Swine—Floor Contact Area as a Function of Body Weight and Posture

Empirical regression equations were calculated for the relations between body weight and floor contact area of swine in various lying postures over a body weight range of 14 to 90 kilograms. Although exponential regressions had somewhat higher coefficients of determination (r2), simple linear or curvilinear equations gave acceptable fits. The four postures and their associated empirical formulas [A=floor contact area (cm2); W=body weight (kg)] were: fully relaxed, flat on one side, A=499+24.8 W (r2=.84); supported by two legs, A=250+20.4 W (r2=.97); supported by three legs, A=247+16.7 W (r2= .84); and supported by four legs, A=581 − 12.1 W+0.23 W2 (r2=.86). Expressed as proportions of total surface area (estimated from Brody's formula: S=970 W.633), floor contact areas for respective lying postures were: 16, 12, 10, and 6 percent for a 70 kg pig. Preliminary observations were made on neonatal calves and lambs. In the normal lying posture, calf-floor contact area was about 25 cm2 per kg of body weight; when lying on one side, it was 45 (cm2 kg−1). Lamb-floor contact area averaged 66.5 (cm2 kg−1) in various lying postures.