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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Effects of bovine respiratory disease on the productivity of dairy heifers quantified by experts
Fels-Klerx, H.J. van der; Saatkamp, H.W. ; Verhoeff, J. ; Dijkhuizen, A.A. - \ 2002
Livestock Production Science 75 (2002). - ISSN 0301-6226 - p. 157 - 166.
The aim of the current study was to obtain expert data on the effects on productivity (EPs) associated with bovine respiratory disease (BRD) in dairy heifers. Expert knowledge on the EPs of BRD was elicited because a complete insight into these effects was not available from the literature. The experts' assessments of the EPs were quantified, applying the computerised ELI technique, by means of subjective probability density functions (PDFs). For each EP, the individual experts' PDFs were aggregated, hereby weighting the experts according to their expertise, to obtain a single weighted distribution per parameter. Results indicated that mortality following severe pneumonia in heifers <3 months was assessed to be increased by nearly 20ørange 16–24Ž Body weight of diseased heifers was estimated to be reduced by 10 kg (range 2–18 kg) at 3 months, up to 29 kg (range 23–36 kg) at 14 months. Furthermore, pneumonia was assessed to delay first calving age with half a month (range 0.1–0.9 months), and to reduce first lactation milk production by about 2ø150 kg, range 40–250 kg). BRD outbreaks in heifers 3 months were also estimated to reduce body weight at 14 months with approximately 30 kg (range 11–54 kg). The resulting EPs following BRD outbreaks were found to be less severe, and only occasionally as detrimental as the EPs associated with early pneumonia. It was concluded that the expert data obtained provide valuable information for economic decision-making in dairy practise.
'Inventarisatie van het onderzoek naar slijtende koeien.'
Meijer, G.A.L. ; Bouma, A. ; Verhoeff, J. - \ 2001
Unknown Publisher
Inventarisatie van het onderzoek naar slijtende koeien
Meijer, G.A.L. ; Bouma, A. ; Verhoeff, K. - \ 2001
In: Jaarboek Koninklijke maatschappij voor diergeneeskunde 2000
Mogelijkheden voor nader onderzoek naar de slijterproblematiek. [Chronic wasting of dairy cows: a review of research]
Meijer, G.A.L. ; Bouma, A. ; Verhoeff, J. - \ 2001
Tijdschrift voor Diergeneeskunde 126 (2001). - ISSN 0040-7453 - p. 223 - 225.
Modelling epidemiological and economic consequences of bovine respiratory disease in dairy heifers
Fels-Klerx, H.J. van der - \ 2001
Wageningen University. Promotor(en): A.A. Dijkhuizen; R.B.M. Huirne; J. Verhoeff. - S.l. : S.n. - ISBN 9789058085375 - 167
melkvee - vaarzen - rundveeziekten - ademhalingsziekten - melkveebedrijven - kostenanalyse - melkresultaten - computersimulatie - simulatiemodellen - epidemiologie - agrarische economie - nederland - dairy cattle - heifers - cattle diseases - respiratory diseases - dairy farms - cost analysis - dairy performance - computer simulation - simulation models - epidemiology - agricultural economics - netherlands

Bovine respiratory disease (BRD) is an important health problem in dairy heifers. BRD causes considerable losses, particularly on farms that experience high levels of the disease. However, an exact quantification of the economic losses due to BRD was not available yet. Despite this lack of economic insight, dairy farmers have to make decisions with regard to prevention of the disease. To make these decisions as economically sound as possible, more accurate insight is necessary into the economic consequences of BRD on the individual dairy farm.

The main objective of the research project described in this thesis was to obtain insight into the on-farm economic consequences of BRD in dairy heifers by means of a PC-based simulation model. The second objective was to collect information on the epidemiological consequences of the disease indispensable for model input.

The research started with a literature review aimed at obtaining the necessary qualitative and quantitative information on both the effects of BRD on the productivity of dairy heifers and risk factors of the disease. Because relevant literature turned out to be scarce, a formal expert judgement study was held to obtain additional data on the(se) variables of interest.

As a next step, a simulation model was developed that calculates the economic losses due to BRD in dairy heifers for individual dairy farm conditions in the Netherlands. Following the results of the expert judgement study, the model distinguishes between two BRD types, being calf pneumonia and a seasonal BRD outbreak.

Model calculations showed that for most dairy farms in the Netherlands the economic losses due to BRD will be relatively small: around 1 % of the farm's net return to labour and management for average situations, increasing up to 3-4 % at worst. For individual farms that experience high levels of BRD, the associated losses can be as high as 10-15 % of the farm's net return to labour and management, up to 25 % for large farms. Besides for calculation of the economic losses due to BRD, the model showed also to be useful for evaluation of the on-farm cost-effectiveness of prevention of the disease. Moreover, the model is flexible and user-friendly, hence, can be used as a tool to support decision-making in dairy practice.

Preventieve maatregelen voor een gezonde bedrijfsvoering
Hanekamp, W.J.A. ; Verhoeff, J. - \ 2000
Lelystad : Praktijkonderzoek Veehouderij (Rapport / Praktijkonderzoek Veehouderij 193) - 18
melkveehouderij - rundveeziekten - infectieziekten - demonstratiebedrijven, landbouw - proefbedrijven - landbouwvoorlichting - dairy farming - cattle diseases - infectious diseases - demonstration farms - pilot farms - agricultural extension
In dit rapport zijn allereerst de kenmerken van de genoemde besmettelijke dierziekten beschreven (hoofdstuk 2) gevolgd door een opsomming en toelichting van vier hoofdmaatregelen (hoofdstuk 3). Aansluitend is aangegeven op welke manier over deze maatregelen gecommuniceerd is (hoofdstuk 4). Een afsluitende evaluatie staat aan het eind (hoofdstuk 5).
Ziekterisico kan flink omlaag
Hanekamp, W. ; Verhoeff, K. - \ 1999
Praktijkonderzoek Rundvee, Schapen en Paarden. Praktijkonderzoek 12 (1999)5. - ISSN 1386-8470 - p. 3 - 5.
melkveehouderij - rundveeziekten - ziekteoverdracht - zoönosen - diergezondheid - gezondheidszorg - dairy farming - cattle diseases - disease transmission - zoonoses - animal health - health care
Aankoop van vee is een grote risicofactor voor de insleep van dierziekten. Mensen die in contact komen met dieren op verschillende bedrijven dienen bedrijfskleding aan te trekken. Jongvee is erg gevoelig voor bepaalde ziektekiemen. De overdracht van ziektekiemen van oudere dieren via bijvoorbeeld mest en melk moeten dan ook voorkomen worden.
Weinig besmettelijke dierziekten op PR proefbedrijven
Hanekamp, W. ; Verhoeff, K. - \ 1999
Praktijkonderzoek Rundvee, Schapen en Paarden. Praktijkonderzoek 12 (1999)1. - ISSN 1386-8470 - p. 20 - 21.
dierpathologie - melkvee - proefbedrijven - infectieziekten - ziektebestrijding - ziektepreventie - animal pathology - dairy cattle - pilot farms - infectious diseases - disease control - disease prevention
In twee jaar tijd is door natuurlijk verloop het percentage met IBR besmette dieren gehalveerd. De meeste proefbedrijven hebben voor Paratbc de onverdachtstatus 6. Eén bedrijf is besmet en volgt een bestrijdingsplan. Met name het dagelijks terugkerende kalvermanagement vraagt de meeste aandacht.
Fungal extracellular polysaccharides in house dust as a marker for exposure to fungi : Relations with culturable fungi, reported home dampness and respiratory symptoms
Douwes, J. ; Sluis, B. van der; Doekes, G. ; Leusden, F. van; Wijnands, L. ; Strien, R. van; Verhoeff, A. ; Brunekreef, B. - \ 1999
Journal of Allergy and Clinical Immunology 103 (1999). - ISSN 0091-6749 - p. 494 - 500.
Situatie besmettelijke aandoeningen op proefbedrijven
Hanekamp, W. ; Verhoeff, J. - \ 1998
Praktijkonderzoek Rundvee, Schapen en Paarden. Praktijkonderzoek 11 (1998)5. - ISSN 1386-8470 - p. 32 - 33.
diergeneeskunde - melkvee - leptospirose - Pestivirus - salmonellose - rhinotracheïtis - paratuberculose - medische behandeling - proefbedrijven - Nederland - veterinary science - dairy cattle - leptospirosis - salmonellosis - rhinotracheitis - paratuberculosis - medical treatment - pilot farms - Netherlands
Alle PR-proefbedrijven zijn leptospirose vrij. Ook BVD en salmonellose lijken geen grote problemen te geven. Op één na moeten alle bedrijven wel enten tegen IBR. Ook PARA-tbc verdient nog aandacht
Daily mortality in the Netherlands and outdoor air pollution.
Hoek, G. ; Verhoeff, A. ; Foscher, P. ; Wijnen, J. van; Brunekreef, B. - \ 1998
American Journal of Respiratory and Critical Care Medicine 157 (1998). - ISSN 1073-449X - p. A879 - A879.
An inactivated gE-negative marker vaccine and an experimental gD-subunit vaccine reduce the incidence of bovine herpesvirus 1 infections in the field.
Bosch, J.C. ; Jong, M.C.M. de; Franken, P. ; Frankena, K. ; Hage, J.J. ; Kaashoek, M.J. ; Maris-Veldhuis, M.A. ; Noordhuizen, J.P.T.M. ; Poel, W.H.M. van der; Verhoeff, J. ; Weerdmeester, K. ; Zimmer, G.M. ; Oirschot, J.T. van - \ 1998
Vaccine 16 (1998). - ISSN 0264-410X - p. 265 - 271.
An inactivated glycoprotein E-negative vaccine and an experimental glycoprotein D-subunit vaccine against bovine herpesvirus 1 (V1) were examined for their effectiveness in a randomized, double-bline, placebo-controlled field trial comprising 130 dairy farms. The use of these marker vaccines enabled us to monitor the incidence of infections in vaccinated populations. The aims of this trial were to evaluate whether these vaccines: (1) reduce the proportion of outbreaks in dairy herds; and (2) reduced virus transmission within dairy herds and to what extent. Vaccination with either of the two vaccines significantly reduced the proportion of herds wherein an outbreak occurred as well as the virus transmission within herds, as compared to placebo-treated herds. The estimated number of secondary cases caused by one infectious animal, expressed as the reproduction ratio R, was for both vaccines significantly >1. This indicates that when BHV1 is introduced into vaccinated herds, major outbreaks may still occur
An epidemiological and economic simulation model to evaluate the spread and control of infectious Bovine Rhinotracheitus in The Netherlands.
Vonk Noordegraaf, A. ; Buijtels, J.A.A.M. ; Dijkhuizen, A.A. ; Franken, P. ; Stegeman, J.A. ; Verhoeff, J. - \ 1998
Preventive Veterinary Medicine 36 (1998). - ISSN 0167-5877 - p. 219 - 238.
Bovine herpesvirus type I (BHV1), causing infectious bovine rhinotracheitis (IBR), was introduced in the Netherlands in 1971. In 1993, about 42% of the dairy cows had antibodies against BHV1. In the future, stricter requirements are anticipated regarding the health status of exported breeding cows and material. To support policymakers in their decisions on IBR eradication, a simulation model was developed in which the epidemiological and economic consequences of various control strategies were evaluated. This paper describes the model and provides an overview of some important outcomes. In the model, dairy herds were classified into different disease states based on (1) the reproduction ratio of the disease (R, defined as the number of secondary cases caused by one infectious animal) (2) the within-herd prevalence, within each value of R and (3) the expected number of infectious animals in an infectious herd within each prevalence range. The dynamic transition probability of a herd going from one state to another per week depends on direct contacts between animals, and other contacts such as transmission through fomites, indirect transmission through other species, airborne transmission and minor disease-specific routes such as venereal or iatrogenic transmission. Five control strategies, including both a voluntary vaccination program and a compulsory vaccination program for all dairy herds were evaluated. A voluntary vaccination program with 50% participation is not expected to lead to eradication of IBR. It appears that compulsory vaccination would be necessary to reach an IBR-free status.
Home dampness, dust mite allergy and childhood respiratory disease: a case control study.
Brunekreef, B. ; Slob, R. ; Jansen, N. ; Verhoeff, A.P. - \ 1997
Allergo Journal 6 (1997). - p. 250 - 255.
An epidemiological and economic simulation model to evaluate the spread and control of Infectious Bovine Rhinotracheitis in dairy cattle.
Vonk Noordegraaf, A. ; Buijtels, J.A.A.M. ; Dijkhuizen, A.A. ; Franken, P. ; Stegeman, J.A. ; Verhoeff, J. - \ 1997
In: Proc. Dutch/Spanish Symp. Animal Health and Management Economics, Anders et al. (eds.), Copenhagen, 23-24 January 1997, Dina Notat 56 (1997) 21-27. Also: Proc. VIIIth Int. Symp. Vet. Epidemioloy & Economics (ISVEE), Paris (1997) 13.9.1-3
Daily mortality and air pollution in The Netherlands.
Hoek, G. ; Verhoeff, A. ; Fischer, P. - \ 1996
Unknown Publisher
Air pollution and daily mortality in Amsterdam.
Verhoeff, A. ; Hoek, G. ; Schwartz, J. ; Wijnen, J.H. van - \ 1996
Epidemiology 7 (1996). - ISSN 1044-3983 - p. 225 - 230.
Infant respiratory symptoms in relation to mite allergen exposure.
Strien, R.T. van; Verhoeff, A.P. ; Wijnen, J.H. van; Doekes, G. ; Meer, G. de; Brunekreef, B. - \ 1996
European Respiratory Journal 9 (1996). - ISSN 0903-1936 - p. 926 - 931.
Bovine herpesvirus 1 marker vaccines reduce the incidence of infections.
Bosch, J.G. ; Frankena, K. ; Franken, P. ; Hage, J.J. ; Jong, M.C.M. de; Kaashoek, M.J. ; Maris-Veldhuis, M.A. ; Noordhuizen, J.P.T.M. ; Poel, W.H.M. van der; Verhoeff, J. ; Weerdmeester, K. ; Zimmer, G.M. ; Oirsch, J.T. van - \ 1996
In: Proc. 19th World Buiatric Congress, Edinburgh UK, Vol. I - p. 42 - 44.
The value of bulk milk ELISA Ostertagia antibody titres as indicators of milk production response to anthelmintic treatment in the dry period.
Kloosterman, A. ; Ploeger, H.W. ; Pieke, E.J. ; Lam, T.J.G.M. ; Verhoeff, J. - \ 1996
Veterinary Parasitology 64 (1996). - ISSN 0304-4017 - p. 197 - 205.
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