Gum is a widely available carbohydrate,composed mainly of non-digestible structural carbohydrates.No mammalian enzymes can digest gum;therefore,a mammal ingesting gum must rely on microbial fermentation to access the ...Gum is a widely available carbohydrate,composed mainly of non-digestible structural carbohydrates.No mammalian enzymes can digest gum;therefore,a mammal ingesting gum must rely on microbial fermentation to access the energy it possesses.Gums are relatively nutrient poor.Despite this,some mammals have evolved to exploit this food resource.We aim to review the literature for all mammal species which have been recorded to ingest gum,whether quantified or not,and discuss this in the context of their evolutionary adaptations.We also investigated the recommended captive diets for these species to look at whether gum is recommended.We conducted a literature search on ISI Web of Knowledge to tabulate all mammal species observed ingesting gum and classified them as obligate,facultative or opportunistic feeders.We encountered 94 mammal species that eat gum in the wild(27 obligate feeders,34 facultative feeders and 33 opportunistic feeders).Obligate feeders have entirely evolved to exploit this resource but were found to not be given gum in captivity,which may explain why they are failing to thrive,as opposed to facultative feeders,which have fewer issues.Gum may be necessary for the health of obligate feeders in captivity.Future research should focus on the physiological effects that gum ingestion poses on different digestive systems.展开更多
Pandas are endemic to iodine-poor environments and appear to be specialized for a goitrogenic staple diet.In particular,the importance of thiocyanate in bamboos might possibly have been overlooked in captive breeding ...Pandas are endemic to iodine-poor environments and appear to be specialized for a goitrogenic staple diet.In particular,the importance of thiocyanate in bamboos might possibly have been overlooked in captive breeding programs.Although excreted in urine,thiocyanate first antagonizes absorption of iodine by the thyroid(of parent,fetus and suckling juveniles)and the mammary glands.In livestock and humans,subclinical deficiency of iodine is known to result in reproductive problems(including retardation of the fetus and suckling infant)even where the mother appears to be unaffected beyond slight hyperplasia of the thyroid and subtle hypothyroidism as reflected by levels of thyroid hormones.We suggest that the possibilities of iodine deficiency or excess should be carefully considered wherever the reproductive rates of pandas are unsatisfactory.展开更多
基金We would like to thank the Longleat Safari and Adventure Park,the Whitley Wildlife Conservation Trust,the Primate Society of Great Britain and the International Primatological Society Captive Care Working party,the Nacey Maggioncalda Foundation,the University’s Federation for Animal Welfare,National Geographic(GEFNE101-13),the People’s Trust for Endangered Species,the Disney Worldwide Conservation Fund,Colombus Zoo,the Phoenix Zoo,the Cleveland Zoo and Zoo Society,the Shaldon Wildlife Trust,the Shepreth Wildlife Park,the Sophie Danforth Foundation,the Conservation International Primate Action Fund,and Mazuri Zoo Feeds for their funding support with various elements of this ongoing research.We are also thankful to Dr J.G.Lee and to 3 anonymous reviewers for improving the quality of the manuscript.
文摘Gum is a widely available carbohydrate,composed mainly of non-digestible structural carbohydrates.No mammalian enzymes can digest gum;therefore,a mammal ingesting gum must rely on microbial fermentation to access the energy it possesses.Gums are relatively nutrient poor.Despite this,some mammals have evolved to exploit this food resource.We aim to review the literature for all mammal species which have been recorded to ingest gum,whether quantified or not,and discuss this in the context of their evolutionary adaptations.We also investigated the recommended captive diets for these species to look at whether gum is recommended.We conducted a literature search on ISI Web of Knowledge to tabulate all mammal species observed ingesting gum and classified them as obligate,facultative or opportunistic feeders.We encountered 94 mammal species that eat gum in the wild(27 obligate feeders,34 facultative feeders and 33 opportunistic feeders).Obligate feeders have entirely evolved to exploit this resource but were found to not be given gum in captivity,which may explain why they are failing to thrive,as opposed to facultative feeders,which have fewer issues.Gum may be necessary for the health of obligate feeders in captivity.Future research should focus on the physiological effects that gum ingestion poses on different digestive systems.
文摘Pandas are endemic to iodine-poor environments and appear to be specialized for a goitrogenic staple diet.In particular,the importance of thiocyanate in bamboos might possibly have been overlooked in captive breeding programs.Although excreted in urine,thiocyanate first antagonizes absorption of iodine by the thyroid(of parent,fetus and suckling juveniles)and the mammary glands.In livestock and humans,subclinical deficiency of iodine is known to result in reproductive problems(including retardation of the fetus and suckling infant)even where the mother appears to be unaffected beyond slight hyperplasia of the thyroid and subtle hypothyroidism as reflected by levels of thyroid hormones.We suggest that the possibilities of iodine deficiency or excess should be carefully considered wherever the reproductive rates of pandas are unsatisfactory.
