Evaluation of the nutritional status of rehabilitated green sea turtles (Chelonia mydas) utilizing nutritional markers, stable isotopes, and metagenomics

Green sea turtles (Chelonia mydas) are unique because hatchlings and pelagic juveniles are carnivorous, while later life history stages are primarily herbivorous. Dietary requirements at each life stage are poorly understood, making diet selection during rehabilitation of injured and sick animals challenging. Although turtles are typically transitioned to an herbivorous diet before release, food items high in animal protein (e.g.,...

Apple leaves and bark as browse items for herbivorous monogastrics under human care

Many zoological institutions are faced with challenges when developing and providing a diet for their non-ruminant browsing herbivores. The most prominent issue remains providing readily available, safe and sufficient quantities of plant material. Zoos are often forced, usually by climate, to utilize seasonally available, local, appropriate and or novel plant species in order to decrease the effort and expense required...

Application of non-ruminant herbivore nutrition

The nutrition of the horse has perhaps been studied more than the nutrition of any other non-ruminant herbivore. Information about the nutrition of the horse may be of value when formulating diets of some wild non-ruminant herbivores. Of course, quantitative nutrient requirements developed for the horse must be used with caution for other animals, if at all. Knowledge of energy,...

Thermal constraints on grazing and browsing herbivores

There are five ways in which an animal may exchange heat with its environment: solar (shortwave) radiation gain, longwave radiation exchange, convective exchange, conductive exchange, and heat loss by evaporation. This heat exchange, in combination with the metabolic heat produced by the animal, defines the animal’s heat balance (Figure 1). When a homeothermic animal cannot lose sufficient body heat (generated...

Implications of carbohydrate feeding for captive herbivore nutrition and welfare

Carbohydrates comprise the major portion of most herbivore diets. Research is limited regarding the effect of carbohydrates as provided in commercial feeds, forage, and browse on the nutrition and health of captive herbivores. However, the diversity of carbohydrates, their digestion characteristics, nutrients they supply, impacts of their physical form, and potential impact on animal health strongly recommend that they be...

The effect of tannin on the in vitro solubilization of iron

The absorption of dietary iron can be greatly influenced by other constituents in the diet, such as ascorbic acid (vitamin C) and tannins. Ascorbic acid increases the bioavailability of iron by converting Fe3+ to Fe2+, while tannins can reduce the bioavailability of iron by binding to it. Captive herbivorous animals are often impacted by either the addition or absence of...

The interaction between factors that affect the daily time spent grazing by ruminants

The animal-plant interaction between grazing ruminants and the grasses and forbs that make up temperate pasture swards is complex. The interaction is ultimately expressed in each mouthful of herbage (bite) ingested by the grazing animal. Each bite is characterised by quantity (bite weight), quality (species composition, plant part, plant maturity), and the time taken to apprehend, crop, chew and swallow...

Evolution of diets for Herbivorous and Omnivorous Reptiles at the Philadelphia Zoo: From Mystery Toward Science

At the Philadelphia Zoo the diets for herbivorous and omnivorous reptiles evolved over a period of years. Prior to 1992. the diets had been formulated solely by the former curator. Analysis of the general salad fed to smaller species of herbivorous and omnivorous reptiles (Animal Nutritionist – N-2) indicated unbalanced levels of fat-soluble vitamins. In addition. one of the salad’s...