Transit time and digestibility of two experimental diets in the maned wolf (Chrysocyon brachyurus) and domestic dog (Canis lupus)

Abstract

Recent research involving nutritional management of clinical disease secondary to cystinuria in captive maned wolves (Chrysocyon brachyurus) in the United States resulted in the production of a commercially manufactured maintenance diet and subsequently, a further modified experimental diet. These two diets differed only in their protein sources and sodium concentrations. The purpose of this study was to further investigate these diets by determining their digestibility and transit time in maned wolves, and also to compare these results to the digestibility and transit time of the diets in domestic dogs. The experiment consisted of two diets (maned wolf commercial maintenance diet and experimental diet) and two species (maned wolf and domestic dog [beagle]) arranged as a 2 Â 2 factorial design. For the transit time study, titanium dioxide (TiO 2 , 5 g/kg diet) was administered as a pulse dose and total collection of feces was carried out for 50 hr. There was no effect of diet or species on initial Ti recovery time (IRT), the amount of Ti recovered at IRT, or the time to reach 50% of Ti excretion in the feces. Maned wolves had lower total percent recovery (Po0.01) of Ti than dogs and shorter time to last recovery of Ti in the feces (Po0.05), however, marker excretion in the maned wolves may not have been complete. For the digestibility study, in which chromic oxide was used as a marker, fecal samples were collected on 2 consecutive days immediately after 12 days of being fed the diets and then analyzed for dry matter, energy, protein, and minerals. Crude protein, calcium, phosphorus, and zinc apparent digestibilities were unaffected by species or diet (P40.05). Apparent digestibility of dry matter (Po0.05) and energy (Po0.01) were higher in the experimental diet and in the dogs. Both dogs and maned wolves fed the maintenance diet exhibited a greater apparent retention of copper, iron, and magnesium (Po0.01). Dogs had a higher apparent retention of magnesium and sodium than the maned wolves.

Hunger mediates apex predator's risk avoidance response in wildland–urban interface

“…While a higher expected hunger level appears to accompany longer‐term (seasonal) energetic deficits, an extended hunger bout can occur at any time. We observed some hunger bouts extending longer than digesta passage time of large carnivores (Childs‐Sanford & Angel, ; Warner, ) (i.e. >5–10 days).…”

Demonstration of uniformity of calcium absorption in adult dogs and cats

“…If available, descriptions of diets such as protein source, high fat, lactose or bone content and conditions of housing and feeding, study duration and breed were noted. Relevant details on the studies included in the meta‐analysis are given in the Tables S1 (Tereg and Arnold, ; Malcolm, ; Steel and Gies, ; Kochmann, , ; Kochmann and Petzsch, ,b; Givens, , ; Givens and Mendel, ; McClugage and Mendel, ; Greenwald, ; Mayerson et al., ,b; Gross, ; Greenwald and Gross, ,b; Liu and McCay, ; Konishi and McCay, ; Drochner et al., ; Apel, ; Meyer and Mundt, ; Arndt, ; Koch‐Erhorn, ; Muehlum, ; Ingwersen, ; Lass, ; Struckmeyer, ; Zentek and Meyer, ; Habernoll, ; Beynen et al., ; Malafaia et al., ; Schuster, ; Childs‐Sanford and Angel, ) and S2 (containing papers on cats mentioned below).…”

“…In total, 35 papers and some unpublished data (personal communication Britta Dobenecker, Chair of Animal Nutrition and Dietetics, Ludwig‐Maximilians‐University Munich, Germany) met the inclusion criteria. 34 papers (Apel, ; Arndt, ; Beynen et al., ; Childs‐Sanford and Angel, ; Drochner et al., ; Givens, , ; Givens and Mendel, ; Greenwald, ; Greenwald and Gross, ,b; Gross, ; Habernoll, ; Ingwersen, ; Koch‐Erhorn, ; Kochmann, , ; Kochmann and Petzsch, ,b; Konishi and McCay, ; Lass, ; Liu and McCay, ; Malafaia et al., ; Malcolm, ; Mayerson et al., ,b; McClugage and Mendel, ; Meyer and Mundt, ; Muehlum, ; Schuster, ; Struckmeyer, ; Tereg and Arnold, ; Zentek and Meyer, ) and some unpublished data contained full data for Ca, whereas only 28 contained full data for P (Arndt, ; Beynen et al., ; Childs‐Sanford and Angel, ; Drochner et al., ; Givens and Mendel, ; Greenwald, ; Greenwald and Gross, ,b; Gross, ; Habernoll, ; Ingwersen, ; Koch‐Erhorn, ; Kochmann, , ; Kochmann and Petzsch, ,b; Lass, ; Liu and McCay, ; Malafaia et al., ; Mayerson et al., ,b; Meyer and Mundt, ; Muehlum, ; Steel and Gies, ; Struckmeyer, ; Tereg and Arnold, ; Zentek and Meyer, ). This data set accounted for 438 individual digestion trials, but due to incomplete recording in the published papers some of the trials we...…”

Digestibility of two diet items by captive eastern quolls (Dasyurus viverrinus)

“…Compared to similar sized eutherian carnivores maintained on natural food items (digestibility values range 71–99%), the eastern quoll had similar apparent total tract digestibility values for most nutrients studied (Table ). Eutherians maintained on artificial diets (that in some cases are plant‐based) can exhibit lower values than the quolls, for example, digestibility of DM and protein ranges 65–75% in the maned wolf ( Chrysocyon brachyurus ) [Childs‐Sanford and Angel, ]. Quolls' protein digestibility was 95–98% whilst that of eutherians ranged from as low as 73–97% on both natural and artificial diets [Moors, ; Crissey et al, ; Ahlstrøm and Skrede, ; Childs‐Sanford and Angel, ; Bennett et al, ; Kerr et al, ] (Table ).…”