From blackbirds and thrushes...to the gut-loaded cricket: a new approach to zoo animal nutrition

Abstract

Zoo animal nutritionists need to make decisions about diet composition for a wide variety of vertebrate species, including those with very specialized diets (dietary specialists). For some zoo species it is common to refer to the published literature on the nutrient requirements of analogous domestic animals, such as cattle, horses and cats, as well as human beings (Allen & Oftedal, 1996). When this information is combined with knowledge of natural history, feeding patterns, composition of foods consumed in the wild and gastrointestinal tract morphology, it is possible to develop a sound foundation for a successful feeding programme for many zoo animals.

Challenges with effective nutrient supplementation for amphibians: A review of cricket studies

“…To date, there are no established nutrient requirements for amphibians; target levels of nutrients are generally based on those for other species such as cats or rats [Finke, 2003;Hunt Coslik et al, 2009;Sullivan et al, 2012;Ferrie et al, this supplement]. Ideally, a dusted cricket would provide a Ca:P of 1:1-2:1 (on a dry matter basis DMB) [Allen andOftedal, 1982, 1989;Trusk and Crissey, 1987;Hunt et al, 2001] and/ or 1.5 mg/g (DMB) vitamin A [Sullivan et al, 2012]. Further exacerbating the situation is the variability inherent with dusting as live crickets have been shown to clean over 50% of dusted supplement off their bodies within 2.5 min of dusting [Li et al, 2009], and amphibians may not immediately consume their prey.…”

“…Gastrointestinal tract capacity varies among insect species and within age/ size categories of the same species, impacting the ability to which an insect can fill its digestive system with a gut loading diet [Hunt et al, 2001;Finke, 2003;Finke et al, 2005;Attard, 2013]. As a result, the relationship of dietary nutrients and nutrients in the bodies of insects can be species and/or age-specific [Allen and Oftedal, 1989;Allen, 1997;Attard, 2013].…”

“…is limited. Calcium and phosphorus (P) was the subject of most early supplementation studies and reviews [Allen andOftedal, 1982, 1989;Sabatini et al, 1998;McClements et al, 2003] while other researchers began to evaluate concentrations of vitamins such as A and E in crickets [Pennino et al, 1991;Barker et al, 1998;Sabatini et al, 1998;Attard, 2013]. Later studies investigated concentrations of retinol, retinal, and ß-carotene [Dierenfeld et al, 1995;Finke, 2003;Li et al, 2009;Ogilvy et al, 2011;Sullivan et al, 2012;Attard, 2013].…”

“…The nutrient concentration of feeder insects (e.g., crickets) can be impacted by a variety of factors, including but not limited to diet, husbandry and geographic location. Insects of the same species often show different nutrient concentration related to variations in these factors [Allen andOftedal, 1982, 1989;Attard, 2013]. In general, insect species, including crickets, contain inadequate levels of calcium and several other nutrients (including vitamin A) required by the animals to which they are fed [Allen and Oftedal, 1982;Bernard and Allen, 1997;Barker et al, 1998;Anderson, 2000;Finke, 2003;Finke et al, 2005;Hunt Coslik et al, 2009;Attard, 2013] As such, the challenge becomes finding a way to provide the insectivore a diet that has the potential to meet all of their (known or assumed) nutritional requirements.…”

“…While amphibians consume a wide variety of insect species in their natural habitats [Allen andOftedal, 1982, 1989;Pennino et al, 1991;Barker et al, 1998;Attard, 2013], replicating this diverse diet in managed environments often faces broad challenges including issues of environment, legality, economics, and practicality of insect husbandry. A lack of knowledge regarding nutritional requirements of amphibians and nutrient absorptive efficiency, contribute to the complexity of providing a balanced diet to managed amphibia.…”