Digestion and absorption ofEucalyptus essential oils in greater glider (Petauroide svolans) and brushtail possum (Trichosurus vulpecula)

Abstract

Measurements were made of the quantity and composition of the steam-volatile essential oils in gastrointestinal tract contents of greater gliders fedEucalyptus radiata foliage and brushtail possums fedE. melliodora foliage. In both species, there was less oil in the stomach contents than in an equivalent mass of foliage. Only minor losses of leaf oils occurred during mastication by greater gliders, and absorption from the stomach appeared to be the major reason for the difference in the oil content of ingested leaves and of stomach contents. The apparent digestibility of oils over the whole gut was 96-97 %, although oils from the cecum and feces of both species contained compounds not present in the original leaf oils. Absorption of oils before they reach the hindgut should reduce the severity of antimicrobial effects but may involve a metabolic cost to the animal in detoxification and excretion.

Biotransformation of 1,8-cineole in the brushtail possum (Trichosurus vulpecula)

“…However, it is interesting to note that in previous studies the present authors failed to ® nd faecal metabolites of terpenes in folivorous marsupials (McLean et al 1993, Boyle et al 1999, 2000. Before these reports, examination of faeces has generally been limited to searching for unchanged oil (Southwell et al 1980, Foley et al 1987.…”

Petauroides volans (Diprotodontia: Pseudocheiridae)

“…Petauroides volans is close to the lower limit of body weight at which mammals could be expected to sustain a strictly folivorous diet, and for this reason the species' nutrition, digestion, and metabolism have been of particular interest to animal physiologists (Dash 1988;Foley 1987;Foley andHume 1987a, 1987b;Foley et al 1987Foley et al , 2004Hume 1982Hume , 1999Hume , 2004Hume et al 1984;McIlwee et al 2001). Various strategies are used to cope with the highfiber, low-nutrient diet and the metabolic burden of detoxifying secondary plant compounds including selective retention of fine particulate digesta in the oversized cecum (Foley and Hume 1987a;Hume 1999).…”

Plant Genetics Affects Arthropod Community Richness and Composition: Evidence From a Synthetic Eucalypt Hybrid Population

“…(e.g., 1,8-cineole in E. camaldulensis, h 2 ϭ 0.52; Doran and Matheson 1994). In apparent response to these defenses, herbivores have evolved behavioral and physiological mechanisms to avoid and/or detoxify these oils (Morrow et al 1976;Morrow and Fox 1980;Foley et al 1987;Ohmart and Larsson 1989). We examined how oils were distributed among E. amygdalina, E. risdonii, F 1 , and F 2 hybrids in this commongarden trial and then quantified how the distributions of arthropods were correlated with these oils.…”