Seasonal intake determination in reproductive wapiti hinds (Cervus elaphus canadensis) using n-alkane markers

Abstract

We used bite-count and double n-alkane ratio techniques to estimate dry matter intake (DMI) of wapiti hinds on heavily or lightly grazed pastures, during important reproductive phases (early/late gestation, peak/late lactation). Despite seasonal differences in phytomass between pastures, differences in DMI were not significant and results were pooled for seasonal comparisons. The annual nadir of intake occurred in late gestation (3.44 ± 0.17 kg DM d-1) despite the nutrient demands of the rapidly growing foetus. Spring weight loss (-2.9 ± 0.8 g kg-0.75 d-1) reflected the inability of hinds to graze sufficiently to meet these nutritional requirements, even though herbage quality was at its seasonal peak. Although energy requirements peaked during early lactation, hinds were able to consume enough high quality forage (5.38 ± 0.25 kg DM d-1) to achieve compensatory growth (12.5 ± 1.4 g kg-0.75 d-1). Continued elevated intakes through late summer (5.32 ± 0.41 kg DM d-1) and autumn (4.41 ± 0.24 kg DM d-1) ensured that hinds regained adequate condition for the breeding season.