Fiber Digestibility by the Orangutan (Pongo Abelii): In Vitro and in Vivo

Abstract

Limited nutritional information exists on diets of free-ranging orangutans, Pongo abelii and P. pygmaeus. Although they are classified as frugivores, the chemical composition of their diet and their gastrointestinal anatomy suggest that they rely on fiber fermentation for a substantial portion of energy. However, the extent to which they can ferment fiber is not known. Continuous culture systems, inoculated with orangutan fecal bacteria, were established to determine the fiber-digesting capacity of orangutan hindgut microflora. The cultures received one of four treatments: soybean hulls, ground corncobs, corn starch, or no food. Neither dry matter nor neutral detergent fiber digestibilities differed significantly among treatments. However, neutral detergent fiber digestibilities were high for both the soybean hull (88.4%) and ground corncob (86.1%) treatments, indicating that the microflora had a strong fibrolytic capability. To determine whether the same fiber-degrading capacity occurred in vivo, two adult orangutans and one juvenile were fed four gel-matrix diets containing soybean hulls, ground corncobs, or ground primate biscuits. Neutral detergent fiber concentrations (dry matter basis) of the gel matrices were 52.9% with soybean hulls, 46.8% and 63.7% with ground corncobs, and 31.3% with ground primate biscuits. A fifth diet consisted of primate biscuits with 27.3% neutral detergent fiber (dry matter basis) and was considered the baseline diet. Neutral detergent fiber digestibility (74.5%) was greatest (P < 0.05) for the soybean hull gel diet and least (57.5% and 45.0%, respectively; P < 0.05) for the 63.7% neutral detergent fiber (dry matter basis) corncob gel diet and the baseline primate biscuit diet. Total volatile fatty acid concentrations in orangutan feces were not significantly different among diets; however, molar proportions of acetic, propionic, and butyric acid differed (P < 0.05) among diets. The results from both studies indicated that orangutans are capable of extensive fiber fermentation.

In Vitro Fermentation of Dietary Carbohydrates Consumed by African Apes and Monkeys: Preliminary Results for Interpreting Microbial and Digestive Strategy

“…For example, butyrate may be absorbed via a Na + /H + and or a K + /H + exchange and -in colon fermentersserves as an ATP source for colonic epithelial cells (Backhed et al 2005;Bergman 1990;Milton 1998;Milton and McBee 1983). However, despite the fact that SCFAs contribute substantially to a primate's energetic balance, with notable exceptions (Campbell et al 2002;Clemens and Phillips 1980;Milton and McBee 1983;Schmidt et al 2005;Ushida et al 2006), microbial metabolism and it impact on wild, nonhuman primate feeding biology and digestive strategy remain poorly described.…”

Orangutan Energetics and the Influence of Fruit Availability in the Nonmasting Peat-swamp Forest of Sabangau, Indonesian Borneo

“…Unfortunately, fiber digestibility trials have yet to be performed on wild orangutans, which include more indigestible lignin in their diet (ConklinBrittain et al 2006;Knott 1999). As such, we favor the NDF digestion coefficient of 54.3% determined for captive chimpanzees (Milton and Demment 1988), as 1) this value is lower than that determined for captive orangutans (Schmidt et al 2005), in accordance with the higher lignin content of wild diets; 2) this value has been used previously for calculating energy content in wild orangutans and chimpanzees (Conklin-Brittain et al 2006), and is thus directly comparable to these measures; and 3) the low daily energy intake rates reported below for Sabangau orangutans indicate that high fiber digestion ability is crucial for orangutans, at least in Sabangau. Thus, the PFV used for NDF is 3 Â 0:543 ¼ 1:6 kcal=g 7 kJ=g ð Þ.…”

“…Since NDF is mostly hemicellulose and cellulose, which are carbohydrates, the PFV for TNC could theoretically be applied, but gut microbes typically take 1 kcal/g for themselves, leaving 3 kcal/g for the consumer (Conklin and Wrangham 1994;van Soest 1994). Comparisons of fiber contents in the foods consumed and feces of captive orangutans (Schmidt et al 2005), chimpanzees (Milton and Demment 1988), and western gorillas (Remis 2002), respectively, yielded fiber digestion coefficients of 59.4%, 54.3%, and 57.5%. These test subjects were fed diets containing 44%, 34%, and 30% NDF, respectively, which is broadly similar to wild diets, but with lower lignin levels.…”

Dietary Fibre Fractions in Cornelian Cherry Fruit ( Cornus Mas L.)

“…Z badań Schmidta i wsp. [24] wynika, że najmniejsze ilości tej frakcji zawierają zielone winogrona (3,27 g/100 g s.m. ), a najwięk-sze -melony (22,04 g/100 g s.m.).…”

“…W odmianach Golden Glory, Paczoski, Słowianin i Bolestraszycki w roku 2007 oznaczono około 2-krotnie więcej frakcji ADF niż w roku 2008, co może wynikać z różnych warunków pogodowych w analizowanych latach. Pod względem zawartości frakcji ADF, podobnie jak w przypadku frakcji NDF, owoce derenia można porównać do czarnych jagód (czyli borówki czernicy), grejpfrutów, kiwi, pomarańczy i arbuzów [24].…”