Planimetric measurement of floor space covered by fattening rabbits and breeding does in different body positions and weight classes

The aim of this study was to measure the floor space that a rabbit occupies due to its physical size and shape. For this purpose the colour contrast planimetric method “KobaPlan” was used which had originally been developed to calculate the surface of chickens. A total of 704 images of fattening rabbits and breeding does were taken from a top view. The rabbits were weighed individually, and photographed digitally in a special planimetric box. In the photo, the number of animal associated pixels was counted by the “KobaPlan” software, and thus the area covered by the animal was calculated. The calculated surfaces of the rabbits were assigned to weight classes which covered a range from 1.0 to 5.5kg. We defined four body postures of rabbits, one sitting position and three different recumbent positions. The mean floor space covered by sitting rabbits at the beginning of the fattening period was 246±34cm², whereas recumbent rabbits covered 294±45cm², 360±51cm² and 338±39cm² in different positions. At the time of slaughter, the covered floor spaces increased to 509±23cm² for sitting rabbits, and to 697±45cm², 724±26cm² and 719±23cm² for recumbent rabbits, respectively. The calculated surface of breeding does with a body weight of 4.5kg was 657±17cm² in sitting position, and 828±7cm², 874±23cm² and 882±14cm² in the different recumbent positions. The heaviest does (5.5kg) covered 739cm² sitting and 1026±27cm² recumbent. There was a linear increase in the surface covered by rabbits in all defined body positions as a function of live weight. Furthermore, sitting rabbits covered significantly less floor space than lying rabbits (P<0.05). It was shown that the colour contrast planimetric method “KobaPlan” provides reliable results regarding the floor space covered by growing rabbits and breeding does. This study is a first step towards an optimization of current rabbit housing regarding individual space requirement, and it represents a useful basis for planning new environmental enrichment structures (e.g. withdrawal areas) in rabbitries.