A COMPARATIVE STUDY OF IRON ABSORPTION IN MYNAH BIRDS, DOVES AND RATS1G.M. Dorrestein1* A. Mete1, J.J.M. Marx2, I. Lemmens3, and A.C. Beynen4
1Dept. Vet Pathology, Section Exotic Animals and Wildlife, Yalelaan 1, 3584 Cl Utrecht, The Netherlands; 2 Medical Faculty, Dept. of Internal Medicine, UMC, 3Dept. of Animal Health and Nutrition, 4Dept. of Laboratory Animal Science, Utrecht University, Utrecht, The Netherlands.
To compare the three steps of iron absorption, uptake, transfer and retention after a single dose application in different species fed on two levels of dietary iron.
Materials and methods
The animals consisted of 12 rats (Rattus norvegicus), 12 doves (Streptopelia d. decaocto) and 12 mynahs (Acridotheres t. tristis and Gracula r. religiosa). They were fed pellets containing low and high levels of iron (low iron diet (LID): 90 ppm iron, and high iron diet (HID): 570 ppm iron) for at least 2 weeks. The absorption and retention of iron from an oral test dose of 50 mg Fe (labeled with markers 59Fe and 51Cr) was measured using the whole -body gamma counter. Measurements were conducted on days 1, 2, 4, 7 and 14.
Results Differences within and between species were determined for mucosal uptake, transfer and retention. Mynahs had the highest retention values among the studied species (48% for LID and 23% for HID). The results were significantly different (P< 0.02) within species for the two dietary groups, and among the other two studied species (34% -LID and 17% -HID in the rats, and 12% -LID and 3% -HID in the doves).
Mynahs have higher uptake and retention of iron when compared to rats and doves. All studied species have a regulatory mechanism for iron absorption but this mechanism seems much less effective in mynahs. When doves are considered as the reference species, based on our findings, the rats would normally need 26-41 ppm, and mynahs 19-25 ppm of iron in the diet. 1 Presented at the 18th Meeting of the ESVP, September 19-22, 2000. Amsterdam (NL)
THE ROLE OF SEASONALITY IN THE DIET OF RODENTSM.J.R. Jordan
Animal Management Section, Sparsholt College Hampshire, Sparsholt, Winchester, Hants. SO21 2NF
For many species of rodent the recorded diets in the wild comprise a wide range of food items. This is often interpreted as being an indication of their generalist nature and this may be true of a number of species, especially ubiquitous pests such as Western House Mouse (Mus domesticus) or Brown Rat (Rattus norvegicus), which are able to simultaneously utilise a variety of foods in a single habitat. However for many other species the broad range of items consumed actually represents a changing sequence of diet through the year and a corresponding sequence of specialist foraging behaviour. Thus the species should perhaps be viewed as highly adaptable and changing specialists rather than non-specialised generalists.
The reasons for this sequential specialisation through the year are still poorly understood for many species. For some this seasonally changing specialisation may be as a direct consequence of changing resources and an enforced response to a constantly varying habitat. For others though, evidence suggests that the sequential changing represents an active shift in diet initiated by the animals themselves. This active shift may well be important in influencing or cueing a number of events in the annual cycle of such species, particularly reproduction and hibernation. A number of plant compounds have been proven to influence reproductive success in rodents or provide threshold levels which have to reached in order for reproduction to commence. Thus the feeding of appropriate food items at specific times of the year in captivity may well be important in maintaining normal annual and reproductive cycles in some species.
DIET AND NUTRITION OF PIED TAMARINS Saguinus bicolor bicolor AT JERSEY ZOOK. Foster*, A.T.C. Feistner and D. Wormell
Durrell Wildlife Conservation Trust, Les Augrès Manor, Trinity, Jersey JE3 5BP, Channel Islands, British Isles
The pied tamarin, Saguinus bicolor bicolor, is considered to be the most threatened Amazonian primate because of its restricted range in the wild. This makes the captive population an important safety-net, although there have been difficulties with breeding and maintaining them in captivity. Pied tamarins at Jersey Zoo and elsewhere have suffered from low infant survival, premature and stillbirths, chronic diarrhoea, wasting marmoset syndrome and metabolic bone disorders. These problems may be linked in part to diet, so a nutritional study was carried out at Jersey Zoo (which holds the bulk of the EEP population) in order to investigate whether the tamarins are being provided with, and are consuming, a diet with the correct balance of nutrients. In the wild, pied tamarins consume insects, fruit and plant exudates. They are known to have high protein and vitamin D3 equirements. The diet currently provided consists of high-protein pellets, fruit, vegetables, and protein items such as waxmoth larvae, locusts, egg, cat food, cheese and nuts. Gum arabic is provided for additional energy and calcium, which is particularly important for breeding females. Citrus fruits are restricted in the diet as they are potential irritants, increasing the occurrence of diarrhoea. The diet was quantified by weighing the amount of each food item provided in each feed per group (n=8) per day. Feed remains were collected later the same day in order to calculate the amount of food that had been consumed per enclosure, and then allowing the estimation of food consumption per individual and per kilogram body mass. Control feeds were used to calculate the weight change that was due to water loss or gain. The diets were analysed for nutrient content using the Zootrition software (Wildlife Conservation Society, 1999). These nutritional compositions were then compared to requirements for New World monkeys. Zootrition was also used to analyse the composition of the food items provided to the tamarins in order to establish the nutrient levels in each food. This is useful for adjusting the diet and/or replacing food items. The diet analysis should provide some insight into why there are health and breeding problems with pied tamarins and result in recommendations for adjusting nutrient levels. Jersey Zoo has recently produced management guidelines for pied tamarins and dietary analysis can contribute to these, in addition to the feeding practises and enrichment aspects. These are an important part of dietary management, in addition to straight nutrient composition. Nutritional studies both in captivity and in the wild are important tools in the conservation of this critically endangered primate. The contribution of the captive breeding programme can be maximised if well-balanced diets support maintenance and breeding of healthy individuals.
DISTRIBUTION OF FOOD IN SPACE AND TIMEC. Schwitzer*, W. Kaumanns and K. Hampe
Zoologischer Garten Köln, AG Primatologie, Riehler Str. 173, 50735 Köln, Germany
In the wild, primates usually spend a large proportion of their active time foraging and feeding. Access to food and food intake are influenced by individual factors (e.g. the physiological abilities of the animal) and social factors (e.g. dominance hierarchies), and especially by the availability of food and its distribution in space and time. This paper focuses on the latter aspect. Food resources in the wild may be scarce and widely distributed throughout the animals home ranges, and certain food types may be available only during limited periods of the year. Ideally, feeding primates in captivity should include such a varied food distribution, both spatially and temporally. However, the captive conditions often do not allow to realise this. Spreading out food can only be done within the limits of the animals enclosure. Moreover, it is rarely feasible to feed more than three or four times a day, as there is not enough staff available. Also, the zoo-day is usually not more than eight hours long (depending on the working times of the keepers). In most zoos there is a certain degree of daily variation in foodstuffs fed, whereas a seasonal variation is more or less non-existent in captivity. Availability and distribution of food in space and time are main factors for the regulation of food intake. Not only do they regulate the amount of food consumed within a certain time period (e.g. per day), but also influence the patterning of nutrient and energy intake during this period. It is assumed that the latter aspect is critical for an optimal (species-specific) functioning of satiation processes. Ideally, optimal feeding schedules should be developed with reference to foraging data from the field. The latter, however, are rarely available. The aim of this paper is to analyse relevant studies and to work out a tentative concept on how optimal energy and nutrient intake could look like.
STATUS OF NUTRITION WITHIN EEP HUSBANDRY GUIDELINESS - CAN WE HELP?J. Nijboer1, A.L. Fidgett2*, J-M. Hatt3, A.A. Macdonald4 and W. van der Horst1
1Veterinary Department, Rotterdam Zoo, Van Aerssenlaan 49, 3039 KE Rotterdam, The Netherlands; 2Faculty of Biological and Life Sciences, University of Glasgow, G12 8QQ, UK; 3Division of Zoo Animals and Exotic Pets, University of Zurich, Winterthurerstrasse 260, CH-8057, Zurich Switzerland; 4Department of Preclinical Veterinary Sciences, Royal (Dick) School of Veterinary Studies, University of Edinburgh, Summerhall, Edinburgh, EH9 1QH, UK.
Many modern zoos have agreed to work together focussing their conservation efforts on endangered species and establishing breeding programs for these animals. In Europe these projects are called EEPs (European Endangered Breeding Programmes) and one of the responsibilities of EEP oordinators is to develop husbandry guidelines, aiming to achieve optimal conditions for well-being and reproduction of all the animals in the programme. An essential component of any animals husbandry is what it should be fed and guidelines should therefore contain a section on feeding, summarising the diet consumed both in-situ and ex-situ, any special dietary requirements, handrearing protocols, nutrition-related health problems and a bibliography. A preliminary investigation in August 2000 found that less than half of the checked EEP guidelines presented adequate advise on the nutrient requirement of the species. A questionnaire was devised with two primary aims; i) to gather up and make more widely available information on all the existing husbandry manuals and ii) stimulate their improvement by encouraging the inclusion of nutritional information in a standardised format. The questionnaire was sent to the Co-ordinator or Chair of the 125 EEPs, 32 Taxon Advisory Groups (TAGs) and 68 approved European Stud Books (ESBs) listed in the 1989/99 EEP Yearbook. Many co-ordinators have already asked for support in compiling the nutrition section of guidelines and the information collated from the questionnaire will reveal where the major gaps in nutritional knowledge lie. Plans are in progress for nutrition workshops and help sessions to be scheduled during the EAZA/EEP meeting later this year. Furthermore, Species survival Programmes (SSPs), the North American equivalent to EEPs, are undergoing a similar review process and the results can be compared to determine areas of overlap and/or potential exchange of expertise. Simply considering the nutrition of EEP species may ultimately have a wider impact within the zoo community. Nearly all zoos spend 3-6 % of their budget on food for their animals. The payment of more attention to the ingredients being fed could reduce this cost and improve the nutrition, mainly by simplifying the diet. Often feeding a simpler range of items will result in a better and more consistently balanced diet and ultimately, less obese zoo animals. Simplification of diets will reduce the amount of labour involved in food preparation, which may reduce expenditure but will also free p
time for keepers to devote to other important aspects of animal husbandry, enrichment for example.