Seasonal energy requirements of wapiti (Cervus elaphus) for maintenance and growth

Abstract

Seasonal energy intakes of 6- to 14-mo-old wapiti hinds were determined in energy balance trials under pen and field conditions in winter, spring and summer. Six animals grazed native pastures supplemented with alfalfa hay when pasture availability declined in winter. Another six were penned and fed alfalfa-barley pellets to maximize growth throughout the year. Season and diet-specific metabolizable energy requirements for maintenance and liveweight gain were determined from regression of metabolizable energy intake on gain. Daily maintenance requirements of penned wapiti ranged from (mean ± SE) 473 ± 35 kJ kg−0.75 in winter to 728 ± 78 kJ kg−0.75 in summer. On spring and summer pasture, daily ecological maintenance requirements ranged from 900 ± 26 to 984 ± 37 kJ kg−0.75. Energy requirements for gain were the same in pen and field trials, ranging from 25 ± 6 to 33 ± 5 kJ g−1 in winter and from 40 ± 6 to 43 ± 12 kJ g−1 in spring and summer. This study provides basic information on the metabolizable energy needs of wapiti and insights into how their seasonal requirements can be optimally met. Key words: Elk, metabolizable energy requirement, growth, physiological maintenance, ecological maintenance, seasonality, energy balance