Estimating energy intake of free-ranging moose cows and calves through collection of feces

Abstract

We calculated the daily energy intake of wintering cow and calf moose from a series of 24-h feces collections and from estimates of the digestibility and energy content of forages from four different habitats in Norway during a 3-year period (1984–1986). Habitats varied in condition from good to poor. In early winter, the estimated energy intake of cows ranged from 803 kJ∙kg−0.75∙day−1 in the good- and average-quality habitats to 573 kJ∙kg−0.75∙day−1 in the poor habitat. Estimated energy intake decreased by 15–30% from early to late winter. The estimated energy intake of calves ranged from 920 kJ∙kg−0.75∙day−1 in the good habitat to 414 kJ∙kg−0.75∙day−1 in the poor habitat; a significant decrease over winter was not evident. The estimates of daily energy intake correspond to a browse wet mass of 8–17 kg for cows and 4–10 kg for calves. In the good- and medium-quality habitats the average energy deficiency of adult cows over winter was estimated at 25–30%.