The energy costs of walking on the level and on negative and positive slopes in the Granadina goat (Capra hircus)

The energy expenditure of six goats averaging 35 (SE 0.3) kg was measured when the animals were standing or walking on a treadmill enclosed in a confinement-type respiration chamber at different speeds (0.167, 0.333 and 0.500 m/s) and slopes (-10, -5, 0, +5 and +10%). The energy costs of locomotion, estimated from the coefficients of linear regressions of heat production (HP) per kg body weight v. distance travelled were 1.91, 2.33, 3.35, 4.68 and 6.44 J/kg BW per m for -10, -5, 0, +5 and +10% inclines respectively, indicating that the energy expenditure of walking over standing changes with slope according to a slightly curvilinear relationship. The energy cost of raising 1 kg body weight one vertical metre was found to be 31.7 J, giving an average efficiency for upslope locomotion of 30.9%. The energy recovered on vertical descent was estimated as 13.2 J/kg per m, indicating an efficiency of the energy recovered above the theoretical maximum.