Acknowledgements Book of abstracts - Publicaties - Vlaanderen.be

Margot Sprenger presents Workshop paper 9
In workshop 4: Reliability of scoring cow lameness
Friday, 12 September 2008 from 14h00-15h45 in the Het Pand chaired by Annelies van Nuffel
184
Workshop paper 9
RELIABILITY OF CATEGORIAL VERSUS CONTINUOUS SCORING OF
WELFARE INDICATORS: LAMENESS IN COWS AS A CASE STUDY
M. Sprenger 1 , A. Van Nuffel 2 , W. Maertens 2 , S. Van Dongen 3 , K. van Reenen 4 , F.A.M.
Tuyttens 1
1 Animal Sciences, Institute for Agricultural and Fisheries Research, Melle, Belgium
2 Technology and Food Unit, Institute for Agricultural and Fisheries Research, Melle, Belgium
3 Department of Biology, Faculty of Science, University of Antwerp, Antwerp, Belgium
4 Animal Sciences Group, Wageningen UR, Lelystad, The Netherlands
Many welfare problems that are assessed by means of welfare assessment protocols vary on a
continuous scale. Nevertheless, it is common practice to score such welfare indicators using a small
number of discrete categories rather than on a continuum. The rationale for doing so presumably
relates to the desire to simplify scoring methods and to increase the likelihood of observers
allocating the same score to the same observation in order to improve data reliability. On the other
hand, when scores between observers do not match, the magnitude of the error is likely to increase
when the number of classes on the scoring scale is reduced.
Lameness in cows will be used as a case study for testing which of these two opposing effects has
the greatest influence on data reliability. Using a first set of video images, participants will be
trained to score the severity of gait irregularities using the Welfare Quality 3-point scale.
Subsequently, consensus will be sought on where all 3 discrete scores should be situated on a
continuous scale. The participants will then be divided in two groups (A and B). A second set of
videos will be scored using the 3-point scale by group A, and using the continuous scale by group
B. The inter-observer reliability of both scoring methods will thus be compared.
Participants will discuss their experiences when using the different scoring methods and whether or
not findings from this experiment are likely to apply to other welfare indicators. The results may be
used for simulating statistical power and performance of both scoring methods for differentiating
farms or experimental treatments.
Contact information: Margot Sprenger or email margot.sprenger@ilvo.vlaanderen.be
Complete address: Institute for Agricultural and Fisheries Research (ILVO) Animal Sciences -
Animal Husbandry & Welfar,e Scheldeweg 68, B-9090 Melle, Belgium
Species: Broiler