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This study examined the spatial defecation patterns of numbats within captivity and tested the efficacy of a food colorant as a fecal marker in this species. Rather than randomly distributing scats throughout their environment, the numbats aggregated their feces at specific sites forming latrines. It is unclear whether the strong inclination for latrine formation was due to this species' inherent behavior or is a direct result of captivity. Males were found to have a higher daily defecation rate, different defecation time, larger number of latrines, and greater number of scats per quadrant, as compared to females. In this study, the majority of scats were deposited along enclosure boundaries and for both sexes there was a higher probability of latrines being placed along enclosure fencing shared with a female neighbor. The high concentration of latrines along boundaries suggests that they may play a role in territorial defense. The results also indicated that captive numbats tend to choose defecation points away from food and refuge sites. Transit and total retention time of the marker through the GIT was ≤3 hr and between 24 and 27 hr, respectively. A marker dose of 3 gtts feed−1 × 2 feeds day−1 was required to reach a steady and detectable state of marker output, which enabled accurate identification of individual samples during the breeding season. Reliable labeling was obtained using blue and red colored food dye, and there was no evidence that incorporation of the marker into the diet had any negative effects on food intake. Zoo Biol. 32:324-331, 2013. © 2013 Wiley Periodicals Inc. [ABSTRACT FROM AUTHOR]

Objectives: The aim of this study was to investigate how a moderate increase in dietary meat content combined (or not) with soluble fibre would influence protein digestion as well as digesta characteristics and flow. Methods: Four groups of pigs were fed Western-style diets (high-protein/high-fat) containing two types of barbecued red meat, one with and one without a wheat arabinoxylan-rich fraction. After 4 wk, digesta samples were collected from small and large intestinal sites and analyzed for protein, amino acids, dry matter, and acid-insoluble ash. Tissue samples were also collected from each site. Results: Arabinoxylan consumption led to somewhat lower apparent protein digestibility within the small and large intestines as well as shorter mean retention times. This suggests that the lowered protein digestibility is due, at least partly, to shorter access time to digestive proteases and absorptive surfaces. Additionally, digesta mass was higher in pigs fed arabinoxylan while dry matter (%) was lower, indicating an increased digesta water-holding capacity due to the presence of a soluble dietary fiber. Conclusion: Data showed that solubilized wheat arabinoxylan provides potential health benefits through decreased protein digestibility, increased digesta mass, and reduced mean retention time, even for diets with a moderately higher protein content. These factors are associated with efficiency of digestion and satiety, both of which have implications for prevention of obesity and other health disorders. [ABSTRACT FROM AUTHOR]

Testosterone secretion in mammals typically occurs in random pulses such that a single blood sample provides limited information on reproductive endocrine status. However, it has been shown in several species that an index of the prevailing testosterone biosynthetic capacity of the testes can be obtained by measuring the increase in circulating testosterone after injection of a GnRH agonist or human chorionic gonadotrophin (hCG). Hence, the aims of the present study were to examine fluctuations in testosterone secretion in the koala (n = 6) over a 24-hour period and then characterise testosterone secretion after injection of the GnRH agonist buserelin (4 micro g) or hCG (1000 IU). The latter was used to establish an index of the prevailing testosterone biosynthetic capacity of the koala testis. Individual koalas showed major changes in blood testosterone concentrations over 24 hours, but there was no apparent diurnal pattern of testosterone secretion (P > .05). Injection of buserelin and hCG resulted in an increase (P < .05) in blood testosterone concentration. After injection of exogenous hormone, near maximal concentrations of testosterone occurred at around 60 minutes. There was a tendency for plasma testosterone to decline after 90 minutes with buserelin, but concentrations remained close to the upper limit for 240 minutes with hCG. There were strong positive correlations between the average testosterone concentration over 24 hours and the maximum observed testosterone concentration after stimulation with GnRH and hCG (GnRH, r = .772; P = .07 and hCG, r = 1.0; P < .01). The findings in the present study confirmed that individual male koalas can show large fluctuations in blood testosterone concentrations over time and that a GnRH agonist and hCG can be used in the koala to obtain an index of the prevailing steroidogenic capacity of the testes.