Applications 6-10

FEEDING FUSSY FOLIVORES: NUTRITION OF GENTLE LEMURS

Anna T.C. Feistner PhD1 and Thomas Mutschler1,2
1 Research Department, Jersey Wildlife Preservation Trust, Les Augres Manor, Trinity, JE3 5BP Jersey, Channel Islands, United Kingdom, 2 Anthropology Institute, University of Zürich, 8057 Zurich, Swizterland

The genus Hapalemur comprises five currently recognised taxa, three of which are critically endangered. They range in size from 700-2300 g, but most weigh less than 1500 g. All members of this genus are specialist feeders on the monocot family Poaceae. The forest lemurs Hapalemur g. griseus, H. g. occidentalis, H. aureus and H. simus all spend >85% of their feeding time on bamboos, whereas the marsh dwelle r H.g. alaotrensis spends >95% of feeding time on papyrus, reeds and surface grasses. All are highly selective, choosing shoots, leaf bases, growing tips and pith. These lemurs can thus be classed as highly selective and almost exclusively folivorous. All the Hapalemur species are represented in captivity, although most (cf. H. g. alaotrensis) only in small numbers. However, folivores are generally difficult to maintain in captivity, because plant material is extremely variable in its nutritional composition, and regular quantities of appropriate forage may be difficult to obtain. Studies of nutrition in both wild and captive Hapalemur indicate that these lemurs have a typically folivorous diet containing high protein and fibre and relatively low energy. It is unclear how these small lemurs can sustain themselves on a completely folivorous diet. Constraints of low energy and low fibre digestibility could theoretically be met by: reduction in BMR, specialisations of the digestive tract, and behavioural adaptation. The existence of these strategies in Hapalemur is reviewed and recent work from field studies on H. g. alaotrensis suggests several implications for captive management: e. g., the diet should be high in fibre to maintain gut function; pelleted diet should be leaf-eater/folivore rather than a primate pellet; large amounts of forage should be provided to allow the lemurs to be selective; and sufficient quantities of fibrous food should be given to allow for night time feeding.

FEEDING BEHAVIOUR IN TWO GROUPS OF BLACK-AND-WHITE RUFFED LEMURS (Varecia v. variegata, KERR 1792)

Christoph Schwitzer1 and Werner Kaumanns Dr.2
1 University of Cologne, c/o Zoologischer Garten Köln, Riehler Str. 173, 50735 Köln, Germany,2 Dr. Werner Kaumanns, Deutsches Primatenzentrum, AG Haltungsbiologie, Kellnerweg 4, 37077 Göttingen, Germany

Obesity is supposed to be a problem in many captive Black-and-white Ruffed lemur colonies. Furthermore, an increase in the number of infants per litter in captive females is reported. Both phenomena are assumed to be nutrition-related. This study intends to investigate the feeding behaviour of captive Black-and-white Ruffed lemurs in order to provide basic data, which can be used in further studies on obesity. The feeding behaviour as well as the amount and composition of food consumed by 12 Black-and white Ruffed lemurs kept in two groups of six animals each at the Cologne Zoo was examined no experimentally over a period of four months. Interactive behaviour was recorded additionally during feeding and non-feeding sessions. Data refer to a total of 220 hours of focal animal sampling. For nutritional analysis, the computer program „The Animal Nutritionist“ (Version 2.5; N-Squared Inc. & Durango Software) was used. The results were compared to recommendations, provided by the program as for old-world monkeys and to values from a study by Ganzhorn (1988). The latter refer to nutritional analyses of plants consumed by free-ranging Brown lemurs (Eulemur fulvus) and other lemur species, which share their habitat with Ruffed lemurs. In a second, „pilot“-part of the study, the transit times through the gastrointestinal tract for eight different feedstuffs were measured once each in three Black-and-white Ruffed lemurs. In addition, commercial applemash, enriched with sucrose (358 % of the original concentration) as well as non-enriched, was offered to two Ruffed lemurs in order to assess preferences. Data analysis is ongoing. Preliminary results show that the animals consumed a diet that was 50 % to 64 % higher in energy-concentration (Kcal / g DM) than recommended by „The Animal Nutritionist“. With reference to the major constituents, the concentration of crude protein (% DM) in the diets for the two different lemur-groups varied from a low of 39 % to 86 % of the recommendations. Recommended values for fat, carbohydrate and crude fiber were not available. Referring to vitamins, ascorbate (vitamin C) seems to be highly overdosed (642 % - 774 %). Transit times for the eight feedstuffs tested ranged from 70 min. (apple) to 283 min. (pear). The transit times seem to be higher than those found by Overdorff (1988) for Eulemur rubriventer, but seem to be much lower (as seems to be characteristic for small frugivores) than those of the folivorous Hapalemur species (Santini, 1992) and of the South American Alouatta species (Milton, 1981). A preference for fruits in general and for feedstuffs with high sucrose-concentration was evident. The preliminary results of this study are compatible with the assumption that obesity problems in captive Ruffed lemurs might be nutrition-related.

DIET COMPOSITION AND DIGESTIBILITY IN CAPTIVE BLACK AND WHITE RUFFED LEMURS (Varecia variegata variegata)

S. Lovric 1, Joeke Nijboer BsC2, and Anton.C. Beynen Prof.Dr.1
1 Department of Nutrition, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands,2 Blijdorp Zoo, Rotterdam, The Netherlands

The composition of the food consumed by two black and white ruffed lemurs in Blijdorp Zoo (Rotterdam, The Netherlands) was studied. The macronutrient and mineral composition of the diet consumed was chemically analysed. The composition was compared with that of diets used in other zoos. The apparent digestibility coefficients of crude protein, carbohydrates, fat and fiber were found to be low. The observed digestibilities will be discussed in the light of the persistent diarrhoea in the lemurs.

DIET COMPOSITION AND DIGESTIBILITY IN CAPTIVE EMPEROR TAMARINS (Saguinus imperator subgrisescens)

M.I. Bieleveld1, Peter Klaver Dr.2, J. Govers2, and AntonC. Beynen Prof. Dr.1
1 Department of Nutrition, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands,2 Artis Zoo,Postbus 20164, 1000 HD Amsterdam, The Netherlands

The composition of food consumed by two emperor tamarins in Artis Zoo (Amsterdam, The Netherlands) was studied. The macronutrient composition was chemically analysed and the micronutrient composition was calculated on the basis of product information and food tables. The composition was compared with the nutrient requirements and a commercial diet for New-World monkeys. The diet consumed contained 14.9% protein when expressed for a dry matter content of 90%. The levels of vitamins A and D3 in the food consumed were very high and the calcium concentration was low. The apparent digestibility coefficients for the macronutrients were found to be high. The diet contained almost no lignin and the apparent digestibility of the crude fiber fraction was as high as 60%.

EFFECTS OF WHEAT IN CALLITRICHID DIET

Mauvis A. Gore PhD1,2, Manfred Brack Dr.2, Florian Brandes2, Thomas Motthes3, Ramona Lenzner 2, and Franz-Joseph Kaup 2
1 Royal Zoological Society of Scotland, Edinburgh, Scotland, United Kingdom, 2 German Primate Centre, Göttingen, Germany, 3 Leipzig University, Leipzig, Germany

Captive callitrichids are prone to developing intestinal problems. Captive and natural callitrichid diets differ enormously and diet has been suggested to play a major role in Wasting Marmoset Syndrome. Proteins in wheat, soy and milk are included in callitrichid diets of most colonies given in the literature. These proteins, however, have been suggested to cause an immune reaction in Saguinus oedipus and Callithrix jacchus. A similar finding relates to coeliac disease in humans. To investigate this observation under controlled conditions, wheat was chosen as a test protein. Twenty-three males and females of the two species were included in the study. All animals were fed the same diet, with the exception that one group had wheat and the other had rice in their diet. The two groups were balanced for species and sex. Soy and milk products were excluded from both diets. Health checks were made continuously throughout the 6-month pilot project. Blood samples and microscopic biopsies from the colon were taken at the beginning, at 3 and at 6-month intervals. Both diets were readily ingested and health status was maintained throughout the study. Results showed changes in the colon and an immune reaction to gliadin, a wheat protein. A further immune reaction was also observed. The results suggest that the diet of captive callitrichids must be reconsidered.