Digestion and chewing behaviour of young sambar and red deer consuming a low quality roughage

Abstract

SUMMARYLow quality chaffed meadow hay, containing 10·5 g N/kg dry matter (DM), was fed to four artificially reared sambar (tropical) deer (Cervus unicolor) and four red (temperate) deer (Cervus elaphus) confined indoors in metabolism crates at Palmerston North, New Zealand, during March and April 1994. Measurements were made of DM intake (DMI), apparent digestibility, nitrogen (N) retention and the time spent eating and ruminating. Voluntary food intake (VFI), measured over days 7–11, was substantially greater for red deer than for sambar deer (67 v. 36 gDM/kgW0·75/day). Dry matter intake of red deer was then restricted, so that apparent digestibility could be better compared between the two species. Eating and ruminating time/gDMI and chews during eating/gDMI were all greater for sambar deer than for red deer. Apparent digestibility of DM, organic matter (OM) and energy were low (c. 0·42) and not different between deer species. Apparent digestibility of neutral detergent fibre (NDF) and cellulose were highest for red deer, but lignin apparent digestibility was highest for sambar deer. Both deer species lost weight and were in negative N balance. However, despite their lower N intake, sambar deer lost significantly less N and liveweight per day (– 5·6 g and – 118 g) than red deer (– 12·2 g and – 258 g). It was concluded that red deer responded to a diet of low quality roughage by increasing VFI and cellulose digestion, whilst sambar deer responded with a lower VFI but greater chewing activity, improved lignin digestion and better N conservation. Rumen mean retention time should be measured in future experiments with sambar deer and red deer fed on low quality forage diets.