Static spatial requirements of growing-finishing and heavy pigs

The objective of this study was to estimate the space occupied by a pig, calculated from direct measurements on the animal or from digital images. A total of 100 pigs with body weight (BW) ranging from 47 to 198 kg were individually weighed and measured for body length, back and shoulder height. The area of the rectangle into which each pig can be fitted was calculated, following the same method as Petherick and Baxter [Petherick, J.C., Baxter, S.H., 1981. Modelling the static spatial requirements of livestock. In: MacCormack, J.A.D. (Ed.), Proceedings of the CIGR Section II Seminar on Modelling, Design and Evaluation of Agricultural Buildings, Aberdeen, August 1981, Scottish Farm Buildings Investigation Unit, Bucksburn, Aberdeen, UK. pp 75–82]. In addition, pictures of the pigs were taken with a digital camera at the same distance and resolution to estimate the area of the geometrical shape of each animal by counting the number of pixels. Values of Petherick and Baxter's data space (A = 0.047 × BW0.67) are significantly higher (p < 0.0001) than those found with our linear measurements (A = 0.041 × BW0.67). The areas calculated from linear measurements support the EU Council Directive 2001/88/EC for pigs in the weight class of 115–150 kg, but not for growing pigs. This is because the area recommended for pigs of 110 kg corresponds only to our minimum space allowance, as estimated from digital image analysis (A = 0.028 × BW0.67).