and reflexes used to assess unconsciousness at slaughter under commercial conditions. The results showed a large variation in time to loss of consciousness, based on EEG activity, both between stunning and slaughter procedures and amongst animals. Captive bolt stunned calves lost consciousness instantly following the stun. Loss of consciousness in pigs during CO2 stunning varied from 21 to 61 s after start of the exposure. An increased CO2 concentration decreased the time to loss of consciousness. Times to loss of consciousness in sheep slaughtered without stunning varied from 6 to 24 s. In cattle slaughtered without stunning, times to loss of consciousness varied from 14 s up to over two minutes. Following captive bolt stunning in calves, absence of reflexes indicated unconsciousness. When consciousness was lost gradually (e.g. CO2 stunning and non-stunned slaughter) none of the readily observable indicators could identify the exact point in time at which animals lost consciousness. Absence of rhythmic breathing, corneal reflex- and eyelid reflex were valid indicators of unconsciousness following CO2 stunning and non-stunned slaughter, but these indicators were quite conservative as they were initially absent long after EEG activity indicated unconsciousness. When presence of these indicators would require (re)stunning, many animals will have to be (re)stunned. The results also showed that under full commercial conditions, stunning effectiveness must be closely monitored by slaughter plant employees, since risks for stun failures are higher under commercial conditions compared to experimental conditions.

ESBL Evaluation framework
Bondt, N. ; Asseldonk, M.A.P.M. van; Bergevoet, R.H.M. - \ 2016
The Hague : LEI Wageningen UR (Report / LEI Wageningen UR 2016-020) - ISBN 9789462578517 - 45 p.
extended spectrum beta-lactamases - livestock - epidemiology - animal welfare - animal health - public health - food safety - risk management - verbreed spectrum bèta-lactamases - vee - epidemiologie - dierenwelzijn - diergezondheid - volksgezondheid - voedselveiligheid - risicobeheersing
Extended-spectrum bèta-lactamases (ESBL)-producing bacteria have become increasingly common in animals and humans. The goal of the presented ESBL evaluation framework is to help policy makers to evaluate the effectiveness of possible interventions aimed to reduce ESBL levels in livestock. An objective-driven ESBL policy approach (i.e., setting more clear and stringent objectives, for example maximum ESBL prevalence on national level) is preferable since much is unknown about other potential relevant measures and moreover the accountability of individual agents is hampered, which are both requisites for a measure-driven policy approach. In addition, for the nearby future, an additional measure is to extend the ban on some other antibiotics that are related to ESBLs.
Is sustainable development of semi-subsistence mixed crop-livestock systems possible? : an integrated assessment of Machakos, Kenya
Valdivia, R.O. - \ 2016
University. Promotor(en): Tammo Bult, co-promotor(en): J. Antle; Jetse Stoorvogel. - Wageningen : Wageningen University - ISBN 9789462578272 - 233 p.
sustainable development - development economics - livestock - cash crops - agriculture - mixed farming - development policy - policy - rural areas - poverty - farming - kenya - east africa - duurzame ontwikkeling - ontwikkelingseconomie - vee - marktgewassen - landbouw - gemengde landbouw - ontwikkelingsbeleid - beleid - platteland - armoede - landbouw bedrijven - oost-afrika

Sub-Saharan Africa countries face the challenge of reducing rural poverty and reversing the declining trends of agricultural productivity and the high levels of soil nutrient depletion. Despite of numerous efforts and investments, high levels of poverty and resource degradation persist in African agriculture. The Millennium Development Goals Report (MDGR) states that the majority of people living below the poverty line of $1.25 a day belong to Sub-Saharan Africa (SSA) and South Asia. About two thirds of the global rural population lives in mixed crop-livestock systems (CLS), typical of SSA, where interactions between crops and livestock activities are important for the subsistence of smallholders. CLS are characterized by high degree of biophysical and economic heterogeneity, complex and diversified production system that frequently involves a combination of several subsistence and cash crops and livestock. Increasing crop productivity is clearly a key element to improve living standards and to take these people out of poverty. However, agricultural productivity in most of SSA has been stagnant or increased slowly. In addition, the likely negative impacts of climate change on agriculture have accentuated the vulnerability of smallholders.

The international research community has once more the eyes on SSA with the recently proposed post-2015 MDGs, the Sustainable Development Goals that emphasize the need to achieve sustainable development globally by 2030 by promoting economic development, environmental sustainability, good governance and social inclusion. Governments and scientists are making considerable efforts to develop strategies that include structural transformations of the different sectors of the economy in search of the recipe to achieve the SDGs. Most of these strategies are based on policy and technology interventions that seek to achieve the “win-win” outcomes and move from the usual “tradeoffs” between poverty-productivity-sustainability to synergies. A key message of this thesis is that achieving the goal of sustainable development in semi-subsistence African agriculture will require better understanding of the poverty-productivity-sustainability puzzle: why high poverty and resource degradation levels persist in African agriculture. I hypothesize that the answer to this puzzle lies, at least in part, in understanding and appropriately analyzing key features of semi-subsistence crop-livestock systems (CLS) typical of Sub-Saharan Africa. The complexity and diversity of CLS often constrain the ability of policy or technology interventions to achieve a “win-win” outcome of simultaneously reducing poverty while increasing productivity sustainably (i.e., avoiding soil nutrient losses).

This thesis focuses on the Machakos Region in Kenya. Machakos has been the center of many studies looking at soil fertility issues and its implications for poverty and food security, including the well-known study by Tiffen et al. (1994). Recently, the Government of Kenya developed the Kenya Vision 2030, a long-term development strategy designed to guide the country to meet the 2015 MDGs and beyond. The agricultural sector is recognized as one of the economic actors that can lead to reduce poverty if appropriate policies are in place. For the Vision 2030, the key is to improve smallholder productivity and promote non-farm opportunities. The Vision 2030 was used to assess if the implementation of some of the proposed plans and policies can lead to a sustainable agriculture for smallholders in the Machakos region.

This thesis describes and uses the Tradeoff Analysis Model (TOA), an integrated modeling approach designed to deal with the complexities associated to production systems such as the CLS and at the same time, quantify economic and sustainability indicators for policy tradeoff analysis (e.g., poverty indexes and measures of sustainability). The TOA was linked to Representative Agricultural Pathways and Scenarios to represent different future socio-economic scenarios (based on the Vision 2030) to assess the impacts of policy interventions aimed to move agricultural systems towards meeting sustainable development goals.

One important finding is that the complex behavior of CLS has important implications for the effectiveness of policy interventions. The Machakos analysis provides important findings regarding the implementation and effectiveness of policy interventions addressing poverty and sustainability in Africa and other parts of the developing world. The analysis shows that policy interventions tend to result in much larger benefits for better-endowed farms, implying that farm heterogeneity results in differential policy impacts and that resilience of agricultural systems is likely to be highly variable and strongly associated with heterogeneity in bio-physical and economic conditions. The results shows that a combination of these interventions and strategies, based on the GoK Vision 2030 and the Machakos County plans, could solve the poverty-productivity-sustainability puzzle in this region. The pathway from tradeoffs to synergies (win-win) seems to be feasible if these interventions and strategies are well implemented, however the analysis also shows that some villages may respond better to these strategies than others. The analysis suggests that these interventions may actually benefit most the areas with better initial endowments of soils and climate.

The analysis also suggested that prices (e.g., maize price) play a key role in the assessment of policy interventions. There is an increasing recognition that analysis of economic and environmental outcomes of agricultural production systems requires a bottom-up linkage from the farm to market, as well as top-down linkage from market to farm. Hence, a two-way linkage between the TOA model and a partial equilibrium market model (ME) was developed. The TOA model links site-specific bio-physical process models and economic decision models, and aggregate economic and environmental outcomes to a regional scale, but treats prices as exogenous. The resulting TOA-ME allows the effects of site-specific interactions at the farm scale to be aggregated and used to determine market equilibrium. This in turn, can be linked back to the underlying spatial distribution of economic and environmental outcomes at market equilibrium quantities and prices. The results suggest that market equilibrium is likely to be important in the analysis of agricultural systems in developing countries where product and input markets are not well integrated, and therefore, local supply determines local prices (e.g., high transport costs may cause farm-gate prices be set locally) or where market supply schedules are driven not only by prices but also by changes in farm characteristics in response to policy changes, environmental conditions or socio-economic conditions. The results suggest that the market equilibrium price associated to a policy intervention could be substantially different than the prices observed without the market equilibrium analysis, and consequently could play an important role in evaluating the impacts of policy or technology interventions.

As mentioned above, climate change poses a long-term threat for rural households in vulnerable regions like Sub-Saharan Africa. Policy and technology interventions can have different impacts under climate change conditions. In this thesis the likely economic and environmental impacts of climate change and adaptations on the agricultural production systems of Machakos are analyzed.

Climate change impact assessment studies have moved towards the use of more integrated approaches and the use of scenarios to deal with the uncertainty of future condition. However, several studies fall short of adequately incorporating adaptation in the analysis, they also fall short of adequately assessing distributional economic and environmental impacts. Similarly, climate change is likely to change patterns of supply and demand of commodities with a consequent change in prices that could play an important role in designing policies at regional, national and international levels. Therefore, a market equilibrium model should also be incorporated in the analysis to assess how markets react to changing prices due to shifts in supply and demand of commodities. The TOA-ME was used to incorporate the elements mentioned above to assess the impacts of climate change. Using data from 5 Global Circulation Models (GCMs) with three emission scenarios (SRES, 2000) to estimate the climate change projections, these projections were used to perturb weather data used by a crop simulation model to estimate the productivity effects of climate change. Land use change and impacts on poverty and nutrient depletion at the market equilibrium were then assessed using the TOA-ME model.

The simulation was carried out for three scenarios, which are a combination of socio-economic and climate change scenarios: a baseline scenario that represents current socio-economic conditions and climate conditions, a climate change and current socio-economic scenarios (i.e., future climate change with no policy or technology intervention), and a climate change and future socio economic conditions which are a consequence of rural development policies.

Our findings show that in this particular case, the changes on precipitation, temperature and solar radiation do not show a significant difference among the selected emission scenarios. However, the variability is significant across GCMs. The effects of climate change on crop productivity are negative on average. These results show that policy and technology interventions are needed to reduce this region’s vulnerability. Furthermore, the socio-economic scenarios based on policy and technology interventions presented in the case study would be effective to offset the negative effect of climate change on the sustainability (economical and environmental) of the system across a range of possible climate outcomes represented by different GCMs. Finally, the results show that ignoring market equilibrium analysis can lead to biased results and incorrect information for policy making, in particular for the scenario based on policy and technology interventions.

One of the major conclusions of the thesis are that policy interventions aimed to deal with poverty and sustainability can have unintended consequences if they are not accompanied by a set of policy strategies and investments. For example, increasing the maize price can result in substitution from subsistence crops to maize, without much increase in nutrient inputs, thus increasing soil nutrient losses. The analysis shows that improving soil nutrient balances by increasing fertilizer and manure use is critically important, but is not enough to move the system to a sustainable path.

There is no one factor that can reverse the negative nutrient balances and move the system towards sustainability. Rather, a broad-based strategy is required that stimulates rural development, increases farm size to a sustainable level, and also reduces distortions and inefficiencies in input and output markets that tend to discourage the use of sustainable practices. The Machakos case shows that a combination of these interventions and strategies, based on the GoK Vision 2030 and the Machakos County plans, could solve the poverty-productivity-sustainability puzzle in this region.

Methodology for estimating emissions from agriculture in the Netherlands. : Calculations of CH4, NH3, N2O, NOx, PM10, PM2.5 and CO2 with the National Emission Model for Agriculture (NEMA)
Vonk, J. ; Bannink, A. ; Bruggen, C. van; Groenestein, C.M. ; Huijsmans, J.F.M. ; Kolk, J.W.H. van der; Luesink, H.H. ; Oude Voshaar, S.V. ; Sluis, S.M. ; Velthof, G.L. - \ 2016
Wageningen : Statutory Research Tasks Unit for Nature & the Environment (WOt-technical report 53) - 164 p.
air pollutants, greenhouse gases, livestock, crops, animal housing, manure storage, manure application, inorganic fertilizer, enteric fermentation, manure management, agricultural soils, liming, NIR, CRF, IIR, NFR - landbouw - gewassen - landbouwgronden - vee - huisvesting, dieren - dierlijke meststoffen - rundveemest - mestverwerking - begrazing - broeikasgassen - luchtverontreinigende stoffen - emissie - ammoniakemissie - kooldioxide - methaan - anorganische meststoffen - fermentatie - bekalking - nederland - compost - rioolslib - teelt - oogstresten - rijp worden - agriculture - crops - agricultural soils - livestock - animal housing - animal manures - cattle manure - manure treatment - grazing - greenhouse gases - air pollutants - emission - ammonia emission - carbon dioxide - methane - inorganic fertilizers - fermentation - liming - netherlands - composts - sewage sludge - cultivation - crop residues - ripening
The National Emission Model for Agriculture (NEMA) is used to calculate emissions to air from agricultural activities in the Netherlands on a national scale. Emissions of ammonia (NH3) and other N-compounds (NOx and N2O) from animal housing, manure storage, manure application and grazing are assessed using a Total Ammoniacal Nitrogen (TAN) flow model. Furthermore, emissions from application of inorganic N-fertilizer, compost and sewage sludge, cultivation of organic soils, crop residues, and ripening of crops are calculated. NEMA is also used to estimate emissions of methane (CH4) from enteric fermentation and manure management, particulate matter (PM) from manure management and agricultural soils, and carbon dioxide
(CO2) from liming. Emissions are calculated in accordance with international guidance criteria and reported in an annual Informative Inventory Report (IIR; for air pollutants) and National Inventory Report (NIR; for greenhouse gases). This methodology report describes the outline and backgrounds of the emission
calculations with NEMA
Feed sources for livestock : recycling towards a green planet
Zanten, H.H.E. van - \ 2016
University. Promotor(en): Imke de Boer, co-promotor(en): Paul Bikker; Bastiaan Meerburg. - Wageningen : Wageningen University - ISBN 9789462578050 - 251 p.
cum laude - livestock - livestock feeding - feeds - resources - food wastes - leftovers - recycling - greenhouse gases - environmental impact - innovations - sustainable animal husbandry - animal production - vee - veevoeding - voer - hulpbronnen - voedselafval - etensresten - broeikasgassen - milieueffect - innovaties - duurzame veehouderij - dierlijke productie

Production of food has re-emerged at the top of the global political agenda, driven by two contemporary challenges: the challenge to produce enough nutritious food to feed a growing and more prosperous human population, and the challenge to produce this food in an environmentally sustainable way. Current levels of production of especially animal-source food (ASF), pose severe pressure on the environment via their emissions to air, water, and soil; and their use of scarce resources, such as land, water, and fossil energy. The livestock sector, for example, is responsible for about 15% of the global anthropogenic emissions of greenhouse gases and uses about 70% of global agricultural land.

Many proposed mitigation strategies to feed the world sustainably, therefore, focus primarily on reducing the environmental impact of the livestock sector, so-called production-side strategies. Other strategies focus on changing consumption patterns by reducing consumption of ASF, or on shifting from ASF with a higher environmental impact (e.g. beef) to ASF with a lower environmental impact (e.g. pork or chicken), so called consumption-side strategies.

Most of the environmental impact of production of ASF is related to production of feed. One production-side strategy to reduce the environmental impact is the use of products that humans cannot or do not want to eat, such as co-products, food-waste, and biomass from marginal lands for livestock feed (referred to as ‘leftover streams’ in this thesis). This strategy is effective, because feeding leftover streams to livestock transforms an inedible food stream into high-quality food products, such as meat, milk, and eggs.

Two production-side strategies that use leftover streams as livestock feed were explored in this thesis: replacing soybean meal (SBM) in diets of growing pigs with either rapeseed meal (RSM) or with waste-fed larvae meal. Replacing SBM with RSM in growing-pig diets was assessed because RSM became increasingly available following an increase in bio-energy production in the EU. In this strategy, therefore, the RSM content in pig diets increased at the expense of SBM. SBM is an ingredient associated with a high environmental impact. It was expected, therefore, that replacing SBM with RSM in pig diets would lead to a decrease in the environmental impact of pork production. Replacing SBM with waste-fed larvae meal was assessed because recent developments show the environmental benefits of rearing insects as livestock feed. Insects have a low feed conversion ratio (kg feed/kg product) and can be consumed completely, without residual materials, such as bones or feathers. The nutritional value of insects is high, especially as a protein source for livestock. Insect-based feed products, therefore, can replace conventional feed ingredients, such as SBM. Altogether this strategy suggests that waste-fed larvae meal might become an important alternative feed source in the future.

To gain insight into the status quo of the environmental impact of both mitigation strategies, replacing SBM with RSM or with waste-fed insects, we first used the attributional life cycle assessment (ALCA) method. Based on the ALCA method, results showed that each mitigation strategy was promising. Replacing SBM with RSM in growing pig diets hardly changed either global warming potential (GWP) or energy use (EU), but decreased land use (LU) up to 16% per kg body weight gain. As expected, feed production had the largest environmental impact, responsible for about 50% of the GWP, 60% of the EU, and 77% of the total LU. Feed production in combination with feed intake, were the most sensitive parameters; a small change in both these two parameters changed the results. Replacing SBM with waste-fed larvae meal in growing-pig diets showed that EU hardly changed, but GWP (29%) and LU (54%) decreased per kg body weight gain. Based on ALCA results, each mitigation strategy, therefore, seems to offer potential to reduce the environmental impact of pork production. An ALCA, however, has two disadvantages: it does not account for product-packages and it does not consider feed-food competition.

The first disadvantage of ALCA was that the complexity of dealing with product-packages is not fully considered. ‘Product-package’ refers to a multiple-output situation. During the processing of sugar beet, for example, beet-pulp and molasses are produced in addition to sugar. Sugar, beet-pulp, and molasses together form a ‘package of products’ because they cannot be produced independently from each other. An ALCA does not account for the fact that the production volume of the co-product(s) depends on the demand for the determining product (e.g. sugar), which results in the limited availability of co-products. Increasing the use of co-products in animal feed, consequently, results in reducing use of a co-product in another sector, requiring them to be replaced with a different product. The environmental impact of increasing the use of a co-product or food-waste, therefore, depends on the net environmental impact. The net environmental impact refers to the environmental benefits of using the product in its new application minus the environmental cost of replacing the product in its old application.

A consequential theoretical framework was developed to account for product-packages. The results, based on the consequential framework, contradicted standard ALCA results. The consequential LCA (CLCA) method we used for replacing SBM with RSM showed an increased GWP (up to 15%), EU (up to 12%), and LU (up to 10%) per kg body weight gain. Moreover, this CLCA method showed that replacing SBM with waste-fed larvae meal increased GWP (60%) and EU (90%), but decreased LU (73%) per kg body weight gain.

Accounting for product-packages increased the net environmental impact of each strategy, replacing SBM with RSM or with waste-fed larvae meal. The difference in results between ALCA and CLCA was especially large in the strategy with waste-fed larvae meal. The difference was caused mainly by the use of food-waste. Food-waste fed to larvae was used initially to produce bio-energy via anaerobic digestion. In CLCA, the environmental impact related to replacing the bio-energy function of food-waste with fossil-energy was included. The net environmental impact became negative, because environmental benefits of replacing SBM with waste-fed larvae meal were less than environmental costs related to the marginal energy source, i.e. fossil energy, replacing the bio-energy. Results of the indirect environmental impact, however, are situation specific: if the marginal energy source were wind or solar energy, the net environmental impact of using waste-fed larvae meal might be positive. Waste-fed larvae meal, therefore, appears to be an interesting mitigation strategy only when energy from wind and solar energy are used more dominantly than energy from fossil sources.

If results were based solely on ALCA, then these potentially negative impacts would have been overlooked. Consideration of the environmental consequences of product-packaging, therefore, is essential to determine total environmental costs. If policy makers or the feed industry want to assess the net environmental impact of a potential mitigation strategy, then we recommend to perform a CLCA instead of an ALCA. The framework developed in this thesis can be used to perform such an assessment.

The second disadvantage of an LCA was that it does not take into account feed-food competition, e.g. competition for land between humans and animals. Most LCA studies focus on the total amount of land required to produce one kg ASF. LCA studies do not account for competition for land between humans and animals, or so-called feed-food competition. In other words, they do not include, differences in the consumption of human-edible products by various livestock species or differences in the suitability of land used for feed production as land to cultivate food-crops directly. Given the global constraints on land, it is more efficient to grow food directly for human consumption rather than for livestock. To address the contribution of livestock to a future sustainable food supply, a measure for land use efficiency was developed, called the land use ratio (LUR). The LUR accounts for plant productivity, efficiency of converting human-inedible feed into ASF, and suitability of land for crop cultivation. The LUR also has a life-cycle perspective.

Results of the LUR illustrated that dairy cows on sandy soil, laying hens, and pig production systems in the Netherlands have a LUR >1.0. In terms of protein produced per m2, therefore, it is more efficient to use these soils for livestock production to produce crops for direct human consumption than to produce feed for livestock. Only dairy cows on peat soil produce human digestible protein (HDP) more efficiently than crops do, because peat is not suitable for crop production. The LUR allows identification of livestock production systems that are able to produce HDP more efficiently than crops do. Livestock systems with a LUR<1.0, such as dairy on peat, have an important role to play in future sustainable nutrition supply.

Results of the LUR showed that livestock production systems using mainly co-products, food-waste, and biomass from marginal land, can produce human digestible protein more efficiently than crop production systems do. The availability of those leftover streams, however, is limited and, therefore, the amount of ASF produced based only on leftover streams is also limited. Because LUR is a ratio, LUR results do not give an indication of how much ASF can be produced based on livestock systems that feed mainly on leftover streams.

The third, and last, mitigation strategy, therefore, focused on the amount of ASF that can be consumed by humans, when livestock are fed only on leftover steams, also referred to as “default livestock”. The calculation of the amount of ASF was based on the assumption that a vegan diet was consumed in principle. The resulting co-products and food-waste were fed to pigs and, biomass from grazing land was fed to ruminants. Results showed that in total 21 g animal source protein per person per day could be produced by feeding livestock entirely on leftovers.

Considering feed-food crops and feeding food-waste made an important contribution to the 21 g of protein that could be produced from default livestock. Considering feed-food crops implies that choices have to be made between different crops, based on their contribution to feed and food production. Oil production from soy cultivation, for example, resulted in the co-product SBM. Results showed that considering feed-food crops can affect the final protein production from pork. The practice of feeding food-waste to livestock is currently prohibited due to problems of food safety but the practice shows potential in extensively reducing the environmental impact of livestock production. Considering feed-food crops and feeding food-waste are examples of mitigation strategies that currently can be implemented to reduce further the environmental impact of the livestock sector.

On average, it is recommended to consume about 57 g of protein from ASF or plant-origin per person per day. Only ASF from default livestock does not fulfil the current global protein consumption of 32 g per person per day, but about one third of the protein each person needs can be produced without any competition for land between feed and food production. To feed the world more sustainably, by requiring livestock production systems with a LUR <1.0, however, a paradigm shift is needed. Global average consumption of ASF should decrease to about 21 g of protein per person per day. Innovations are needed, moreover, to overcome problems of food safety and technical concerns related to collecting the leftover streams. This applies, in particular to food-waste, which is currently unused in livestock production but which presents a valuable strategy in mitigating environmental impacts caused by livestock production. Livestock systems should change their focus, furthermore, from increasing productivity per animal towards increasing protein production for humans per ha. By using leftover streams optimally, the livestock sector is able to produce a crucial amount of protein, while still avoiding competition for land between feed and food crops. Livestock, therefore, can make an important contribution to the future nutrition supply.

Estimating host genetic effects on susceptibility and infectivity to infectious diseases and their contribution to response to selection
Anche, M.T. - \ 2016
University. Promotor(en): Mart de Jong, co-promotor(en): Piter Bijma. - Wageningen : Wageningen University - ISBN 9789462577442 - 185 p.
livestock - hosts - genetic effects - susceptibility - infectivity - infectious diseases - breeding value - heritability - epidemics - vee - gastheren (dieren, mensen, planten) - genetische effecten - vatbaarheid - infectiviteit - infectieziekten - fokwaarde - epidemieën

Mahlet Teka Anche. (2016). Estimating host genetic effects on susceptibility and infectivity to infectious diseases and their contribution to response to selection. PhD thesis, Wageningen University, the Netherlands

Genetic approaches aiming to reduce the prevalence of an infection in a population usually focus on improving host susceptibility to an infection. The prevalence of an infection, however, is also affected by the infectivity of individuals. Studies reported that there exists among host (genetic/phenotypic) variation in susceptibility and infectivity to infectious diseases. The effect of host genetic variation in susceptibility and infectivity on the prevalence and risk of an infection is usually measured by the value of the basic reproduction ratio, R0. R0 is an important epidemiological parameter that determines the risk and prevalence of an infection. It has a threshold value of 1, where major disease outbreak can occur when R0 > 1 and the disease will die out when R0 < 1. Due to this threshold property, genetic improvements aiming to reduce the prevalence of an infection should focus on reducing R0 to a value below 1. The overall aim of this thesis was to develop methodologies that allow us to investigate the genetic effects of host susceptibility and infectivity on the prevalence of an infection, which is measured by the value of R0. Moreover, we also aim to investigating the effect of relatedness among groupmates on the utilization of among host genetic variation in susceptibility and infectivity so as to reduce the prevalence of infectious diseases. The theory of direct-indirect genetic effects and epidemiological concepts were combined to develop methodologies. In addition, a simulation study was performed to validate the methodologies developed and examine the effect of relatedness on the utilization of genetic variation in susceptibility and infectivity. It was shown that an individual’s genetic effect on its susceptibility and infectivity affect the prevalence of an infection and that an individual’s breeding value for R0 can be defined as a function of its own allele frequencies for susceptibility and infectivity and of population average susceptibility and infectivity. Moreover, simulation results show that, not only an individual’s infectivity but also an individual’s susceptibility represents an indirect genetic effect on the disease status of individuals and on the prevalence of an infection in a population. It was shown that having related groupmates allows breeders to utilize the genetic variation in susceptibility and infectivity, so as to reduce the prevalence of an infection.

Breeding against infectious diseases in animals
Rashidi, H. - \ 2016
University. Promotor(en): Johan van Arendonk, co-promotor(en): Herman Mulder; P.K. Mathur. - Wageningen University - ISBN 9789462576452 - 179 p.
livestock - infectious diseases - animal breeding - selective breeding - disease resistance - tolerance - genetic variation - breeding value - genetic correlation - traits - genomics - animal genetics - vee - infectieziekten - dierveredeling - selectief fokken - ziekteresistentie - tolerantie - genetische variatie - fokwaarde - genetische correlatie - kenmerken - genomica - diergenetica

Infectious diseases in farm animals are of major concern because of animal welfare, production costs, and public health. Farms undergo huge economic losses due to infectious disease. The costs of infections in farm animals are mainly due to production losses, treatment of infected animals, and disease control strategies. Control strategies, however, are not always successful. Selective breeding for the animals that can mount a defence against infection could therefore be a promising approach. Defensive ability of an animal has two main mechanisms: resistance (ability to control the pathogen burden) and tolerance (ability to maintain performance when pathogen burden increases). When it is difficult to distinguish between resistance and tolerance, defensive ability is measured as resilience that is the ability to maintain performance during a disease outbreak regardless of pathogen burden. Studies have focused on the genetics of resistance and resilience with little known about the genetics of tolerance and its relationship with resistance and resilience. The objectives of this thesis were to: 1) estimate the genetic variation in resistance, tolerance, and resilience to infection in order to assess the amenability of these traits for selective breeding in farm animals, 2) estimate the genetic correlation between resistance, tolerance and resilience and 3) detect genomic regions associated with resistance, tolerance, and resilience.

In chapter 2, we studied the variation among sows in response to porcine reproductive and respiratory syndrome (PRRS). First a statistical method was developed to detect PRRS outbreaks based on reproduction records of sows. The method showed a high sensitivity (78%) for disease phases. Then the variation of sows in response to PRRS was quantified using 2 models on the traits number of piglets born alive (NBA) and number of piglets born dead (LOSS): 1) bivariate model considering the trait in healthy and disease phases as different traits, and 2) reaction norm model modelling the response of sows as a linear regression of the trait on herd-year-week estimates of NBA. Trait correlations between healthy and disease phases deviated from unity (0.57±0.13 – 0.87±0.18). The repeatabilities ranged from 0.07±0.027 to 0.16±0.005. The reaction norm model had higher predictive ability in disease phase compared to the bivariate model.

In chapter 3 we studied 1) the genetic variation in resistance and tolerance of sheep to gastrointestinal nematode infection and 2) the genetic correlation between resistance and tolerance. Sire models on faecal nematode egg count (FEC), IgA, and pepsinogen were used to study the genetic variation in resistance. Heritability for resistance traits ranged from 0.19±0.10 to 0.59±0.20. A random regression model was used to study the reaction norm of sheep body weight on FEC as an estimate of tolerance to nematode infection. We observed a significant genetic variance in tolerance (P<0.05). Finally a bivariate model was used to study the genetic correlation between resistance and tolerance. We observed a negative genetic correlation (-0.63±0.25) between resistance and tolerance.

In chapter 4, we studied the response to selection in resistance and tolerance when using estimated breeding values for resilience. We used Monte Carlo simulation to generate 100 half-sib families with known breeding values for resistance (pathogen burden) and tolerance. We used selection index theory to predict response to selection for resistance and tolerance: 1) when pathogen burden is known and selection is based on true breeding values for resistance and tolerance and 2) when pathogen burden is unknown and selection is based on estimated breeding values for resilience. Using EBV for resilience in absence of records for pathogen burden resulted in favourable responses in resistance and tolerance to infections, with more emphasis on tolerance than on resistance. However, more genetic gain in resistance and tolerance could be achieved when pathogen burden was known.

In chapter 5 we studied genomics regions associated with resistance, resilience, and tolerance to PRRS. Resistance was modelled as sire effect on area under the PRRS viremia curve up to 14 days post infection (AUC14). Resilience was modelled as sire effects on daily growth of pigs up to 28 days post infection (ADG28). Tolerance was modelled as the sire effect on the regression of ADG28 on AUC14. We identified a major genomics region on chromosome 4 associated with resistance and resilience to PRRS. We also identified genomics regions on chromosome 1 associated with tolerance to PRRS.

In the general discussion (chapter 6) I discussed: 1) response to infection as a special case of genotype by environment interaction, 2) random regression model as a statistical tool for studying response to disease, 3) advantages and requirements of random regression models, and 4) selective breeding of farm animals for resistance, tolerance, and resilience to infections. I concluded that random regression is a powerful approach to estimate response to infection in animals. If the adequate amount of data is available random regression model could estimate breeding values of animals more accurately compared to other models. I also concluded that before including resistance and tolerance into breeding programs, breeders should make sure about the added values of including these traits on genetic progress. Selective breeding for resilience could be a pragmatic approach to simultaneously improve resistance and tolerance.

Production of mineral concentrates from animal manure using reverse osmosis : monitoring of pilot plants in 2012-2014
Hoeksma, P. ; Buisonjé, F.E. de - \ 2015
Wageningen : Wageningen UR Livestock Research (Livestock Research report 858) - 21
livestock - animal manures - manure treatment - slurries - reverse osmosis - separation - vee - dierlijke meststoffen - mestverwerking - drijfmest - omgekeerde osmose - scheiding
From 2009 to 2011 the agricultural, economic and environmental effects of the production and use of mineral concentrates, produced from animal slurry, were studied. Part of the study was the monitoring of the 8 participating full-scale (pilot) plants to assess the chemical composition of the half products and the end products of the process. In 2012 - 2014 the monitoring programme was continued with 9 pilot plants. In this programme additional data from the pilot plants were collected on the chemical composition of the raw slurry and the end products. Samples from these process streams were analysed on dry matter, volatile solids and the main nutrients N, P and K. The raw material of 8 pilot plants was pig slurry only. One plant used effluent from a biogas plant mixed with pig slurry as a feedstock.
Snelle meettechnieken voor nutriëntenbenutting bij landbouwhuisdieren
Vrolijk, M. ; Goselink, R.M.A. ; Veldkamp, T. - \ 2015
Wageningen : Wageningen UR Livestock Research (Livestock Research rapport 902) - 43
vee - veevoeding - nutriëntengebruiksefficiëntie - voedingsstoffenopname (mens en dier) - meettechnieken - voedingsfysiologie - livestock - livestock feeding - nutrient use efficiency - nutrient intake - measurement techniques - nutrition physiology
Efficient feeding of animals in livestock production deserves constant attention. Feed is input for milk, meat and egg production. It is a challenge to use nutrients as efficiently as possible, and produce ‘more with less’. Feeding the animals at their requirements can be improved if the effects of nutrient intake can be measured within a short time. This project made an overview of possible ‘rapid measuring techniques’ to be used in the near future. Each technique was scored for relevance, technical feasibility, practical application and the investment needed for development (time and money). From an expert workshop, measuring by means of sensor boluses or fluorescent markers as well as manure analysis, were defined as most promising for future research and practice.
Biological processes induced by ZnO, Amoxicillin, Rye and Fructooligosaccharides in cultured Intestinal Porcine Epithelial Cells : VDI-4; In-vitro tests 2013-2014
Hulst, M.M. ; Hoekman, A.J.W. ; Wijers, I. ; Schokker, D. ; Smits, M.A. - \ 2015
Wageningen : Wageningen UR Livestock Research (Livestock Research report 882) - 42
in vitro - bioassays - epithelium - livestock - feed additives - genes - immunology - biotesten - epitheel - vee - voedertoevoegingen - genen - immunologie
The objective of this study was to develop an in-vitro bioassay using cultured Intestinal Porcine Epithelial Cells (IPEC-J2) and evaluate the capability of this assay to predict enterocyte-specific physiological and immunological processes induced by nutrients/additives in the intestines of farm animals. Responses to five nutrients/feed-additives, similar to those studied in animal trials, performed in the Feed4Foodure framework, were measured by gene expression analysis of IPEC-J2 cells either under stressed (Salmonella) or non-stressed conditions. Response genes were analysed using bioinformatics web-tools in order to identify dominant biological processes induced by these nutrients/feed-additives and to predict key-genes/proteins important for regulation of these biological proc
Roaming livestock distribution, densities and population estimates for St. Eustatius, 2013
Debrot, A.O. ; Hazenbosch, J.C.J. ; Piontek, S. ; Kraft, C. ; Belle, J. van; Strijkstra, A. - \ 2015
Den Helder : IMARES (Report / IMARES Wageningen UR C088/15) - 27
sint eustatius - vee - wilde dieren - populatiedichtheid - herkauwers - erosie - caribische eilanden - milieuafbraak - livestock - wild animals - population density - ruminants - erosion - caribbean islands - environmental degradation
The problem of roaming livestock is a major impediment to agricultural development and nature conservation on St. Eustatius, as it also typically is on other islands in the region. In support of a government-led culling program, we here conducted a baseline study of livestock abundance and distribution on the island in the final quarter of 2013.
Groepskraamsysteem: analyse van de ontwikkeling van zeugen, biggen en vleesvarkens
Peet-Schwering, C.M.C. van der; Nieuwamerongen, S.E. van; Bolhuis, J.E. ; Troquet, L.M.P. ; Hoofs, A.I.J. ; Soede, N.M. - \ 2015
Wageningen : Wageningen UR Livestock Research (Livestock Research rapport 880)
zeugen - biggen - varkenshouderij - varkensfokkerij - varkens - spenen - kraamhokken - varkensstallen - diergedrag - prestatieniveau - biggen werpen - vee - dierenwelzijn - groepshuisvesting - sows - piglets - pig farming - pig breeding - pigs - weaning - farrowing pens - pig housing - animal behaviour - performance - farrowing - livestock - animal welfare - group housing
Op VIC Sterksel is de ontwikkeling (groei, voeropname, gezondheid, sociaal gedrag, spelgedrag en beschadigend gedrag) van biggen die opgegroeid zijn in een groepskraamsysteem en na spenen gehuisvest zijn in een verrijkt hok in een groep van 40 biggen vergeleken met de ontwikkeling van biggen die opgegroeid zijn in een traditioneel kraamhok en na spenen als toom bij elkaar zijn gehouden in een gangbaar hok met 10 biggen. Bij opleg in de vleesvarkensstal zijn alle biggen opgelegd in traditionele vleesvarkenshokken met 12 dieren per hok. De bevindingen van het onderzoek bij de zeugen, biggen en vleesvarkens zijn beschreven in dit rapport.
Public morals in private hands? : a study into the evolving path of farm animal welfare governance
Toschi Maciel, C. - \ 2015
University. Promotor(en): Arthur Mol; Bernd van der Meulen, co-promotor(en): Bettina Bock. - Wageningen : Wageningen University - ISBN 9789462572799 - 149
dierenwelzijn - vee - dierhouderij - overheidsbeleid - europese unie - brazilië - governance - nederland - rechtssystemen - animal welfare - livestock - animal husbandry - government policy - european union - brazil - netherlands - legal systems
Executive summary

The advancement of regulatory instruments providing for farm animal welfare measures has been marked by various political and regulatory constraints in both domestic and international settings.In an attempt to overcome some of these constraints, a number of innovative governance arrangements have been developed over the two last decades, such as the use of private standards.This thesis offers a critical assessment on how and to what extent the policy field of farm animals welfare has been affected by these innovative developments. The assessment provided in this thesis resulted from four independent (but inter-related) studies.

The first study consisted of a theoretical inquiry into the engagement of non-state actors in farm animal welfare policy making in Europe. This study sought to establish the extent to which the changes observed in Europe, specifically in the Netherlands, are consistentwith political modernization theory. This study confirmed that the engagement of non-state actors in farm animal welfare policy-makingin Europe corresponds to themodernization of governance practices, where a new collation of actors, policy discourses and rules come to the fore.

The second study consisted of an empirical investigation ofthe rise of farm animal welfare governance in Brazil. The main objective of this study was to gain insight into a development that remains largely unexplored in the current social science literature, that is, into the factors triggering policy change related to animal protection in developing countries. Data collected through 36 semi-structured interviews amongdifferent groups of Brazilian stakeholders suggested that the main factors leading to the rise of animal welfare governance in Brazil were related to Europe and the World OrganisationforAnimal Health (OIE). The insights gained fromthis exploratory empirical study helped produce an analytical framework for assessing how farm animal welfare measures spread across jurisdictions, which is further elaborated in the third phase of this doctoral research.

Accordingly, in the third study, an empirical and theoretical examination ofanimal welfare governance in the European Union-Brazildyad is performed with the objective of assessing theactors and mechanisms currently in place to advance farm animal welfare in bilateral and international relations. Several initiatives have been identified as useful in coordinating animal welfare measures between theEU and Brazil. The study nonetheless found that initiatives based on policy diffusion mechanisms were the most prominent.

The fourth study entailed a legal analysis ofthe relationship between the regulatory framework of the World Trade Organisation (WTO) and the advancement of animal welfare measures through private standards. The objective of this study was to determine the possibility thatprivate standards fall within the scope of WTO Member States’ obligations listedin Article 13 of the Sanitary and Phytosanitary Agreement (SPS). For that purpose, three fundamental factorsfor claims of breaches of Article 13 to be pursuedwere examined: (i) the applicability of the SPS Agreement to farm animal welfare measures; (ii) the scope of the term ‘non-governmental entities’; and (iii) the existence of factual evidence that a WTO Member has not taken reasonable measures to ensure that SPS disciplines are observed by non-governmental entities or that a WTO Member has encouraged non-governmental entities or have relied upon the services of non-governmental entities that are not SPScompliant. The conclusion drawn from this examination is that convincing legal arguments and factual evidence exist to pursue WTO disputes over the use of private farm animal welfare standards.

Based on all the above findings, the overall assessment of this thesis regarding the evolving path of farm animal welfare governance is four-fold.First, the policy field of farm animal welfare has significantly advanced in and between Europe and Brazil through a variety of non-legislative instruments, such as intergovernmental technical cooperation, capacity building programmes and private standards. Second, the political and regulatory implications of this research regarding the use of private standards in animal welfare indicate that a cautious approach to the use of this policy instrument is required. Third, the policy field of animal welfare has greatly benefited from the entry of the World Organisation for Animal Health (OIE), especially in engaging governments and industries in developing countriesin this area. Finally, a reverse shift (that is, a shift away from private governance and towards public governance) is likely to occur as the path of farm animal welfare policy evolves internationally.

Economic optimization of surveillance in livestock production chains
Guo, X. - \ 2015
University. Promotor(en): Alfons Oude Lansink, co-promotor(en): Helmut Saatkamp; Frits Claassen. - Wageningen : Wageningen University - ISBN 9789462572485 - 180
agrarische economie - optimalisatie - dierziekten - risico - risicobeheersing - gevaren - economie van de veehouderij - vee- en vleesindustrie - agro-industriële ketens - nederland - vee - agricultural economics - optimization - animal diseases - risk - risk management - hazards - livestock economics - meat and livestock industry - agro-industrial chains - netherlands - livestock

Abstract

Hazard surveillance in livestock production chains is an essential activity that is usually conducted by surveillance organizations. Its importance has been highlighted by the major crises that occurred in the field of livestock production and food safety during the last decades. Although extensive research has been conducted to achieve surveillance improvement in livestock production chains, they have limitations in terms of coverage of economic aspects and in the level of detail in modelling the interactions between hazard dynamics and surveillance activities. Hence, the dissertation aims to (1) improve the understanding of hazard surveillance in livestock production chains from an economic perspective, and (2) to apply the obtained knowledge for better model-based in-depth analysis of livestock hazard surveillance.

In this thesis, we first presents a conceptual framework for the economic analysis of single-hazard surveillance systems in livestock production chains which differs from most of the previous research focusing on the technical aspect of livestock hazard surveillance. We conclude that that the conceptual approach is scientifically credible for economic analysis of single-hazard surveillance systems and that the applicability of the approach critically depends on data availability. Then we present a conceptual framework for the economic optimization of a surveillance- portfolio consisting of multiple livestock hazards to survey. This framework applies the portfolio perspective to investigate the surveillance resource allocation problem, which is beyond the state of art that mainly focuses on single hazard surveillance analyses. The credibility and practicability of the framework were also checked.

To demonstrate the usefulness of the developed frameworks, two case studies are conducted. We applied the single-hazard surveillance framework to conduct a comprehensive economic analysis of classical swine fever (CSF) surveillance in the Netherlands. The results of the cost-effectiveness analysis show that the alternative surveillance setups with “PCR on rendered animals” are effective for the moderately virulent CSF strain, whereas the surveillance setups with “routine serology in slaughterhouses” or “routine serology on sow farms” are effective for the low virulent strain. Moreover, the current CSF surveillance system in the Netherlands is cost-effective for both moderately virulent and low virulent CSF strains. The results of the cost-benefit analysis for the moderately virulent CSF strain indicate that the current surveillance system in the Netherlands is adequate. From an economic perspective, there is little to be gained from intensifying surveillance. We also applied the surveillance-portfolio analysis framework to conduct economic optimization of a pig-hazard surveillance-portfolio, consisting of five pig-related hazards, in a Dutch food company. We draw the conclusion that surveillance organizations need to use a portfolio perspective to guide their surveillance resource allocation. This is because the case clearly shows that arbitrarily allocating surveillance resource can cause efficiency losses (either in terms of higher surveillance costs or low SP performance).

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