Effect of floor type on footpad injuries in does: a pilot study

Onderzoek naar de geschikte ondergrond om voetproblemen bij konijnen te voorkomen. Uit dit onderzoek lijkt het er op dat plastic matten een positieve invloed hebben op het voorkomen van voetproblemen. Meer onderzoek is echter noodzakelijk om hierover meer zekerheid te krijge

Transmission and quantification of verocytotoxin-producing Escherichia coli O157 in dairy cattle and calves

Data from a field study of 14 months duration in a naturally colonized dairy herd and data from an experiment with calves were used to quantify transmission of verocytotoxin-producing Escherichia coli (VTEC O157) in cattle. For the latter, two groups of 10 calves were randomly assigned and put out in one of two pastures. From each group, five animals were experimentally inoculated with 109 c.f.u. O157 VTEC and, considered infectious, put back in their group. Each of the susceptible contact calves became positive within 6 days of being reunited. The estimate of the basic reproduction ratio (R0) in the experiment was 7·3 (95% CI 3·92¿11·5), indicating that each infectious calf will infect seven other calves on average during an assumed infectious period of 28 days in a fully susceptible population. The R0 among dairy cows appeared to be about 10 times lower (0·70, 95% CI 0·48¿1·04). After the transmission experiment, six contact-infected animals that were shedding continuously during the experiment were housed in a tie stall during winter. After 40 days, all six tested negative for O157 VTEC. In June, after a period of 34 weeks in which the heifers remained negative, they were put out in a clean and isolated pasture to observe whether they started shedding again. On each pasture that was infected with O157 VTEC during the transmission experiment the previous summer, newly purchased susceptible calves were placed. None of the heifers or calves started shedding during 14 weeks, indicating that both the heifers and the previously contaminated pasture did not function as reservoir of O157 VTE

3 mm gaasbodem met matje geeft betere voetzolen

Dit artikel beschrijft een proef die in 2008 door ASG (Animal Siences Group) is uitgevoerd in samenwerking met de sector konijnenhouderij. Aanleiding is dat in de praktijk voetzoolbeschadigingen voorkomen bij voedsters, wat ongewenst is voor het welzijn van de dieren. Onderzocht is het effect van een kunststofmatje op de voetzoolkwaliteit van voedsters. Uit dit onderzoek blijkt dat een kunststofmatje op een 3 mm-gaasbodem betere voetzolen geeft dan een 3mm-gaasbodem zonder matj

Matje op de bodem geeft betere voetzolen bij voedsters

In de praktijk worden voedsters gehuisvest in hokken met een gaasbodem van 3 mm gaasdikte. Bij konijnen op deze bodems komen voetzoolverwondingen voor. Onderzoek bij ASG wijst uit dat door het aanbrengen van een kunststof matje op de gaasbodem voetzoolverwondingen bij voedsters worden voorkome

Hokverrijking om in de knaagbehoefte van konijnen te voorzien: een literatuurstudie = Environmental enrichment to fulfill gnawing requirements in rabbits: a literature study

This report is a literature study to environmental enrichment in rabbits, that possibly fulfills the gnawing requirement

Forecasting time series by means of evolutionary algorithms

Proceeding of: 8th International Conference in Parallel Problem Solving from Nature - PPSN VIII , Birmingham, UK, September 18-22, 2004.The time series forecast is a very complex problem, consisting in predicting the behaviour of a data series with only the information of the previous sequence. There is many physical and artificial phenomenon that can be described by time series. The prediction of such phenomenon could be very complex. For instance, in the case of tide forecast, unusually high tides, or sea surges, result from a combination of chaotic climatic elements in conjunction with the more normal, periodic, tidal systems associated with a particular area. Too much variables influence the behaviour of the water level. Our problem is not only to find prediction rules, we also need to discard the noise and select the representative data. Our objective is to generate a set of prediction rules. There are many methods tying to achieve good predictions. In most of the cases this methods look for general rules that are able to predict the whole series. The problem is that usually the time series has local behaviours that dont allow a good level of prediction when using general rules. In this work we present a method for finding local rules able to predict only some zones of the series but achieving better level prediction. This method is based on the evolution of set of rules genetically codified, and following the Michigan approach. For evaluating the proposal, two different domains have been used: an artificial domain widely use in the bibliography (Mackey-Glass series) and a time series corresponding to a natural phenomenon, the water level in Venice Lagoon.Investigation supported by the Spanish Ministry of Science and Technology through the TRACER project under contract TIC2002-04498-C05-