General subjects

Gross Energy and nutrient content of reptilian eggs

J. Mos, J.Erinkveld, D.Kuiper, T.R.Huisman

Department of Animal Management, Van Hall Instituut, Leeuwarden

Reptilian eggs can be considered as packages loaded with energy and nutrients. Producing these packages requires nutritional support. To give a sound nutritional advice for reproducing reptiles one needs to know the nutritional contents of eggs in the first place. Surprisingly enough there are not many data on this subject.
From January until June 2004, 24 reptile egg clutches or parts thereof were collected from 15 different species in total. From these clutches 158 eggs were analysed for Gross Energy (GE), Dry Matter (DM), Ash, Crude Protein (CP), Calcium (Ca), Phosphorus (P) and Magnesium (Mg). Methods used were Bomb Calorimetry, Proximate Analysis and Atomic Absorption Spectroscopy. Crude Fat contents were calculated by difference. Egg contents and shells were separately analysed.
The average GE values for egg contents varied from 25.1 kJ/g DM to 28.5 kJ/g DM. Soft egg shells contained on average 15.6 kJ/g DM. The energy content of hard egg shells could not be determined.
The Crude Protein percentage of the egg contents varied from 40% to 58%. Crude protein in shells varied from 62% in soft shells to 11.7% in hard shells.
In soft shelled eggs calcium values in the egg contents averaged 13 mg/ g DM. In hard shelled eggs it averaged 4.8 mg/ g DM. Calcium content in soft egg shells averaged 105 mg/ g DM and in hard egg shells 370 mg/ g DM.
Before these results can be translated into a dietary advice more insight is necessary in the reproductive physiology of reptiles. How and in what time the eggs develop in the reptilian body; are energy and nutrients necessary for egg development directly taken from food or from body supplies; and what is the best moment to support egg development nutritionally - these are questions which are worthwhile to answer in future research. But also the relatively small database developed in this project needs further extension.

Author’s address:
T.R. Huisman
Van Hall Instituut
Agora 1
8901 BV Leeuwarden
The Netherlands

Developing nutrition standards and dietary guidelines for polar bears in captivity

B. Lintzenich1, A. Ward2, M. Edwards3

1Daniel F. and Ada. L. Rice Conservation Biology and Research Center, Brookfield Zoo, Brookfield, USA, 2Fort Worth Zoo, TX USA, 3Zoological Society of San Diego, CA, USA

Many factors should be considered when developing nutrition guidelines for captive polar bears. A discussion of nutrition issues took place at the polar bear husbandry conference hosted by Polar Bear International in San Diego, California in February 2004. From that conference a nutrition task force was developed that included SSP/Tag advisors, feed manufacturing nutritionists and husbandry specialists. Polar bear husbandry nutrition guidelines are in development with topics that encompass foraging ecology and general feeding recommendations including, diet proportions, food handling, dental issues, special needs, and proposed nutrient requirements. Additionally, fecal characteristics, seasonal weight fluctuations, and myths/lore will be addressed.
The polar bear (Ursus martimus) the most carnivorous of the Ursidae family, prey on primarily on ringed seals (Best, 1985; Briggs, 2002; Derocher, et. al, 2000; Stirling and Archibald, 1977). Other seal species (bearded, harp), some whale species (white, narwhal), walrus, reindeer, sea birds, carrion, and vegetation have been reported as consumed (Derocher, et al. 2000; Knudson, 1978; Russel, 1975). The polar bear, like many other bear species, is subject to seasonal periods of fast due to low food availability and have evolved physiological adaptations for periods of starvation (Cattet, 1990; Derocher, et al. 1990). The stomach of ursids are simple, and the distal segment of their intestine is marked only by an appearance of mucosa with no cecum present (Stevens and Hume, 1995). Most free-ranging adult polar bears typically consume the skin and the blubber of their prey, leaving the muscle and organs in order to optimize efficient use of energy and nutrients in the prey (Best, 1985). In contrast to the seasonal variation of the diet in the free-ranging bears, the captive polar bear in many zoos is fed throughout the year on a constant ration. The basic diet consists of commercial omnivore diet or dog food, in combination with a variety of other foods including frozen, thawed meat and fish, fruits, vegetables, and vitamin & mineral supplements. Food category proportions will be recommended. This will include food used in training and behavioral enrichment as well as browse forage items. Food handling and sanitation guidelines will be summarized. Dental issues were discussed with the Veterinary advisors. Rather than limit food choice, a list ranking foods’ effect on dental health is planned. Recommendations for will be outlined for overweight, geriatric, pregnant/lactating, and growing animals. Disease states related to diet will be outlined by the veterinarians. No species specific requirements are known for polar bears so other domestic models (cat and dog) and published research papers were applied to develop a model for use. Fecal characteristics were developed for the bear intake study conducted by the bear TAG nutrition advisors in 1996. These characteristics will be refined and guidelines developed. The nutrition advisors are examining weight data from various institutions for correlations with average temperature, latitude, and photoperiod for those locations across seasons. Finally, a list of myths and lore were outlined by the husbandry advisors from the bear TAG that included low vitamin A in captive diet compared to wild diet related to reproductive rates and coat problems, the questions of whether salt and thiamin/vitamin E supplements are necessary for captive bears, vitamin D and calcium supplementation for pregnant/lactating bears due to fractures in cubs, the addition of fat due to improper hair coat, protein and carbohydrate variation in diets related to seasonal changes in the wild diet, and general feeding carcass in captive diets.

· Best, R.B. 1985. Digestibility of ringed seals by the polar bear. Can. J. Zool. V:63:1033-1036.
· Briggs, M.B. 2002. Polar Bears, In: CRC Handbook of Marine Mammals Medicine: Health, Disease, and Rehabilitation. Pp. 989-1007.
· Cattet, M. 1990. Predicting nutritional condition in black bears and polar bars on the basis of morphological and physiological measurements. Can. J. Zool. V. 68:32-39.
· Derocher, A.E., R.A. Nelson, I. Sterling, and M.A. Ramsey. 1990. Effects of fasting and feeding serum urea and serum creatinine levels in polar bears. Marine Mam. Sci. 6(3):196-203.
· Derocher, A.E., O. Wiig, and G. Bangjord. 2000. Predation of Svalbard reindeer by polar bears. Polar Biol. 23:675-678.
· Knudson, B. 1978. Time budgets of polar bears (Urus maritimus) on North Twin Island, James Bay, during summer. Can J. Zool. 56:1627-1628.
· Russell, R.H., The Food habits of Polar bears of James Bay and Southwest Hudson Bay in summer and autumn, pp117-128.
· Stephens, C.E. and I.D. Hume. 1995.Comparative Physiology of the Vertebrate Digestive System. Second Ed. Cambridge University Press. New York, NY.
· Stirling,I., Archibald,W.R., 1977. Aspects of predation of seals by polar bears. J.Fish.Res.Board Can, Vol 34,pp1126-1129.

Author’s address:
B. Lintzenich.
Zoo Nutrition Services
Brookfield Zoo
3300 Golf Rd.
Brookfield, IL 60513

Survey of major nutrients in Asian Elephant (Elephas maximus) milk during different stages of lactation

S. Kölbl1, M. FlÒgger2, C. Kunz 3, J. Peter-Katalinić1, G. Pohlentz1

1Department of Biomedical Analysis, Institute for Medical Physics and Biophysics, University of MÒnster, Germany, 2Tierpark Hagenbeck, Hamburg, Germany, 3Institute for Nutrition Science, University of Giessen, Germany

Experiences made in different zoos showed considerable difficulties with the artificial rearing of elephant calves born in captivity. Besides loose stools or diarrhea, e.g. skin dryness and umbilical infection seem to be more likely in hand-raised calves. Therefore - and to prevent other nutrition-dependent stressors – it is necessary to provide a milk replacer which closely resembles the nutrient composition of the dam’s natural breast milk.

Milk is the sole food for infants during the first six month. It is well known that calves are milk-dependent for the first two years and will often suckle to the age of four or five. After the age of two the volume of the consumed milk begins to decrease gradually.
The makeup of natural milk is extremely complex and in most species the milk composition changes during lactation. In order to achieve a successful hand-rearing it is necessary to optimise the formula over the whole period of lactation. Therefore as much information as possible is required about the milk composition during different stages of lactation.

Since up to date only a few data on milk composition during the whole lactation time of elephants are available we started our project in cooperation with Tierpark Hagenbeck, Hamburg, Germany. Up to now we analysed the mature milk of one Asian elephant taken during early (51-274 days post partum; every four weeks, samples taken on three consecutive days, n=24) and late (4.5 years post partum, previous calves lactation, n=3) lactation for major nutrients. The content of protein was determined according to the method of Lowry, total lipids gravimetrically, and lactose by use of a β-galactosidase/glucoseoxidase test.

Although no dramatic changes could be observed from the 2nd to the 9th month post partum our results suggest a slight increase in protein content (from 2.5 to 3.2%) and a decrease of lactose concentration (from 3.2 to 2.0%). Protein composition (SDS PAGE) and phospholipid pattern (TLC) remained unaltered within this early observation period. However, evident changes of the nutrient composition were observed in the milk of the late lactation. Protein levels in samples taken after 4.5 years were enhanced (4.98% ± 0.18) and the ratio of caseins and whey proteins was shifted to the latter. In contrast the lactose concentration was significantly lower (0.24% ± 0.09). The values obtained for the fat content were inconsistent in the samples of early (from 8.9 to 12.9%) and late (from 3.9 to 10.7%) lactation. This might be due to difficulties in milk sampling.

Since our results suggest obvious variations in the contents of at least proteins and lactose in the course of lactation, we are very interested to find out when these changes take place, whether this process is creeping or spontaneous, and whether it is accompanied by a physiological development/event. In addition we intend to get a closer look at the milk of the first two month post partum, including colostrum. Thus, our further analysis may be helpful for adjusting a formula to the requirements at different stages of lactation.

An accurate fatty acid content is regarded to be important to prevent chronic diarrhea. The unusual fatty acid composition - demonstrated for one time of lactation - may be more difficult to standardise for a milk replacer. According to this, one of our objectives is to perform a detailed analysis of the fatty acid pattern and its composition during lactation. To get more sophisticated knowledge on milk constituents we plan to extent our investigations on a larger amount of samples. Therefore we would like to increase the number of collaborating zoos. A long-term aim will be the examination of minor milk components e.g. vitamins, minerals, and hormones.

Author’s address:
S. Kölbl
Department of Biomedical Analysis
Institute for Medical Physics and Biophysics
University of MÒnster
Robert Koch-Str. 31
48149 MÒnster

Do captive plains zebra (E. burchelli) have a preference for individual grass species?

S. Armstrong1, N. Marples2

1Sparsholt College, Sparsholt, Winchester, Hampshire, 2Trinity College, Dublin, Ireland.

Most herbivores have been found to be selective in their plant choices whilst grazing. The aim of this project was to give recommendations regarding the ‘ideal’ grass mix for paddocks used to house captive zebra. In order to do this it was necessary to perform a series of taste tests to determine whether the zebra have a preference for individual species of grass. This study also looked at whether specific nutrients had an influence on the preferences shown for individual grass species or whether other factors such as physical form had an effect.
The research took place at Dublin Zoo, Ireland, where the herd consisted of six zebra; one castrated
adult male, 4 adult females and one juvenile female. Seven commercially available agricultural
temperate grasses were grown in plots 1m2 (Table 1). Once the grass had grown above normal
grazing height (4 cm) the plots were cut and fed to the zebra on consecutive days. The reactions of
the zebra to the grass was assessed and placed in an order of preference based on this assessment.
Four tropical species were also assessed, with cuts taken from ornamental plantings around the zoo
grounds (Table 1).
It was found that the zebra did in fact have a preference for individual grass species. The zebra
consumed all the grasses offered to them and once the preference had been determined it was tested
for correlation with nutrient content using Spearman’s Rank correlation tests. It was found that there
was a correlation between preference and Acid Detergent Fibre (ADF) (rs = -0.755, N = 11, p < 0.01)
and with total ash (rs = -0.636, N = 11, p <0.05).
Since it is unlikely that the tropical grasses would be used for planting in the paddock, the correlation
tests were repeat for the seven agricultural species. The only correlation found was between
preference and oil content (rs = -0.857, N = 7, p < 0.05). Further analysis found that preference also
appeared to be related to the morphology of the plant with the zebra showing a preference for stalkier
varieties compared to finer mat forming species. Comparisons of the nutrient content of the preferred
species with that of the common species of the African savannah, this found that the preferred species
of grass was also the closest in nutrient content to the savannah grasses. As a result it was possible to
make recommendations regarding the ‘ideal’ grass mix for paddocks housing captive plains zebra.

Author’s address:
Sparsholt College, Sparsholt,
Winchester, Hampshire
United Kingdom

Glucosamine and Chondrotin in the treatment of elephant and ungulate’s Osteoarthritis

C.W. Yang, A.S. Li, J. C. Guo

Taipei Zoo, Taiwan

Because of their heavy weight and the damage of articular cartilage in the older elephants, the animals often suffer from osteoarthritis. The symptom of osteoarthritis is arthrosis tumefaction. Animals become pain ridden, difficult to move, and have leg catatoria. Unusual movements often result in bone fracture and death. Glucosamine and chondroitin sulfate are substances found naturally in the body. Glucosamine is a form of mucopolysaccharide that is believed to play an important role in cartilage formation and repair. Chondroitin sulfate is part of complex protein molecule (proteoglycan) that gives cartilage elasticity.
From 1986 to 2002, Taipei zoo raised three female African elephants and one male African elephant. The animals had many records of difficulty in movements and of leg catatoria. One female was diagnosed with serious osteoarthritis in 2001 and subsequently died from complications related with a broken leg in 2002. Also an old Asian elephant with osteoarthritis died in 2002. Therefore, the elephants were excellent candidates for the medicinal use of glucosamine and chondrotin for cartilage maintenance. In 2002 we initiated the treatment of elephants with the addition of glucosamine (20mg/kg body mass for treatment, 10mg/kg body mass for health maintenance) and chondrotin sulfate in the elephant pellets, and also untied their chains at night and provided hot water to massage their legs. The animals showed no symptoms of osteoarthritis after the treatment. We have also treated other ungulates, such as a dromedary camel and horses, on a similar way..

Author’s address:
C.W. Yang
Taipei Zoo

Poster: Faeces consistency in captive tapirs

S. Lang1, E.P. Medici2 J. Fritz1, J.-M. Hatt3 J. Hummel1,4, M. Clauss1

1Institute of Physiology, Physiological Chemistry and Animal Nutrition, Munich, Germany, 2IPÊ - Institute for Ecological Research, São Paulo, Brazil, 3Department of Zoo Animals and Exotic Pets, Zurich, Switzerland, 4Zoological Garden of Cologne, Germany

The consistency of the faeces is one of the few medical parameters that is monitored in every zoo as a daily routine. Changes in faecal consistency are an early sign of digestive upset, and are often the first observation reported by animal keepers to the veterinary staff as an indication of a potential medical problem.
In captive tapirs, the assessment of faecal consistency is often prevented by the fact that these animals prefer to defecate in a water basin, which they have at their disposal in many facilities. However, we also experienced that the conception of “normal” tapir faeces differs widely between facilities. Therefore, we photographed tapir faeces from several facilities and from free-ranging lowland tapirs. Additionally, the particle size distribution in tapir faeces from captivity and from the wild was investigated by wet sieving.
With one exception, captive tapirs generally had faeces of a cow pie-consistency, with little indication of formed pieces. In contrast, faeces of free-ranging tapirs consisted of small, compact, formed balls. Only the faeces of one captive tapir, fed a very high proportion of roughage, resembled those of the free-ranging animals. These observations alone indicate that a higher proportion of concentrate (non-roughage) feeds in captive tapirs leads to softer, less formed faeces. Therefore, one would expect smaller faecal particles in captive tapirs as a reflection of the lesser proportion of roughage in their diets. In contrast, faecal particle size was generally higher in captive tapirs.
The results suggest that on the one hand, captive tapirs make little use of offered roughage (grass or lucerne hay), with the result of soft faeces. However, the roughage portion that they do ingest is masticated into larger particles than the forage they ingest in the wild. This could be an indication that the dentition of tapirs, which is different from that of other perissodactyla, is poorly suited for the mastication of hay forages and might therefore be the reason for the low acceptance of these forages observed in captive animals.

Author’s address:
Stefanie Lang & Marcus Clauss
Institute of Animal Physiology, Physiological Chemistry and Animal Nutrition
Schönleutnerstr. 8
85764 Oberschleissheim

Poster: The effect of different nutritional regimes on the ratio of essential fatty acids in juvenile lined seahorses, (Hippocampus erectus), 28 days after birth.

T. Oudegeest ¹, M. Laterveer ¹, J. Nijboer ¹, R. Hovenier 2, A. Beynen 2

¹Rotterdam Zoo, The Netherlands, 2Faculty of Veterinary Medicine, Utrecht University, The Netherlands

Essential fatty acids play an important role in the lives of many different animals. They are crucial in maintaining and improving nerve impulse transmission, appropriate immune responses and cell membrane fluidity. In juvenile fish, fatty acids are necessary in realising a normal development, specifically with regard to the visual system and intestinal system. As the pressure on wild populations of seahorses increases, public aquariums will become more involved with the captive breeding and the long term husbandry of this threatened species. To increase longevity and fecundity of seahorses it is important to improve culturing techniques and therefore increase knowledge on nutritional requirements.
In this study the nutritional value of two different feeding strategies has been assessed by analysing the uptake and ratio of essential fatty acids in juvenile seahorses. One group of juvenile lined seahorses was fed Artemia nauplii with nutritional enrichment
(DHA Selco) from birth till 28 days of age and one group was fed non-enriched Artemia nauplii (i.e. without nutritional enrichment) from birth till 28 days of age. After 28 days a fatty acid analysis was performed on both groups of seahorses as well as on the enriched and non-enriched Artemia. The same experiment was conducted with two groups of juvenile lined seahorses from birth till 14 days of age.
Preliminary results from a pilot study demonstrate a positive correlation between age and unsaturated fatty acids, particularly EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid), both required specifically by marine species.

Author’s address:
T. Oudegeest
Rotterdam Zoo, The Oceanium
Postbus 532
3000 AM Rotterdam
The Netherlands

Poster: Food consumption and weight development in captive Malayan sun bears (Helarctos malayanus) – preliminary results

S.T. Hoffmann ¹,², L. Kolter ¹, J. Pallauf ²

1AG Zoologischer Garten Köln, Germany, 2Justus-Liebig-Universitìt Giessen, Germany

The diet of wild Malayan sun bears consists mainly of insects and fruits high in fibre content. Mast periods with high abundance of energy rich easily digestible fruits are brief and unpredictable. It can be assumed that these features shaped the feeding and nutrition strategy of the species towards maximising energy intake at any time. This is consistent with the fact that sun bears in captivity do not display endogenously controlled seasonal cycles of feeding and fasting like other ursid species. Captive sun bears tend to be permanently obese. This is most likely a result of the lower activity performed by captive individuals and the difference in nutritional composition of zoo diets. The main source of energy for wild sun bears are tropical fruits, which contain a much higher amount of fibre and less soluble carbohydrates than the domestic fruits regularly fed in zoos. The body mass of wild bears varies between 27-65 kg, whereas captive animals range from 50 to 123 kg in bodyweight with the majority above 65 kg. The data are in general taken opportunistically without reference to food composition and consumption. This presentation deals with the effect of food and nutrient intake on the body mass of sun bears.
In the course of a study on digestive strategies with respect to fibre content, the food consumption was measured in four adult female sun bears at Cologne Zoo. The intake of main meals was recorded by weighing the offered food and the leftovers individually. The intake of scatter feed items was estimated for each individual. The animals were weighed regularly over a period of ten months, during which the fibre content of the diet was varied systematically. The data include a four weeks “mast period” mimicking the natural situation with respect to sugar and fibre content of the diet.
The weight development varied individually, which indicates different maintenance requirements. In the running study on the effect of crude fibre on digestion parameters, food consumption, and nutrient intake, the results will be discussed with respect to energy intake, individual activity levels and feeding habits. The findings highlight the relevance of individual demands of captive animals, which have to be considered with respect to body mass maintenance and health care.