Energy requirements of antarctic sledge dogs.

1. Eighteen male sledge dogs were weighed immediately on removal from their sheltered winter quarters at Halley Bay, Antarctica (75 degrees 31' s, 26 degrees 42' W) and weekly thereafter for 14 weeks. The first 2 weeks they were tethered and inactive and the following 12 weeks travelled an average of 10.9 km/d fully laden. Daily energy intake during winter and while tethered averaged 18-25 MJ/d and while travelling 13.9 MJ/d. 2. Mean weight loss during the 2 weeks of inactivity was 2.3 kg despite an energy intake almost twice the recommended requirement. During the 12 weeks travelling energy intake decreased to 13.9 MJ/d but the weight loss stopped. Weather conditions at this time were becoming progressively milder. 3. The evidence suggests that sledge dogs are capable of high levels of cold-induced and possibly diet-induced thermogenesis and that these factors, particularly the former should be taken into account when designing dog rations and feeding schedules.