Course no; VMD-512 Zoo/wild animal breeding, nutrition, management and health care NUTRITION SIGNIFICANCE OF FEEDING WILD ANIMALS 1. 2.
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Feeding wild animals is different under captive conditions and in free ranging conditions. It is a controlled activity in case of captive wild animal species unlike free ranging wherein, the animal by itself attempt to have some control measures. Differing feed habits are seen in captive wild animal places due to multiple species, hence, preliminary knowledge of the feeding related activities in the concerned wild animal species and a basic knowledge of nutrition, proper diets etc. is required. Scientific feeding-strategies will be the basis for scientific management of wild animal places. The criteria for evaluating the suitability of a diet for a given wild species are growth, reproductive success, and longevity. Present established nutrient requirements for domestic animals can be used as only guidelines as they promote rapid and efficient gain and high milk yield or egg production unlike the goals defined for wild animals in captivity. Nutrient concentrations, types and amount of foodstuffs, methods of presentation, and feeding frequencies should be based on the physical and behavioral attributes of the species.
CLASSIFICATION OF WILD ANIMALS BASED ON FEEDING BEHAVIOR Herbivores They constitute the wide spectrum of different species of wild animals with anatomical adaptations comprising of symbiotic microbial population of bacteria, protozoa etc. The feed resources to these animals have low nutritional values and are bulky in nature. Among herbivores, the ones with complex stomach (ruminants) are the most efficient ones and the roughages and forages are most efficiently utilized by the species. Microbial fermentation is the mode of digestion in these species. Example: Gaur, deer, giraffe, antelopes like blackbuck, buffaloe etc. Also pregastric fermenters like kangaroo, wild pigs, hippopotamus etc. and hind gut fermenters like rabbits, guinea pigs (cecal fermentation) and zebra and wild asses (colon fermentation) are seen under captive conditions. General guidelines for feeding herbivores 1. The basic diet of most ungulates and other herbivores should contain roughage and concentrate pellet /mash. The mash/pellet should be formulated to complement hay/roughage. 1
2. Free water should be provided at all times 3. Hay roughage quality should be carefully evaluated 4. Nutrient level should reflect the need of the age, sex or species group with highest estimated requirement. 5. Special attention should be paid to level of protein, fibre, vitamin E, calcium, phosphorus, copper and selenium, since the target level and actual content in the feed may vary. 6. Deficiencies should not be addressed by top dressed supplementation, as they can rarely be delivered with any accuracy. 7. When top feed/ browse are used as behavioral stimulation, care must be taken to limit amount and type in view of the potential for toxicity. Some herbivores like colobine monkey and red panda require specialized diet. The development of high fibre formulated product (such as extrude biscuits) will help over traditional zoo diet. CARNIVORES Carnivores are the meat eating animals and require highly digestible and high quality food resources with nearly all the types of nutrients. The various species of this group require most of the times unique type of nutrition. For example, felids need a dietary requirement for amino acid ‘taurine’ and preformed vitamin A and essential fatty acid ‘arachidonic acid’. General guidelines for feeding of carnivores 1. Commercial canned, frozen or dried diet formulated for domestic dogs and cats can provide a basis for the diet of many carnivorous and insectivorous zoo mammals. 2. Prey items such as rats, mice, chick, fish or invertebrate can be given on a regular basis; also as whole prey is expensive compared with prepared foods, such items can be restricted to ≤30% of the diet dry matter. 3. Effective diet should provide some stimulation to teeth and gum to prevent gingivitis and oral abscesses. 4. The use of long bones with meat attached is recommended for prevention of metabolic bone diseases. 5. Rodent prey or small rib bones may be offered once or twice per week to small carnivores. 6. Insects have low calcium content; hence supplementation with calcium is essential. 7. When fish is being fed significantly in the ration, thiamin and vitamin E supplementation is given in controlled amount based on documented daily feed consumption. 8. All personnel involved in handling, preparing and distributing meat and fish should follow sanitary methods of food handling. Food items should be dated on arrival and should be used within prescribed time. OMNIVORES
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Large group of wild animals belong to this in general. Most of the rodents, flying fox, sloth, bears, non-human primates, pigs many species of birds etc. belong to this group. Carbohydrates become the major nutrient received from the plants, while moderate amount of protein and fat are received from meat sources.
General guidelines for omnivores 1. Omnivores of primates and other mammals select food item from a broad array of plant and animal food in the wild but it is not necessary that they must be offered a similar array of food in captivity 2. Due to the wide differences in composition between plants eaten in the wild, it is difficult to replicate in the natural diet a practical approach would be to provide a diet that will meet estimated nutrient requirement while also providing sufficient fiber for normal digestive function and sufficient diversity to provide behavioral stimulation. SIGNIFICANCE OF BALANCED NUTRITION Longer life span of the animal Maximal reproduction Maximal infant survival rate Appreciable health status Acquiring of good immune mechanisms GENERAL NUTRIENTS AND FEED STUFF Carbohydrates This is the chief source of energy in case of wild animals. Ruminants like deer or giraffe or antelope make use of the complex carbohydrates subsequent to the bacterial actions in the rumen and the rumen micro flora help the proper digestion of nutrients. Cereals, grains, roots, tubers and fruits have high carbohydrates. Fruits are rich in pentoses and hexoses, whereas the tubers and seeds are rich in glucose. PROTEINS Provision of adequate amounts of protein to wild animals especially to the carnivores is vital. The proteins comprise the ingredients of internal frame work of cells esp. the interstitial cells like dentine, osteoid tissue, connective tissue etc. Essential amino acids like Arginine, methionine, Threonine, leucine, lysine etc. are to be given importance during the provision of protein rich diets. Protein deficiency may result in retardation of the growth rate, cessation of lactation in case of nursing animals, impairment of reproduction, decreased body resistance level etc.
FATS Fats provide the fat soluble vitamins like A, D, E and K. 3
In addition, they provide satiety value in addition to giving palatability to the feed. Provision of optimal amounts of fat is a must for the wild animal species. Provides concentrated form of stored energy and fat reserves for the provision of energy during the adverse climatic extremes. Eg., elephant seal spends considerable time on land without any access to food while suckling the pups. In such occasions, fat is the major nutrient factor that helps the survival of the concerned species. Similarly, in case of hibernating animals like bears in cool regions it is the fat that gets accumulated often and is useful as an energy resource in winter months. ROUGHAGES Tree and shrub leaves, grass and legume silages, straw, fodder, hulls, shells, maize, hay etc. form the roughages. They are bulky in nature but are poor in energy content and are rich in fiber. CONCENTRATES These are low in fiber but are rich in protein or energy content. Cereal grains, non-cereal seeds like amaranthus green, grain milling by-products like wheat and rice bran, beet pulp, citrus pulp, molasses etc. fall under this category. Fish meal, dried milk products like skin milk powder, sunflower meal, cotton seed meal etc. provide more than twenty per cent crude protein. MINERAL MIXTURES Mineral supplements need to be added to the dietary items. Among minerals, it is the zinc that has effect on the hair growth. Calcium with phosphorous are also to be given maximum significance in case of wild animals. Deficiency of minerals like calcium and phosphorus may lead to development of bone disorders like rickets, osteodystrophy etc. Nursing animals need an additional allowance of calcium in their dietary items. VITAMIN SUPPLEMENTS Vitamins like fat soluble ones and water soluble ones are of much helpful in various metabolic functions occurring in the body. Care has to be paid in the provision of adequate amounts of vitamins to the diet of captive wild animals. The vitamins can be supplied along with the main diet as a special mixture to rectify feather loss like conditions. Species like red vented bulbul, bats, guinea pigs, non-human primates etc. are in need of direct supply of vitamin C because they lack the enzyme L-gluconolactone oxidase required for the synthesis of vitamin C. 4
WATER Watering in case of wild animals has to be given more significance. Generally wild animals prefer water content and even in the wild, wild animals move to the water holes frequently in every day. However, certain species may not take water much like blackbucks. The water requirement may be met by water content of food itself or through the oxidation of organic constituents that produces metabolic water. High moisture diets are generally preferred by the wild animals like non-human primates. Wild ruminants drink water either in the late evening or early morning. Camels have capacity to take more water at a time. Wild animals like felids require the provision of water ad libitum. FEEDING OF NEO NATAL CALF
Identify the signs of hungry status Frequent making of sound When hungry, the calf attempts to suckle the tip of the finger kept near the mouth. When stomach is full, the calf tends to go for sleep with snoring sounds that are well audible. Mode of feeding Large sized enema or a big-sized bottle like container with tube may be used and approximately 10% of the body weight may be taken as a rough estimate of feed requirement. Regular calf nipples attached to bottles of adequate volume or buckets can be used for the orphaned elephant calf. Elephant calf may be taught to drink on own. This may require a tub with milk. Dip the trunk in the milk of tub and it may thus get accustomed to suck the milk through the trunk and place it in mouth. Time of feeding Increase the frequencies of feeding in case of calf unlike the adult elephant and in the beginning feeding is to be done in day and night. When the calf reaches 2 or 3 months of age, night feedings may be gradually stopped. When the calf is 9 months old, 4 feedings is enough per day. Amount of feeding The elephant calf consumes 1.5 to 2 liters of diluted milk at a time in one to two hours and 12 to 16 liters may be needed in a day, in general. Try to leave them little hungry. Over feeding is harmful than slight under feeding of calf Types of Feed Protective immuno-globulins are given soon after the birth and inorder to establish the calf’s immune status. 5
Older calves are given immuno-globulins by subcutaneous administration as they are not well absorbed via oral route. The volume of the colostrum consumed by a newborn elephant during the first 24 to 48 hours of life is approximately 2 to 10 liters Tender coconut water may be given frequently to quench the thirst Coconut oil is the nearest artificial replacer to the fat of the elephant’s milk COMPOSITION OF MILK OF ELEPHANT
Milk
Protein(%)
Fat(%)
Carbohydrate(%)
Solids(%)
Fiber (%)
Elephant’s milk
19.9
0.63-6.2
4.0-8.36
8.27-17.3
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Artificial feed formulas Introduce in a gradual manner. Monitor for signs of indigestion if any. ITEM
Protein (%) 1.7
Fat (%)
Carbohydra te(%) 8.0
Solids(%)
Fiber(%)
Rice-based 1.5 12.4 0.04 formula for elephant calf Elephant calf under artificial feed formula should always gain a minimum of 0.5 kg body weight per day (recordings are available even with a weight gain of about 1.5 kg per day for extended periods of time). Weigh t
Energy requirement per day
Rice based formula required per day
100 kg
6000-8000 kcal
400-550 oz
200 kg
16,000-20,000 kcal
1100-1333 oz
Artificial feed- formula intolerance Monitor the signs of ill health on introduction of the new artificial feed formula Rule out pathogen or intolerance of artificial feeding formula If intolerance is suspected due to the formula, discontinue the artificial feed formula If above formula is discontinued, feed water or 5 to 10 per cent dextrose until the elimination of the most of the old feed formula and subsequent introduction of a new artificial feed formula.
Nutrition in Wild Birds Avian diets for many species are extrapolated from the Nutrient Requirements of Poultry published by the NRC. Nutrition in Psittacines 6
1. The pet bird population consists largely of psittacine species, primarily passerines and other genera such as toucans. 2. Psittacines eat plant-based diet and can be classified overall as florivores. 3. The diet includes fruit, nectar, seeds, or a combination—varies by species. 4. Some species ingest insects or carrion. 5. Grit, while necessary for some passerines and columbiformes, it is not needed by psittacines. 6. If seeds are consumed by psittacines, they are hulled before ingestion. 7. Strictly seed diets, regardless of supplementation, are suboptimal for psittacine species. Deficiencies of vitamin A, protein (the amino acids lysine and methionine in particular), calcium, and other nutrients occur in most psittacine species on seed-based diets. Protein 1. The amino acid deficiencies noted in psittacine birds on seed-based and table-food diets are lysine and methionine. 2. Increased fiber in diet causes increased fecal protein “loss.” 3. Birds on low-fiber, and readily digestible diets (such as nectarfeeding lories and lorikeets) do well on diets with digestible protein levels as low as 3–5%. 4. Adult maintenance levels of protein for budgerigars and cockatiels is (7–12%) and for African Grey parrots (10–15%). 5. Protein requirements for growth and for egg-laying hens are higher than maintenance levels in all birds. 6. Periods of heavy molt increase protein requirements, particularly sulfur-containing amino acid cysteine. 7. Excessively high dietary protein cause renal insufficiency and gout in birds with pre-existing renal impairment or a genetic predisposition to gout. 8. Cockatiels with no pre-existing renal disease can tolerate extremely high dietary protein levels (up to 70%) with no renal impairment. 9. Sudden increases in dietary protein overload the kidneys, producing hyperuricemia and visceral gout. 1. 2. 3. 4.
Fat Dietary fat provides essential fatty acids, energy, and hormone precursors. It contributes to egg yolk formation and aids in absorption of fatsoluble vitamins. Excess leads to obesity, metabolic diseases, cardiac disease, and atherosclerosis. Psittacines requirement of fat for reproduction is lower than those in poultry, because the psittacines' altricial (naked and blind and dependent on parents for food) young do not require the same quantity of fatty acids as do the precocial (of hatchlings; covered with down and having eyes open; capable of leaving the nest within a few days) young of chickens. 7
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Vitamins Vitamin A and Carotenoids Vitamin A necessary for vision, reproduction, immunologic integrity, and growth and for maintenance of epithelial cells in respiratory, GI, and renal tissues. Deficiency is noted in psittacines on all-seed diets. Diets containing levels of vitamin A in excess of 10,000 U/kg of feed (has shown to be toxic in cockatiels). High levels of vitamin A in lory (Small brightly colored Australasian parrots having a brush-tipped tongue for feeding on nectar and soft fruits ) and lorikeet (Any of various small lories) have been linked to vitamin E deficiency, decreased fertility, and an increased incidence of iron storage disease. Carotenoids in birds are precursors for the body's formation of vitamin A and also act as antioxidants and are necessary in some species (such as canaries and flamingos) for feather pigmentation.
Vitamin D 1. The primary function of vitamin D is to increase absorption of calcium and phosphorus. Vitamin D can be obtained either directly from the diet or from UV light exposure. Vitamin D is not a naturally occurring dietary element for birds—their natural source of vitamin D is sunlight. 2. In the absence of natural sunlight, the minimum oral vitamin D requirement for African Greys is comparable to commercially raised poultry (200 IU/kg) 3. Some UV light is critical in this species for optimal activation of vitamin D3. 4. African Greys require consistent UV exposure to maintain adequate vitamin D3 and, therefore, calcium levels. 5. Pet birds are to be exposed to direct sunlight (with appropriate caution regarding excessive heat) or use UV bulbs. 6. Toxicity is caused by excessive supplementation. Some psittacine species like macaws, are sensitive to excessive dietary vitamin D, and develop soft-tissue calcification and renal failure. 7. Toxic levels for psittacines have not been established, but levels that may be toxic for poultry begin at 2,800 IU/kg of feed. 1. 2. 3. 4.
Vitamin E Clinical signs of vitamin E deficiency include weakness and inability to stand or hold wings in normal posture. Severe generalized myopathy with muscle atrophy, degeneration and necrosis, and replacement with fibrous connective tissue can occur with chronic pronounced vitamin E deficiency. Prior supplementation with 25–100 IU vitamin E/kg has been proposed before feeding the diet. Over supplementation (500–10,500 IU vitamin E/kg food) may result in decreased growth and coagulation disorders, possibly from creating vitamin K deficiency rather than directly from vitamin E toxicity. 8
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Nutrition in Passerines The order Passeriformes contains >5,000 species of birds and includes frugivorous, carnivorous, insectivorous, and granivorous species. Most passerines maintained as pets (finches and canaries) fed primarily seed and are considered florivorous to granivorous. Commercial seed mixtures for canaries often contain a mixture of canary, rape, niger, hemp, linseed, and oats. Most of these commercially available seed mixtures are deficient in numerous vitamins and amino acids. The fat soluble vitamins A, D 3, E, and K are generally low, the calcium:phosphorus ratio is poor, and the amino acids lysine and methionine are insufficient. Egg food (hard-boiled egg based soft food with added vitamins and minerals) is fed by the breeders during the reproductive season, with soaked seed added to increase acceptance. Organic pellets or pellet-based mash, which contains balanced nutrients, are offered by many breeders as a nutritional alternative. Soluble grit (ie, oyster shell, cuttlebone) should be provided to canaries and finches. Sprouts, fruits, and vegetables are psychologically stimulating and enhance breeding in these passerines. Plumage colors in canaries partially depend on the pigments in the diet. For example, red-colored canaries are fed canthaxanthins before breeding season. Carotenoids vary in their bioavailability, and there are species differences in the types of carotenoids that are absorbed and metabolized.
Nutrition in Gallinaceous Birds 1. Many gallinaceous birds are omnivorous. 2. Commercial diets for domestic fowl, domestic turkeys, and Japanese quail are available. 3. During nonbreeding periods, a maintenance diet containing <20% CP can be offered 2–3 times daily. 4. During breeding season, food should be offered free choice and contain a higher protein content (20–25% crude protein). 5. Most quail are primarily seed-eaters and are easy to feed. 6. Monensin is toxic for guinea fowl. All gallinaceous birds should have access to grit. 7. Poultry pellets generally contain adequate calcium and vitamins, and additional supplementation should be done only when a deficiency exists. Nutrition in Columbiformes 1. Most pigeons are either granivorous or frugivorous, with some invertebrates also consumed. 2. Columbiform parents feed their young with crop milk, produced from desquamated epithelial cells and glandular secretions of the crop. 3. Crop milk is rich in fat and protein and nearly devoid of carbohydrates. 9
4. Seed-eating pigeons switch rapidly from crop milk production to feeding their young mostly regurgitated seed. 5. Frugivorous pigeon squabs (at least of the white-crowned pigeon, Columba leucocephala) rely on crop milk for a longer period, which increases the interval between clutches. 1. 2. 3. 4. 5. 6. 7. 8.
Nutrition in Raptors Most medium to large raptors consume whole vertebrate prey. Commonly feeds are mice, rats, young chickens, quail, and pigeons. Kestrels generally consume insects. Fish are natural diet of piscivorous raptors such as ospreys (Large harmless hawk found worldwide that feeds on fish and builds a bulky nest often occupied for years) and sea eagles. If fish or day-old chicks are fed, thiamine supplementation (30 mg/kg feed) twice weekly on an average is recommended. Small raptors can eat 20–25% of their body wt/day; larger raptor species consume considerably less (as little as 5%). Captive raptors should be weighed regularly, and food volume adjusted as indicated above. On organ meat-based diet, calcium supplementation at the rate of 10 g calcium carbonate/kg fresh meat should be added.
Nutrition in Piscivorous Birds 1. Penguins, pelicans and other fish-eating species in the wild feed primarily on fish, crustaceans, and squid. These food sources vary widely in their fatty acid, vitamin, and carbohydrate contents. 2. Most important aspect of feeding piscivorous birds is fish quality. 3. Diets should contain several fish species. Captive seabirds develop preferences for a particular fish if fed exclusively for prolonged periods, which lead to deficiencies. 4. Supplements added to captive penguins include salt, fatty acids, and vitamins A, D, and E which depend on the quality and content of the primary diet. 5. Dietary salt (NaCl; 0.5–1 g salt/bird/day) is often to be provided to birds in freshwater exhibits to help maintain proper functioning of the salt glands. 6. Supplemental essential fatty acids are recommended during reproduction and molting when smelt is the primary diet. Thiamine 1. Process of thawing the fish in running water depletes water-soluble vitamins in them in addition many fish have thiaminase, leading to thiamine (B1) deficiency. 2. Supplementation of thiamine is recommended at 25–30 mg/kg fish, daily or at least twice weekly. Vitamin E 1. Most fish are deficient in vitamin E. 2. Supplementation with 25–100 IU vitamin E/kg fish is recommended. Nutrition in Waterfowl 1. The order Anseriformes includes ducks, geese, and swans. 10
2. Waterfowl vary from strictly herbivorous (swans, most geese, most ducks) to highly piscivorous (marine ducks, mergansers). 3. Protein and multiple vitamin deficiencies lead to poor plumage, swollen joints, and pododermatitis. 4. Young waterfowl should be fed with higher fat and protein content diets. 5. Excessively rapid growth of large waterfowl must be avoided to prevent bone and joint deformities, such as angel wing and perosis. Nutrition in Ratites 1. Ratites are flightless birds and do not require the high-energy diets of flighted birds. 2. Ostriches, rheas and emus consume low-quality roughage in nature, which is fermented in their intestinal tract. 3. The nutritional requirements of juveniles are much higher in protein and calcium than those of adults. 4. Breeders have even higher calcium requirements 5. Ratite production for meat and leather requires specialized diet to maximize growth and minimize cost. Bringing an animal to market in minimal time is financially advantageous, but excessively rapid growth can lead to angular deformities of the legs. 6. Cassowaries are rainforest ratites and are primarily frugivorous. Adult birds consume about 3–5 kg of food/day. Diets fed in zoos include fruits and vegetables such as bananas, apples, tomatoes, papaya, watermelon, grapes, mangoes, plums, nectarines, cherries, kiwi fruit, figs, sweet potatoes, and carrots. These are supplemented with animal protein (eg, day-old chicks, mice, dry dog food). Nutritional Requirements for Ratite Production Estimated Crude Calcium Diet Age (mo) Body Fiber (%) Protein (%) (%) Weight (kg) Pre-starter 0–2 0.8–10.5 25 1.2–1.5 Starter 2–4 11–28 21.5 1.2–1.5 >4 Grower 4–6 29–52 17 1.2–1.5 >4 Finisher 6–10 53–90 13.5 0.9–1.0 Post-finisher 10–20 91–110 8.5 0.9–1.0 Maintenanc Mature 8.0 0.9–1.0 6 e Breeder Laying 14 2.0–2.5 8 Nutrition in Crocodilians 1. Captive alligators and crocodiles are usually fed a combination of rodents, poultry, fish, and meat-based diets. A varied diet is recommended. 2. Diets consisting primarily of fish should include ≥3 different species of fish and should be supplemented with 25–30 mg of thiamine and 100 IU vitamin E/kg of fish, as fed. 3. Signs of vitamin E deficiency (eg, steatitis) have been reported in crocodilians fed fish inadequately supplemented with vitamin E. 11
4. Alligators can digest some carbohydrate; however, the total carbohydrate in the diet should not exceed 20%. Nutrition in Snakes 1. Snakes feed almost exclusively on vertebrate or invertebrate prey. A few species are specialized egg feeders. 2. Most boids, pythons, vipers, colubrids, crotalids, and elapids are fed mouse pups, mice, chicks, hamsters, rats, guinea pigs, chickens, ducks, or rabbits. 3. Frozen, thawed preys are usually used in zoos. Prey should not be fed cold, thawing under refrigeration is recommended. After thawing, prey should be fed at room temperature, or preferably warmer. Some species (eg, king cobra, hognose snake, garter snake) feed primarily on other poikilotherms in the wild. Some of these species can be switched, at least in part, to homoeothermic prey, which are more available and less expensive. 4. Minced prey can be fed in agar, gel, or in sausage form. Advantages include the ability to formulate and feed a nutritionally complete diet, to add a balanced vitamin and mineral mixture, and, if needed, to add antibiotics or coccidiostats. 5. The scent of preferred foods can be rubbed on the new item. Alternatively, the preferred foods can be inserted into, or attached to, the new food. Anoles, yellow rat snakes, frogs, and smelt, depending on natural feeding habits, can be fed, when homeotherms are not accepted. 6. Prey size is usually proportional to snake size and should not be much larger in diameter than the snake's head. 7. Snakes that are routinely handled can be fed in a separate tank to reduce biting. 8. To reduce the chance of regurgitation, snakes should not be handled for 3 days after feeding. 9. Most species should be fed every 1–2 wk. Some large, less active snakes may typically go 6 wk between feedings. 10. Force-feeding should be used only if necessary. Animals can be force-fed whole prey lubricated with egg white by gently inserting the food a few inches down the throat using forceps. Tube feeding is also possible using ground (homogenized) prey. Nutrition in Turtles 1. Freshwater turtles in the wild eat primarily animal matter and some plant material. Some species may be carnivorous when young and shift to omnivorous or herbivorous feeding patterns as adults. 2. Most aquatic turtles cannot be considered as strict carnivores, because they consume at least some plant material. Commercially available turtle feeds are extruded or pelleted diets and are typically 30–50% protein. 3. Omnivorous species would benefit from the addition of some fruits or vegetables. Nutrition in Tortoises 1. Tortoises are herbivorous and must consume plant material to maintain healthy gut physiology. Microbial fermentation of plant fiber can be a significant source of nutrients for tortoises. 2. Diets of tortoises in the wild often contain >15% protein (dry-matter 12
basis) in plant materials consumed. 3. Small and large tortoises can be maintained on appropriately formulated, extruded, pelleted, or coarsely ground tortoise diets. 4. Larger tortoises, such as Aldabra or Galapagos tortoises, can consume alfalfa hay along with a complete pelleted food formulated for tortoises or exotic herbivores. Hay should be cut short as it is not possible for these tortoises to chew long hay due to mouth shape. 5. A vegetable mix consisting of broccoli, green beans, leafy greens (eg, romaine, green leaf lettuce, endive) kale, and shredded carrots may be fed as a supplement to a formulated tortoise diet. Such mixes contain adequate protein, calcium, and micro-nutrients; only limited vitamin and mineral supplements should be added. 6. Cultivated fruits are poor source of protein, calcium, and micronutrients; if fed in significant amounts, vitamins and minerals should be added apart from oyster shell and pea gravel as “mining” activity has been seen in free-ranging animals. 7. Shell deformities in tortoises may be the result of rapid growth associated with the consumption of high-protein diets or due to humidity and temperature. Nutrition in Lizards 1. The feeding patterns of lizards are extremely diverse. Lizards may be insectivorous (eg, day and leopard gecko, whiptail lizard, anole, chameleon), carnivorous (eg, varanids such as monitor lizard, Gila monster, Mexican beaded lizard), omnivorous (eg, many iguanid and agamid species), or herbivorous (eg, iguanid species, prehensile-tailed skink). 2. Insectivorous lizards in captivity are usually fed diets of mealworm larvae or crickets. Because calcium concentrations in these, and in most insects, are extremely low (0.03–0.3% calcium with 0.8–0.9% phosphorus), the inverse calcium: phosphorus ratio must be corrected before the insects are fed to lizards. A diet with a balanced vitamin and mineral mixture and containing 12% calcium as calcium carbonate can be fed to crickets or mealworm larvae 2 days before the insect is fed to the lizard. However, this diet should not be used to maintain a cricket colony. Within 2 days of feeding the high-calcium diet, the gut of the insect is filled with calcium, raising the calcium concentration of the insect to ~0.8–0.9% and resulting in calcium: phosphorus ratio of ~1.2:1. A satisfactory high-calcium diet for crickets can be inexpensively made by using 29% wheat middlings (Any commodity of intermediate quality or size (especially when coarse particles of ground wheat are mixed with bran), 10% corn meal, 40% ground dry cat or dog food, and 21% ground oyster shell or calcium carbonate. Larger insectivorous lizards may also consume mouse pups and earthworms. 3. Carnivorous lizards may be offered mouse or rat pups, adult mice and rats, chickens, and eggs. The size of prey should be appropriate for the lizard species. 4. Omnivorous lizards are usually fed a combination of foods including insects, vertebrate prey, and a chopped vegetable mixture. Most lizards should be fed daily (juveniles and small species) or at least every other day. Large carnivorous species should be fed 1–2 times/wk. 13
5. Herbivorous lizards are adapted to ferment plant fiber in enlarged hindguts. The microbes in the cecum and colon digest plant fiber that the lizard could not otherwise use. As with tortoises, herbivorous lizards should be fed plant-based diets to assure healthy gut function. The use of insects, vertebrate prey, or diets high in fruits is not advised, because these feeds are low in fiber and are inappropriate for herbivores. Diets for lizards may be commercial preparations formulated for herbivorous reptiles, or vegetable mixes.
Some recommended Nutrients and their concentrations for Reptiles Concentrationa Carnivorous Omnivorous Nutrientb Reptiles Reptiles c Crude protein 30–50% 20–25% Linoleic acidd 1.0% 1.0% Calcium 0.8–1.1% 1.0–1.5% Phosphorus 0.5–0.9% 0.6–0.9% 5,000–10,000 Vitamin A 15,000 IU/kg IU/kg Cholecalciferol (vitamin 500–1,000 IU/kg 500–1,000 IU/kg D3) Vitamin Eh 200 IU/kg 200 IU/kg a
Nutrient concentrations are recommended minimums for carnivorous reptiles and averages for omnivorous reptiles. b Nutrient levels expressed on a dry-matter basis. c Taurine requirements have not been determined for reptiles (the requirement for cats is 400–500 mg taurine/kg dry diet). d A dietary source of arachidonic acid at 200 mg/kg dry diet may be necessary. h 300 IU/kg dry matter is advisable if the diet is high in fat, especially unsaturated fat.
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Nutrition in Sub ungulates and Ungulates Hay comprises the bulk of the diet for most ungulates in captivity and should be available for most of the day rather than fed at intervals as meals. As a general rule, a leafy legume hay, eg, alfalfa, should be used for those species that are primarily browsers (eg, Giraffidae, Cervidae, sitatunga, bongo, duiker, tapir), whereas a goodquality grass hay is satisfactory for most grazers or bulk feeders (eg, zebra, elephant, bison, buffalo, wildebeest, camel). Legume hays are higher in nitrogen and calcium and are more digestible than grass hays. Hay should be leafy and green, free of mold, dirt, excess weeds, and other foreign matter, and should not be overmature. Low levels of calcium can cause poor bone calcification and also affect the calcium level in the blood, which can cause birth problems. 14
5. Precautions should be taken if feeding silage products. If the silage is not processed or stored properly or contaminated by animal or meat products, it may contain fungi or bacteria (eg, Clostridium botulinum) that can produce lethal toxins. 6. In addition to hay, a pelleted diet containing protein, minerals, and vitamins in concentrations adequate to meet the needs of domestic species and those wild species for which data is available can be offered. 7. Animals being fed as a group rather than as individuals, it is preferable to use a pelleted diet that is not excessively high in digestible energy (~3 kcal DE/g dry matter is suggested) and which contains sufficient fiber to support proper rumen or colon function. This precaution reduces the possibility of untoward effects (eg, rumen acidosis, colic, obesity) caused by overconsumption of concentrates. 8. A specialized pellet with high amounts of neutral detergent fiber (NDF) and acid detergent fiber (ADF) is recommended for browsers, and a pellet with moderate amounts of NDF and ADF is recommended for grazers. The intermediate feeding animals should get an equal mix of the browser and grazer pellets. Preferably, the diet of browsers should consist of equal parts of browser pellets, good palatable alfalfa, and browse. Diets for grazers and browsers should contain high amounts of vitamin E and biotin to prevent muscle dystrophy and hoof problems. 9. A ½ in. (~13 mm) pellet or cube size helps minimize waste when fed to larger perissodactyls and subungulates. 10. Commercial cattle products should not be fed to zoo herbivores, because vitamin E levels are very low and some products may contain nonprotein nitrogen sources such as urea that are not tolerated by hindgut-fermenting species (eg, equids). Also, the amount of easily digestible energy may be high, leading to obesity. Tapirs should get a mixture of grazer and browser pellets combined with some greens, alfalfa, and browse. 11. As a general rule, most large ungulates (>250 kg) consume 1.5–2% of their weight in dry matter daily. Smaller species (<250 kg) generally consume 2–4%. Offering a pelleted diet at 10–30% of the dry-matter intake is adequate for most grazers if good-quality hay is fed. The amount of minerals and vitamins should be balanced in the pellets in such a way that the total diet (including greens, browse, and hay) should be adequate. When hay quality declines, or for more delicate species, the percentage of high-fiber pellets should be increased. 12. Hay should be fed from a rack rather than off the ground for most species (elephants are an exception). Hay racks should be located at eye level for tall browsers such as giraffes and gerenuks. 13. Pellets can be offered from a covered trough or rubber feed pans. If possible, animals should be fed separately to ensure that each individual receives a similar amount of food. If feeding separately is not possible, at least 2 widely separated feeding stations may be necessary to reduce conflict and to ensure that subordinate animals obtain their share of food. 15
14. In addition to hay and pelleted diet, assorted fruits and vegetables often are fed to exotic ungulates. For most species, these items usually are not necessary except as an occasional treat; the amount should be limited to ~15–20% of the total diet. The exception might be for those species that regularly feed on fruits and succulents in the wild. It may be advisable to include some greens and vegetables (~0.5 kg/100 kg body wt) in the diet of species such as okapi, duikers, dik diks, bongo, and tapirs. 1. 2. 3. 4. 5. 6.
7.
Nutrition in Bats Captive insectivorous bats frequently are fed diets consisting primarily of mealworms apart from crickets, fruit flies, blowfly larvae, and other insects. Diets containing / based on insects diets are low in calcium. Calcium and vitamin supplements can be dusted on the insects just before feeding, and vitamin drops can be added to drinking water. Gels containing water and a calcium solution can also be fed. Suitable mealworm diet can be formulated using 35% wheat middlings, 35% ground dry dog or cat food, and 30% ground calcium carbonate. Insectivorous bats must be fed frequently by hand when flying insects are not available. Some bats can be trained to accept insects from a food dish by being placed directly on the live food. Many of the insectivorous bats can be maintained successfully in captivity using artificial liquid or solid diets. Liquid diet can be placed in shallow plastic trays positioned near wire or branches for the bats to land on and hang from while feeding. Leftover liquid diet should be replaced daily. Solid diets usually include bananas as the major ingredient. Additional ingredients frequently offered include papaya, apple, pear, melon, grape, and cooked carrot and sweet potato.
Nutrition in Zoo Carnivores: Exotic felids, canids, mustelids, viverrids, procyonidae, hyaenidae, ursidae Feeding: 1. Most zoos use nutritionally complete commercial diets for feeding carnivores, rather than attempting to prepare diets in-house. In some whole or a part of a carcass (eg, of buffalo) may regularly be fed. Other prey animals, such as rabbit and chicken, are also regularly offered. 2. A supplement containing a minimum calcium, vitamin A, iodine, taurine, and some B vitamins should be added to the meat diet. 3. Feeding a complete mixed diet greatly reduces the incidence of nutritional problems in captive exotic carnivores; however, such a diet regularly causes stool problems 4. Exotic feline diets are usually higher in fat, protein, and vitamin A than canine diets. A diet suitable for most cat species contains 45– 50% protein, 30–35% fat, 3–4% crude fiber, 1.2–1.5% calcium, 1– 1.2% phosphorus, and 20,000–40,000 IU of vitamin A/kg diet (drymatter basis). 16
5. Exotic cats, like domestic cats, cannot convert carotene to vitamin A, tryptophan to niacin, and linoleic acid to arachidonic acid. They also cannot synthesize adequate taurine (a taurine deficiency has been reported in leopards) and would be susceptible to ammonia toxicity if fed an arginine-deficient diet. Therefore, these nutrients should be considered dietary essentials for all felids. 6. Beef shank bones for large cat species; oxtails, rib bones, or whole rodents for smaller cats. Mice, rats, and chicks for diets of smaller cats. Rodents, poultry, fish, and organ and chunk muscle meats can be offered as occasional treat items to administer medication or to stimulate appetite. 7. Canids can be fed frozen, canned, or dry canine diets. Bones should be included in the diet when soft foods are fed. Canids can be fed meat, with the right amount of vitamins and minerals added, varied with small prey animals like rats, mice, rabbits, and chicken. 8. Small amounts of fruits and vegetables can be included in the diets of foxes and coyotes. 9. Most mustelids and viverrids do well on a meat-based diet supplemented with vitamins and minerals. Many species accept small amounts of fruits, vegetables, and cooked egg. Mice, fish, and chicks can be offered as occasional treat items and to stimulate appetite and activity. Rib bones can be given twice weekly to promote dental health. Canned foods may be more palatable but are not recommended as a base diet, because ferrets may not be able to eat enough to meet their needs for calories and protein 10. Procyonids can be fed diets similar to those offered to small canids, or an adequate meat diet can be fed. Feeding dry dog food along with apple, banana, and carrot is satisfactory for raccoons and helps minimize obesity. The herbivorous food habits of the giant panda require large amounts of bamboo supplemented with highfiber diet. 11. Bears can be fed meat supplemented with vitamins and minerals, frozen canine diet, dry dog food, fish, and commercial omnivore biscuits. Polar and Kodiak bears do well on a diet of 25% frozen canine diet, 25% fish (eg, smelt), 15% dry dog food, 15% omnivore biscuits, 10% bread, and 10% apples. Bananas and green vegetables can be included in the diet sloth, spectacled, and black bears. Food intake of captive bears varies widely with the season. Intakes generally are maximal during summer and early fall and minimal during winter. It is advisable to feed extra cod oil to polar bears before their hibernation starts. Freshwater Otter Diet Ground horse or buffaloe meat Ground beef heart Ground dry cat food Beet pulp “Mirra Coat” Calcium carbonate Poultry fat Water
Percent (%) 38 20 13 2.9 1.9 0.8 4.9 16.9 17
Lactose 0.04 Yogurt 0.72 Mineral-vitamin mix 0.84 All ingredients should be combined in a large mixer, divided into daily portions, and frozen. Lactose for lactobacilli can be added in yogurt to help maintain freshness. Lactose and yogurt are optional Nutrition in Marine Mammals
Fish are the primary food of captive marine mammals except for the herbivorous sirenians (sea cow). The purchase and subsequent proper storage and handling of high-quality fish are the most important aspects of feeding cetaceans (whales; dolphins; porpoises; narwhals) and pinnipeds (seals, walrus, sea lions). 1. The regular diet of any marine mammal should consist of ≥2 fish species to help ensure a balanced diet. 2. Thiamine should be added (at 25 mg/kg fish, as fed daily) to any marine mammal feeding program because of the possibility of thiamine destruction by thiaminases that are found in several fish species. 3. Supplemental vitamin E helps compensate for oxidative destruction of natural vitamin E in fish during storage and helps protect against the deleterious effects of peroxides formed in stored fish. 4. Salt (NaCl) supplementation to pinnipeds maintained in freshwater is sometimes recommended to prevent hyponatremia; 3 g salt/kg fish should be adequate. 5. Food intake in marine mammals varies considerably, depending on fat content of fish, water temperature, and activity. Performing Atlantic bottlenose dolphins generally eat 7–10 kg fish/day. Adult seals and sea lions consume ~5–8% of their body wt in fish/day. 6. Captive sirenians can be maintained on a diet of lettuce, cabbage, alfalfa, and aquatic plants (eg, water hyacinth). Nutrition in Marsupials Didelphid marsupials, Dasyurids, Bandicoots, Wombats and the larger macropod marsupials Diets: 1. Green vegetables, carrot, sweet potato, apple, and banana can be fed to all herbivorous and omnivorous marsupials. 2. For herbivores, greens should be added in limited amounts; these marsupials should be fed good-quality hay. 3. To prevent lumpy jaw, the diet of marsupials should contain at least 200 mg vitamin E and 0.2 mg selenium/kg dry matter. 4. Captive koalas can be fed successfully only on leaves of certain species of eucalyptus. Nutrition in Primates 1. Processed products should comprise 50% of the dry-matter intake of most species; fruits and treat items should comprise ≤25%. Green vegetables and browse should be at least 25% of the diet, depending on the species. 18
2. High-quality protein diets with (20–25% crude protein) should be fed to New World primates. 3. Old World species such as gibbons, orangutans, chimpanzees, and gorillas need high-fiber products. 4. Cultivated fruits should be used sparingly for great apes and leafeating species because, compared with cultivated green vegetables, they have high levels of sugars and simple carbohydrates and are low in protein and calcium. 5. Other items commonly included in the diets are hard-boiled egg (if cholesterol is not a concern), yogurt, and bread. Grapes, raisins, peanuts, crickets, and mealworms are treat items fed 2 or 3 times a week at the most, not every day. The energy amount of these enrichment items should not exceed 5–10% of the energy consumed by the animal. 6. Sunflower seeds, instant rice, cracked corn, and shredded coconut can be scattered around the exhibit or holding areas to promote foraging activity. The amount of energy used for these enrichment feeds should not exceed 5–10% of planned dietary energy. Hay should be provided for nesting materials and diversion, and it can act as a foraging substrate. 7. Many zoos offer meat to great apes; although meat is relished it is not necessary if the diet is properly balanced. Because of hypercholesterolemia seen in captive gorillas, feeding of meat is contraindicated. 8. For most primates, meals should be offered at least twice daily. Smaller species even more frequent feedings. 9. New World primates use vitamin D2 poorly. It is particularly important that these species receive an adequate source of stabilized vitamin D3 (cholecalciferol) in their diet if they are not exposed daily to direct sunlight. 10. Marmosets require up to 4 times the amount of vitamin D 3 required by other New World primates. In noncommercial mixtures for smaller primates (mixtures of cut apples, bananas, and cereal products with vitamins and minerals added) vitamin D 3 should be included; however, care should be taken to prevent vitamin D toxicity. 11. Several cases of rickets in some Old World species at weaning have been reported due to replacement outdoor primate exhibits with more naturalistic, but indoor, exhibits. While most free-ranging primate species probably satisfy their requirement for vitamin D by exposure to ultraviolet B (UVB) from sunlight, captive animals rely entirely on a dietary source. Infants at weaning are at risk because milk levels of vitamin D are low, and many foods the young begin to eat are not fortified with this vitamin. 12. All primates require a source of vitamin C as the amount of vitamin C consumed via green vegetables, oranges, multiple vitamins, chocolate, fruit juice, or fruit-juice powders may not be sufficient. 13. Members of the subfamily Colobinae are perhaps the greatest challenge in proper feeding of captive primates. Pregastric fermentation, similar to that in ruminants, occurs in the complex 19
stomach of these species. In the wild, leaves form a major part of the diet of most colobines (the more frugivorous red colobus is an exception). Natural diets are high in fiber, and animals spend much time foraging. Also considerable percentage of colobus monkeys are sensitive to starch and gluten. 14. Preferably gluten-free, high-fiber diets with (25–50% neutral detergent fiber and up to 15–35% acid detergent fiber) are recommended for feeding captive colobines. A diet consisting of 40% of a palatable high-fiber biscuit and 60% green vegetables and fresh browse is recommended for most colobines. Adding apple sauce can increase palatability of the diet. In colobines, dietary changes always should be made gradually to allow their gastric micro flora time to adapt. Some of the nutrient requirements concentrations of Nonhuman Primates Nutrient Concentration Crude protein 15–22% Essential Ω-3 fatty acids 0.5% Essential Ω-6 fatty acids 2% Neutral detergent fiber 10–30% Acid detergent fiber 5–15% Calcium 0.8% Total phosphorus 0.6% Nonphytate phosphorus 0.4% Vitamin A 8,000 IU/kg Vitamin D3 2,500 IU/kg
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