H.W. Saatkamp’s research while affiliated with Wageningen University & Research and other places

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Publications (177)


Study area: geographical location of Los Rios, with their two provinces (Valdivia and Ranco), La Araucanía and Los Lagos regions, Chile.
The figure describes the within-herd dynamics for a dairy herd. The herd has been divided into four groups: Calves (C), heifers (H), cows (Cw), and nonpregnant cows (NPCw). In addition, H and Cw were further divided into three age categories to correspond to the gestation trimester (H1, H2, H3, Cw1, Cw2, Cw3), with the purpose to address infection results regarding pregnancy stage (e.g., an earlier infection increases the probability to obtain a PI). Males were removed at birth, and culling was possible in each age group at a culling rate of 0.2 per year. At 400 days of age, calves (C) move to H1 (representing the age for a first pregnancy) [32]; then, heifers move every 93 days, first to H2 and then to H3. After calving, H3 moves to NPCw, representing the time between calving and pregnancy (60 days) [33]; after this period, the animal moves to C1 and then every 93 days first to C2 and then to C3 stage for calving and then back to NPCw again. The first step was to run the model without the introduction of infected animals, with the sole purpose of evaluating the herd dynamics in relation to age, production conditions, and management. The population was classified into several mutually exclusive health states with respect to BVDV infection: Susceptible (Sus), transiently infected (TI), persistently infected (PI), immune (Imm), recovered (Rc), immune fatally infected (ImmFI), maternal immune calves (MatCalv).
Simulated herd-profiles pathway of BVDV infections. Red boxes represent all infected herd-profiles, and green boxes represent all cleared herd-profiles. CHI, clear high immunity; CLI, clear low immunity; CMI, clear medium immunity; IHI, infected high immunity; ILI, infected low immunity; IMI, infected medium immunity.
BVDV outbreaks simulation results for a medium fully Sus dairy herd after a PI heifer introduction, time is shown in days. (A) The figure shows the first 600 days of the outbreak with median and interquartile range. (B) The figure shows the entire 12-year period with median and interquartile range. BVDV, bovine viral diarrhea virus; PI, persistently infected; Sus, susceptible; TI, transiently infected.
BVDV outbreaks simulation results for a medium fully Sus dairy herd after a PI heifer introduction, time is shown in days. (A) The figure shows the first 600 days of the outbreak with median and interquartile range. (B) The figure shows the entire 12-year period with median and interquartile range. BVDV, bovine viral diarrhea virus; PI, persistently infected; Sus, susceptible; TI, transiently infected.

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Herd-Level Modeling of Bovine Viral Diarrhea Virus (BVDV) Transmission in Cattle Herds in Southern Chile: Linking Within and Between-Herd Dynamics
  • Article
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October 2024

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39 Reads

Oscar Alocilla-Velásquez

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Helmut Saatkamp

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Stefan Widgren

Bovine viral diarrhea (BVD) represents a serious threat to the cattle sector in Chile, indicating the need for a regionally defined control program. Ex-ante evaluations of program options using simulation modeling have proven to be a successful approach in providing decision-makers with relevant supporting insights in that respect. Given the complexity of bovine viral diarrhea virus (BVDV) infection dynamics, simulation of BVD spread in a metapopulation requires detailed consideration of both within and between herd transmission dynamics. The aims of the study are (i) to investigate the dynamics of BVDV transmission in cattle herds in southern Chile by linking a within-herd transmission model (WHM) that accounts for the BVDV’s unique characteristics with a between-herd model (BHM) that meets the demands for further regional control strategy evaluation; (ii) to suggest and discuss criteria for evaluation of the model approach and plausibility for later research and for support decision-making. This resulted in bringing forth a modeling rationale for complex disease spread simulation in metapopulations. BHM simulations under this approach show outcomes that agree with BVDV’s known situation in Chile; dairy herds prevalence at endemic equilibrium reaches and maintains 75%, which agrees with estimations of BVDV active infection in dairy herds in southern Chile (77%). For the entire herd population, the infection always reaches endemic levels with a large proportion of infected herds (median = 60%), where herd prevalence was higher in the dairy herd class than in the remaining categories. Transmission probability variation affects the new infections picked, prevalence at endemic levels, and the velocity in which the infection spreads between herds. The fact that the presented approach was able to model a complex infection dynamic such BVDV, with sufficient confidence, provides evidence that this approach can be used to explore mitigation strategies to control BVDV in southern Chilean herds.

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One-size measures do not fit all areas: Evaluation of area-specific control of foot and mouth disease in Thailand using bioeconomic modelling

October 2024

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62 Reads

Preventive Veterinary Medicine

Bioeconomic modelling of Abstract Information on the epidemiological and economic consequences of control measures is fundamental to design effective foot and mouth disease (FMD) control measures. One approach to obtaining this information is through bioeconomic modelling. In this study, a bioeconomic model was used to evaluate FMD control in two different study areas in Thailand: a high farm density area predominantly consisting of dairy farms and a low farm density area with mixed farm types. The bioeconomic model consists of an epidemiological part and an economic part. For the epidemiological part, a stochastic between-farm transmission model was constructed with transmission parameters estimated from FMD outbreaks in Thailand. The outputs from the epidemiological model, i.e. the number of infected farms, the number of affected farms and the outbreak duration, are used as inputs for J o u r n a l P r e-p r o o f economic model to calculate the economic consequences. We applied the simulation model with four FMD control measures: culling the animals of infected farms, ring vaccination, animal movement restrictions and isolation of infected farms. Furthermore, we included effect of farmers' compliance to asses its effect on control measures. The simulated FMD outbreaks in the low farm density area were small, thus control measures did not greatly affect the size of outbreaks and, therefore, did not have a positive economic return. In contrast, in the high farm density area, FMD outbreaks were large without control measures. All measures reduced the size of the outbreaks but resulted in different total costs. In terms of outbreak control, culling infectious farms was the best option, but its total cost was higher than ring vaccination or isolation of infected farms. In terms of cost-effectiveness, ring vaccination was the best measure. If farmers' compliance were low, all control measures would be ineffective, resulting in high total cost of the outbreak. The cost distribution between compliant and non-compliant farms showed that non-compliant farms paid more than compliant farms, except for the ring vaccination scenario. The results emphasize the economic significance to customize control measures specific to the area's conditions and highlight the importance of farmers' compliance when designing control measures.


Farm characteristics and current production management decisions for nine arable case study farms from the Netherlands. For acronyms, see below
Economic optimization of sustainable soil management: a Dutch case study

October 2024

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39 Reads

Agronomy for Sustainable Development

Soil quality is pivotal for crop productivity and the environmental quality of agricultural ecosystems. Achieving sufficient yearly income and long-term farm continuity are key goals for farmers, making sustainable soil management an economic challenge. Existing bio-economic models often inadequately address soil quality. In this study, we apply the novel FARManalytics model, which integrates chemical, physical, and biological indicators of soil quality indicator, quantitative rules on how these indicators respond to farmers’ production management over time, and an economic calculation framework that accurately calculates the contribution of production management decisions towards farm income. This is the first study applying this model on existing arable farms. FARManalytics optimizes crop rotation design, cover crops, manure and fertilizer application and crop residue management. Nine Dutch arable farms were analyzed with a high variation in farm size, soil type, and cultivated crops. First, we assessed farm differences in soil quality and farm economics. Second, we optimized production management to maximize farm income while meeting soil quality targets using farm-specific scenarios. Third, we explored the impact of recent policy measures to preserve water quality and to increase the contribution of local protein production. The results show that the case farms already perform well regarding soil quality, with 75% of the soil quality indicators above critical levels. The main soil quality bottlenecks are subsoil compaction and soil organic matter input. We show that even in front-runner farms, bio-economic modeling with FARManalytics substantially improves economic performance while increasing soil quality. We found that farm income could be increased by up to €704 ha ⁻¹ year ⁻¹ while meeting soil quality targets. Additionally, we show that to anticipate on stricter water quality regulation and market shift for protein crops, FARManalytics is able to provide alternative production management strategies that ensure the highest farm income while preserving soil quality for a set of heterogenous farms.


Economic impact of inclusion of Black Soldier Fly products in broiler diets: a comparison between conventional and higher animal welfare production systems in the Netherlands

October 2024

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12 Reads

Poultry Science

The primary objectives of this study were to analyze economic feasibility of incorporating black soldier fly products in broiler feed and to compare the viability of alive (alive grown larvae (AGL)) or processed (defatted larvae meal (DLM) and insect oil) insect inclusion into the two Dutch broiler welfare systems: conventional and better life one star (BLS). An existing simulation model for insect production was adapted to build an economic model for the insect-fed broiler breast meat supply chain. Amounts, full costs, and breakeven prices of different production setups were compared and the impacts of specific input parameters were tested by sensitivity and breakeven analyses. Results indicated a hypothetical demand of 2.15 million tons wet matter of raw substrate to meet the total Dutch breast meat production (BLS broilers and 10% AGL inclusion). In case of 10% processed insect inclusion, the conventional broiler breast meat price increased from 3,947 to 6,069 €/t (53.7%) and the BLS breast meat price from 6,493 to 9,662 €/t (48.8%). Alive insect inclusion resulted in a smaller cost increase (42.2%) by skipping the costly processing step. To become price competitive, DLM or AGL must cost 618 or 801 €/ton dry matter (tDM), respectively, requiring a raw substrate mix price of -109 €/tDM. High input amounts and costs currently hinder the widespread adoption of insect products in Dutch mass poultry feed. However, in the long run, using negative value substrates or targeting niche markets for broiler welfare with low AGL inclusion levels could become viable business models. Research is needed on the impact of negative value substrates on insect production performance and contamination risks. Furthermore, the impact of varying AGL composition requires special attention.



Figure 3 Initiation of the supply chain production and flow of products and information in the technical module.
Figure 5 Flow of costs and cost composition of grown larvae in P&C. Left: cost composition of the intermediate inputs, seed larvae and ready substrate; middle: original cost composition of AGL; right: cost composition of AGL with intermediate inputs split up in their cost components.
Selected average storage days
Raw substrate description and composition that is used for the default scenario
Economic supply chain modelling of industrial insect production in the Netherlands

March 2024

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145 Reads

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5 Citations

Journal of Insects as Food and Feed

Defatted larvae meal (dLM), specifically from black soldier flies, could help overcome the animal protein gap. As insect production is an emerging sector, current economic research is scarce and very diverse. Thus, the aim of this research was to develop a simulation model that enables the analysis of full industrial scale costs of producing dLM and to provide insight in the distribution of these costs in the insect supply chain. The deterministic supply chain model is built on three modules, technical, transition and economic module, which all follow a previously defined supply chain structure and allow to extract quantity and price information for intermediate or final products. The model was parameterized and checked for plausibility in multiple consultation rounds with the INSECTFEED consortium and business partners. Additionally, model behaviour was checked with scenario, sensitivity, and break-even price analyses. In the default situation 5.57 tDM raw substrate and 26.7 million neonates are required to produce 1 tDM dLM for a price of €5,116/tDM. Most costs are added in the raw substrate delivery (€1,952/tDM) and production and collection (€821/tDM) step. Important cost factors are the raw substrate (€1,939/tDM) and building and inventory (€1,459/tDM). Parameters with high relative response rate towards the price of dLM are the feed conversion rate, dry matter percentage of larvae, raw substrate price, larvae density, labour wage and growth rate. To reach break-even prices for substituting fish meal with alive grown larvae (AGL) (€1,318/tDM AGL), improving production parameters is not sufficient. Just changing prices of raw substrate to −€78/tDM or frass to €1,175/tDM would enable a profitable operation. However, these are not deemed as realistic in mass production. Although there is some insecurity in data, the model results are the most realistic representation of industrial scale production amounts and costs.



Figure 1. The production function of a farm with a conventional production system. Production function () illustrates the relation between the output, meat (), and the productive input, feed (), for a specific farm with a conventional production system. The dashed line represents the isoprofit line. The slope of this line is
Figure 3. The production functions of a farm with a conventional production system and a farm with an improved production system. Production function () illustrates the relation between the output, meat (), and the productive input, feed (), for a farm with a conventional production system, while production function () illustrates the same input-output relation for a farm with an improved production system. The dashed lines represent isoprofit lines. The slope of these lines is
Figure 6. The optimal damage abatement effect of risk-neutral and risk-averse farmers. Damage abatement function () illustrates the relation between the damage abatement effect ( ) and the damage-abatement input use () for a farm with a conventional production system. The dashed lines represent isoprofit lines. The slope of one of these lines is = ⋅() . The slope of the other
The Economic Value of Antimicrobial Use in Livestock Production

October 2023

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73 Reads

(1) Introduction: Antimicrobial agents have played an important role in improving the productivity of worldwide livestock production by reducing the impact of livestock diseases. However, a major drawback of antimicrobial use is the emergence of antimicrobial-resistant pathogens in food-producing animals. To reduce the use of antimicrobials, it is important to know the economic value of the use of antimicrobials and factors that determine that economic value. (2) Results: A theoretical framework was developed to assess the economic value of antimicrobial use. Three situations were distinguished: firstly, a baseline model for a farm with a conventional production system; secondly, an extension of the baseline model that includes the impact of production system improvements; and thirdly, an extension of the baseline model that includes the impacts of risk and risk attitude. This framework shows that the economic value of antimicrobial use is negatively affected by the price of productive inputs and damage-abatement inputs, and positively affected by the output price, the input–output combination, the damage abatement effect, risk aversion and variance in profit. (3) Conclusions: The theoretical framework presented in this study shows that there are several factors that (can) affect the economic value of antimicrobial use. The knowledge about the effect of these factors can be utilized to affect the economic value of antimicrobials and, consequently, affect antimicrobial use.


Evaluation of foot and mouth disease control measures: Simulating two endemic areas of Thailand

October 2023

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86 Reads

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5 Citations

Preventive Veterinary Medicine

Foot and mouth disease (FMD) is an important livestock disease in Thailand, with outbreaks occurring every year. However, the effects of FMD control measures in Thailand have received little research attention. Epidemiological models have been widely used to evaluate FMD outbreak control, but such a model has never been developed for Thailand. We constructed a stochastic between-farm transmission model to evaluate FMD control measures. The epidemiological unit of the model was the farm, which could be in different states: susceptible, latent, undetected infectious, detected infectious and recovered. The between-farm transmission was calculated by the sum of distance-dependent transmission and trade network transmission using parameters derived from FMD outbreaks in 2016 - 2017. We used this model to simulate the outbreaks with and without the implementation of the following control measures: culling all animals on infected farms, ring vaccination, animal movement restrictions and isolation of infected farms. The control measures were evaluated by estimating the number of secondarily infected farms and the outbreak duration for each scenario. The model was simulated in two study areas located in the Lamphaya Klang subdistrict (high farm density) and the Bo Phloi district (low farm density). The effects of control measures differed between the two study areas. When farm density was high, rigid control measures were required to prevent a major outbreak. Among all options, culling the animals on infected farms resulted in the lowest number of infected farms and the shortest outbreak duration. In contrast, for an area with a low farm density, less stringent control measures were sufficient to control the usually minor outbreaks. The results indicate that different areas require a different approach to control an outbreak of FMD.


The influence of the cross-border innovation environment on innovation processes in agri-food enterprises – a case study from the Dutch-German Rhine-Waal region

April 2023

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83 Reads

NJAS Impact in Agricultural and Life Sciences

Enterprises of the agri-food and other sectors develop innovations that can serve the EU’s Green Deal objective to become climate-neutral by 2050. Innovation processes face specific innovation environment conditions, which are beyond the enterprise’s control. Our research aims to investigate how the innovation environment affects product innovation processes of agri-food enterprises located in a cross-border region. We developed our conceptual framework of the “cross-border innovation environment” based on innovation system and innovation management literature. We conducted semi-structured interviews in selected agri-food enterprises in the Dutch-German region Rhine-Waal. Results indicate that agri-food enterprises’ innovation environments concentrated on national-level factors, and that cross-border factors and relationships were rare. Moreover, different factors influenced different stages of innovation processes that were primarily driven by markets compared to research. We conclude that integrating customers and business partners during research and technological development is important to address current challenges of the Green Deal. Understanding how the innovation environment influences innovation processes in agri-food enterprises can help to develop appropriate policies.


Citations (76)


... Potential gains from increased soil quality are uncertain and typically manifest in the long term. For example, a higher organic matter input from compost, crop residue incorporation, or cover crops will increase SOM, but it is costly in the short term (Kik et al. 2024). (4) Trade-offs between agricultural productivity and environmental quality (O'Sullivan et al. 2018;Schulte et al. 2014;Stevens 2018). ...

Reference:

Economic optimization of sustainable soil management: a Dutch case study
FARManalytics – A bio-economic model to optimize the economic value of sustainable soil management on arable farms
  • Citing Article
  • July 2024

European Journal of Agronomy

... Our conclusions accord with those of Leipertz et al. (2024), who provide the most comprehensive model of the costs of insect production to date. Those authors find cost barriers significant enough to indicate that insects are unlikely to become a part of large-scale animal feed in the near future. ...

Economic supply chain modelling of industrial insect production in the Netherlands

Journal of Insects as Food and Feed

... Concerning the last step, the literature reports that EAS providers are becoming more involved in innovation processes due to the increasing use of facilitation, learning-based strategies (Blum, Cofini, and Sulaiman 2020), networking implemented by advisors , and also due to long-term support relationships -even informal -with farmers (Laurent et al. 2021). The innovation support models implemented by a diversity of advisory service actors underline the phenomenon of 'service-oriented' relationship within innovation support schemes, thus explaining the emergence of the concept of innovation support services (ISS) (Faure et al. 2019;Kilelu, Klerkx, and Leeuwis 2014;Mathé et al. 2020;Neuberger et al. 2023;Proietti and Cristiano 2022). The ISS concept is based on the need for a diversity of services provided by different actors to innovators to solve a problematic situation they have identified or to grasp an opportunity. ...

Do innovation support services meet the needs of agri-food SMEs in cross-border regions? A case study from the Euregio Rhine-Waal

The Journal of Agricultural Education and Extension

... This underscores the pivotal role of immunization in FMD prevention and control, highlighting the optimality of the current immunization measure in China. Nevertheless, it is crucial not to underestimate the importance of disinfection and culling in preventing FMD outbreaks resulting from chance events [40,41]. A balanced strategy that combines immunization, disinfection, and culling measures ensures a comprehensive approach to FMD prevention and control. ...

Evaluation of foot and mouth disease control measures: Simulating two endemic areas of Thailand

Preventive Veterinary Medicine

... The wide host range provides influenza A viruses with a high probability of genetic reassortment, resulting in zoonotic viruses that can spread to the human population. In particular, highly pathogenic avian influenza (HPAI) H5 viruses also have pandemic potential [3][4][5][6][7][8][9][10][11]. According to the WHO, HPAI H5 viruses have caused 904 human infections, including 464 deaths [12]. ...

Economic impact of Highly Pathogenic Avian Influenza outbreaks in Western Java smallholder broiler farms
  • Citing Article
  • December 2022

Preventive Veterinary Medicine

... Previous studies in different countries have shown that the spread of FMD is influenced by several risk factors, including agricultural and environmental aspects such as livestock population, climate conditions, and livestock markets [11,12]. Studies in West Java found that FMD outbreaks were associated with environmental factors, including altitude and vegetation, and livestock factors, including cattle population, milk production, and leather production [13]. ...

Epidemiology of Foot-and-Mouth Disease outbreaks in Thailand from 2011 to 2018

... In these areas, the challenges of dairy farming are heightened by consistently high temperatures and humidity levels throughout the year [1,2]. Dairy farming contributes 12.6% of Thailand's gross agricultural output, driven by increasing demand for animal-based food domestically and internationally [3,4]. Most farms are small-scale, providing income stability to rural communities, especially in the Central and Northeastern regions, which produce 70% of the country's milk [5]. ...

Analysis of Epidemiological and Economic Impact of Foot-and-Mouth Disease Outbreaks in Four District Areas in Thailand

... The escalating world demand for protein, coupled with the global sustainability challenges confronting traditional protein sources [1][2][3][4][5], has prompted the exploration of alternative sources like insect meal [6]. Insects are increasingly favoured as an alternative protein source due to their potential to mitigate future protein shortages and their minimal environmental footprint [7]. ...

Development of sustainable business models for insect-fed poultry production: opportunities and risks

Journal of Insects as Food and Feed

... This complex organizational structure makes the timely transmission of information challenging and complicates the establishment of a sector-wide surveillance system, increasing the risk of disease spread (Indrawan, 2019). Many diseases such as avian influenza (AI) and Newcastle disease (ND) are now endemic in Indonesia and continue to cause significant economic losses (Indrawan et al., 2020;Pramuwidyatama et al., 2022;Sudarman et al., 2010;Sumiarto and Arifin,). Despite the existence of a national animal health surveillance system, referred to as iSIKHNAS (Challenges of Animal Health Information Systems and Surveillance for Animal Diseases and Zoonoses, 2011; Directorate General of Livestock and Animal Health Services Ministry of Agriculture,; FAO, 2021), its uptake by the poultry sector has been limited, for which the reasons are yet to be investigated. ...

Smallholder Broiler Farmers' Characteristics to Uptake Measures Against Highly Pathogenic Avian Influenza in Western Java

... Moreover, most studies have focused on known single or multiple ARGs of interest [8], overlooking potentially significant but less characterized ARGs. In previous research, regression curves were used to predict ARGs by considering the correlation between multiple variables and establishing statistical models [9]. ...

Risk factors for the abundance of antimicrobial resistance genes aph(3′)-III, erm (B) , sul2 and tet (W) in pig and broiler faeces in nine European countries

Journal of Antimicrobial Chemotherapy