Fig. 3. Asymptotic food intake of lactating female mice exposed to 30°C (N=67) as a function of litter size. Asymptotic food intake is the mean value for days 9-13 of lactation. Litter size is that on day 14 of lactation. Females with 6 pups ate more food than those with 1-3 pups. For litter size increasing from 6 to 15, no further increase in asymptotic food intake was observed (for statistical details, see Results).