Tegu Food Pyramid
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The pyramid is a guide to feed your tegu. You do not have to follow the schedule exactly (see special considerations). It is based off of research on the macronutrient and calcium requirements of various types of reptiles outlined in the Merck Veterinary Manual as well as individual scientific studies about wild tegu diets. This pyramid is also based off of what experienced tegu breeders have found to work for their animals.
The tegu food pyramid is designed to be a user-friendly guide. The diagram in the insect section shows how feeder insects should be properly gut loaded for a tegu. These amounts are proportioned by weight. The key on the right side describes how many times to feed this food group per a week. When the pyramid level is broken in half, you can choose either food group. The larger the section, the more important it is. |
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Introduction: |
This guide is made to combat the incomplete knowledge of tegu nutrition. Many new owners are confused about what to feed their pets while experienced owners are looking for the best diet possible.
There is no such thing as a complete guide to tegu nutrition because there is no realistic way for the in-home keeper to formulate a total diet. It is conventional wisdom that variety is the key to combat an incomplete diet, but that isn’t always the case. For example, almost all the foods a tegu is fed will be deficient in calcium and iodine. This is simply a product of commercial agriculture raising plants and insects so that they grow as cost effectively as possible. This guide will get you as close as possible to a complete diet without expensive scientific testing. The most important thing in any animal’s diet is feeding appropriate foods in appropriate ratios in order to get the correct balance of protein fat and carbohydrates. It will also help you understand other nutrients how to get them too. |
Key Food Groups:
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Meat:
Meat is source of protein for tegus, but is consumed less than insects in the wild (Kiefer and Sazima 2002, Sazima and D'Angelo 2013, Barraco 2015). The amount is meat found in the diet can vary widely between dietary studies but it is always considerably less than insect and arachnid consumption. Barraco (2015) found that 37% of diet samples contained vertebrates, 46% contained snails/slugs and 5% contained crustaceans. Similarly Kiefer and Sazima (2002) found snails/slugs and crustaceans to be in 20% and 6.7% of diet samples, respectivly. Types of vertebrates consumed varied greatly from study to study with Kiefer and Sazima (2002) finding frogs to be the most common, Sazima and D'Angelo (2013) finding rotting fish to the most common and Barraco (2015) finding rodents to be the most common. This indicates that tegus are highly adaptable to different diets and feed opportunistically. Vertebrate eggs can also make up a significant portion of the wild tegu diet. 32% of feedings observed by Sazima and D'Angelo (2013) were of bird or reptile eggs. 10% of diet samples of the Barraco (2015) study contained eggs. Whole prey items are the most nutritionally valuable foods for tegus. Rodents, chicks and whole trout are great meat options for tegus. Eggs are a good occasional choice for tegu food. Freshwater crustaceans and snails are an extremely healthy option for tegus. Saltwater crustaceans and snails can also be fed in moderation. Except in special cases (see special considerations section), all meat that is fed should be whole prey items. Items such as ground turkey are not nearly as beneficial to the diet as whole prey items. Insects (and arachnids): Insects are the main protein source for tegus. Insects were found in 76% of diet samples (Barraco 2015). Most commercially raised insects are deficient in several nutrients, including calcium, thiamin (vitamin B1), vitamin A and vitamin E. It is necessary to feed the insects a high calcium and vitamin A diet before feeding to your tegu. Gut loading is much more effective than dusting insects. The insects fed should also be low in fat content. Tegus eat a wide variety of "bugs" in the wild but the most frequently consumed "bugs" are spiders and the grasshopper family (Kiefer and Sazima 2002, Sazima and D'Angelo 2013, Barraco 2015). Ideal insects include crickets, roaches, hornworms and soldier fly larva (reptiworms). Insects that should be fed more sparingly due to their fat content include mealworms , superworms and waxworms. Check out the nutritional analysis of some common feeder insects. Insects' Diet- Gut Loading: Gut loading insects is critical for leopard geckos because all of their diet comes from insects. The food for gut loading should be 20% calcium, 50% greens, 10% vitamin/mineral supplement and 20% vegetables, by weight. This diet should be fed to the insects for at least 48 hours. This allows the body to absorb nutrients such as vitamin A. Calcium is not well consumed by insects, so in addition to feeding this gut load diet, insects should be dusted with a calcium powder. -Calcium (20% of gut loading diet): A calcium supplement should be purchased separately from a vitamin and mineral supplement. Almost all feeder insects are deficient in calcium and calcium is required more than any other mineral in reptiles. The calcium supplement fed to insects should include vitamin D3 to ensure that the insects can process the calcium. The calcium recommendations for gut loading are based on the Finke (2003) study that recommends 3-9% elemental calcium in a gut loading diet, depending on the insect species. Calcium carbonate (the most common calcium supplement) is 40% elemental calcium, thus 20% calcium supplement is needed in the diet. This recommendation is also backed up by Finke et al. (2005), which showed that 15% calcium carbonate supplementation to the gut loading diet increased the calcium content of small crickets from 0.2% to 1.1% calcium. Considering that the 20% calcium supplement amount is by weight, it actually won't appear to be as much calcium as you would expect. It is highly recommended you weigh out the ingredients in your gut loading diet. Due to palatability issues with simply adding a calcium powder to a gut load diet of fresh vegetables, insects should also be dusted with a calcium powder before feeding. It is unlikely that insects will consume enough calcium in a home-made gut load diet. For the tegus be sure that you have proper UVB lighting. Without UVB, tegus cannot process the calcium they are eating. -Vitamin/Mineral Supplement (10% of gut loading diet): A vitamin and mineral supplement is essential when feeding insects to ensure no nutrients are missing, however there is quite a variety of supplements on the market. When looking for a supplement for a healthy gut loading plan, as outlined here, there are a few key nutrients one should consider. Most insects are low in magnesium, iron, iodine and vitamin E. Make sure your supplement provides these nutrients as well as ample amounts of B vitamins. Often iodide is provided using kelp as an ingredient. Vitamin A is also a nutrient commonly lacking from commercially raised insects. A vitamin and mineral supplement can be used to help increase the vitamin A content of a gut loading diet, but if fed the correct vegetables in the gut loading diet, this is not required. Greens: Greens are a powerful source of nutrition for tegus. They also provide bulk and vitamins to a gut loading diet. Greens generally can be divided into three categories, staple, occasional rare and never foods. To make a green an every day green it must be rich in nutrients like calcium, low in phosphorus and low in anti-nutrients like oxalates and goitrogens. Occasional greens are rich in nutrients, but contain too high a level of oxalates or goitrogens to be feed every day. Rare greens have very high oxalates and goitrogens. They should be avoided. Never greens have high phosphorus, low calcium and sometimes have high oxalates. Staple greens are escarole, endive, alfalfa and dandelion greens. Occasional greens are bok choy, collard greens, mustard greens, turnip greens, watercress Rare greens are kale, dark lettuces, parsley, swiss chard, spinach Never greens are iceburg lettuce, cabbage Vegetables: This is the part of a tegu’s diet that will bring in a diversity of nutrients and flavors. In the wild, tegus are known to occasionally eat flowers (Kiefer and Sazima 2002). Vegetables are also critically important for gut loading as a source of beta-carotene, which is processed by the insects into retinol, a form of vitamin A that tegus can use. Good vegetables are often bright in color and not too high in oxalates and phosphorus. Sometimes the healthiest foods are also the strangest, such as prickly pear leafs and hibiscus flowers. Some of the best vegetables include acorn squash, butternut squash, bell peppers, prickly pear leafs, hibiscus, common button mushroom, okra, and pumpkin. Other good vegetables include asparagus, broccoli, brussel sprouts, carrot, green beans, snap peas, tomato, yellow squash and cucumber. Check out the nutritional analysis of vegetables. Fruit: Most of the vegetative matter that tegu's consume in the wild is fruit. 16.7% and 50% of dietary samples of tegus included fruit. These consisted of a variety of fruit including berries and palm fruit (Kiefer and Sazima 2002, Barraco 2015). In the wild, fruit can be up to 30% of the volume of the diet (Kiefer and Sazima 2002). Fruit is not a requirement in the wild diet as Sazima and D'Angelo (2013) observed no feedings on fruit or any other vegetative matter. It is important to remember that almost all fruit you can buy in the store is heavily domesticated and has little relation to the nutritional content of its wild relatives. Fruit fed to tegus should be kept to a limited amount of only highly nutritious varieties. Some healthier fruits include berries, cantelope, dates, figs, guava, kiwi, mango, oranges, papaya and pineapple. Sources: Barraco, Liz Anne, Risk Assessment of the Nonnative Argentine Black and White Tegu, Salvator merianae, in South Florida. Unpublished thesis from Florida Atlantic University. (2015). Finke, Mark D., Gut Loading to Enhance the Nutrient Content of Insets as Food for Reptiles: A Mathematical Approach. Zoo Biology. 22(2):147-162 (2003). Finke, Mark D., Shari U, Dunham and Christabel A. Kwabi, Evaluation of Four Dry Commercial Gut Loading Products for Improving the Calcium Content of Crickets, Acheta domestics. Journal of Herpetological Medicine and Surgery. 15(1) 7-12 (2005). Kiefer, Mara Cintia, and Ivan Sazima. Diet of Juvenile Tegu Lizard Tupinambis merianae (Teiidae) in Southeastern Brazil. Amphibia-Reptilia 23: 105-108 (2002). Sazima, Ivan and Giulia B. D'Angelo, Range of Animal Food Types Recorded for the Tegu Lizard (Salvator merianae) at an Urban Part in South-Eastern Brazil. Herpetology Notes. 6 427-430 (2013). |
Special Considerations:
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These dietary guidelines are designed for an average, healthy, tegu. As with anything, if your reptiles are ill you need to consult a veterinarian for advice. That being said, there are some normal dietary considerations that apply to many tegus. If your tegu is sick, please check out our diagnostics page.
Obesity: Many captive animals of all kinds suffer from obesity. The best thing you can do for an obese tegu is feed only lean insect species, exchange 20% of whole prey items for lean white meat such as chicken breast, and greatly reduce the portion of fruit in the diet. Obesity is deadly. It can cause liver failure and many other issues. Supplementing with a very small amount of omega 3 fish oil is also wise to prevent liver disease in obese animals. Juveniles: Young tegus are growing fast and need more protein and calcium than older tegus. In the wild is is likely that juveniles eat more insects than meats, however this is not necessary to replicate in captivity. Captive raised insects are low in calcium while vertebrate prey, such as pinky mice are a much better source. Juveniles may be less interested in eating plant matter. Make sure you feed lots of insects that are gut loaded with calcium and vitamin A as well as pre-killed vertebrate prey items that are small enough for a juvenile tegu to eat. Anorexia: Not eating is a common occurrence with many pet reptiles. Usually the issue is with the temperature of the enclosure, or another husbandry problem. Ensure that your tank is up to standards and visit a veterinarian. In the mean time, remember that eating any food is better than eating no food. Even if all your tegu will eat is berries this is better than not eating anything at all. Work on getting them to eat healthy foods, but again, unhealthy food is better than no food. For tips and tricks to get your animal to eat see our "appetite stimulation" page. |
Key Nutrients:
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There are many key nutrients in a tegu's diet. Calcium is a particularly important nutrient that many beginner keepers do not offer enough of. It is imperative to supplement your tegu with calcium and provide proper UVB lighting.
The key nutrients are listed in alphabetical order. Anthocyanin Definition-natural plant flavonoid pigments that appear blue or purple Function-a weak antioxidant Foods-acai, blood orange, blackberry, raspberry, blueberry, purple grapes Beta-carotene Definition-a red-orange pigment in plants that can be converted by some animals to vitamin A Function-A vitamin A supplement for omnivores and herbivores that cannot be overdosed as well as an antioxidant that enhances color Foods-carrot, pumpkin, sweet potato Calcium Definition-an abundant chemical element that essential for life Function-building blocks for bones and teeth and an essential element for cell physiology Foods-calcium carbonate supplement, mice, prickly pear leafs, oranges, soldier fly larva, bell peppers Carbohydrates Definition-a biological molecule made of chemically linked sugars. Carbohydrates include, sugars, starch and fiber Function-simple energy source for animals Foods-almost all foods, especially plants Copper Definition-a chemical element that is an essential mineral Function-Copper has many functions, including collagen formation, enzyme cofactors, incorporating iron into red blood cells and generation of energy from carbohydrates. It is usually abundant in foods for tegus and inhibits zinc uptake, so copper intake needs to be limited. Foods-spinach, turnip greens. asparagus, beans, nuts, kale, mushroom, pumpkin Fats (lipids) Definition-a biological molecule that is found in plants and animals Function- a dense energy source and an energy storage method Foods-waxworms, superworms, mealworms, nuts, seeds, mice Fiber - Click Here for More Information Definition-a type of complex carbohydrate in plants that cannot be digested Function-Fibers add bulk to the stool and give food for gut bacteria Foods- all vegetables and fruit Goitrogens Definition-substances that disrupt the production of thyroid hormones Function-These anti-nutrients should be avoided in excess in order to maintain thyroid health of tegus. They are less harmful when proper iodine supplementation is provided. Foods-cassava, soy, peanuts, strawberries, spinach, bok choy, broccoli, cabbage, kale, turnip Iodine Definition-a chemical element abundant in the ocean that is an essential mineral Function-key component of hormones made by the thyroid Foods-kelp, ocean fish, shrimp, spirulina, scallops, standard table salt Macronutrient Definition- A category of nutrients that makes up the bulk of foods. It includes protein, fat(lipids), carbohydrates and water. Function-each macronutrient has a different function, but protein, fat(lipids) and carbohydrates can all provide energy. The ratios of these nutrients in a diet is extremely important. Foods-all foods Minerals (dietary) Definition-a chemical element that is required by living organisms other than carbon, hydrogen, nitrogen and oxygen Function-builds bones, tissue, catalyzes biological reactions, transports oxygen and many more Foods-all foods have some mineral content Oxalates Definition-a specific organic acid found in plants and animals Function-binds with calcium to form kidney stones and prevent calcium from being used in the body Foods-soy, nuts, beans, spinach, swiss chard, beets, collard greens, okra, blueberries, grapes, raspberries Phytonutrients Definition-chemicals naturally produced by plants that are not of conventional nutritional value Function-functions vary but they are usually antioxidants, anti-inflammatory and promote liver health Foods-plants, especially ones rich in color Protein - Click Here for More Information Definition-a biological molecule made of chemically linked amino acids Function-maintains the structure of the body and excess can be used as an energy source Foods-all foods have some protein, with insects, crustaceans, mollusks and mice being especially high as well as a decent amount of protein in nuts and seeds Phosphorus Definition- an abundant chemical element that essential for life Function-enables cell function and builds bones, but is easily consumed in excess in a tegu’s diet. Excess consumption impairs calcium absorption and can cause muscle disorders. Foods-asparagus, beans, soy, seeds, cricket, mealworms, mushroom Vitamins Definition-A vital organic compound that an organism cannot synthesize on its own. They can be divided into fat soluble and water soluble. Function-each vitamin has its own function in the body Foods-all foods Vitamin A Definition-a group of related fat-soluble nutrients (carotenoids and retinoids) that are essential for the body. Function- Carotenoids come from plants and cannot be overdosed, so they are the safest form of vitamin A, however it is not known if tegus can convert carotenoids to retinoids. Vitamin A is needed for immune responses, night vision and many other functions in the body. Foods-egg yolk, turkey liver, whole prey Vitamin D Definition-a fat soluble vitamin derived from UVB light or dietary sources Function- needed to absorb calcium and other minerals from food Foods-UVB lighting should be provided for tegus so that they can synthesize vitamin D. Vitamin E Definition-a fat soluble vitamin that acts as a powerful antioxidant Function-protects against free radical damage, ageing and heart disease. It is especially crucial in a high fat diet. Most foods high in vitamin E are also high in fat, so a balance is difficult to achieve. Foods-sunflower seeds, shrimp, greens. almonds, broccoli |
Science Behind the Pyramid:
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The proportions of the pyramid are based on macronutrient balancing. According to the Merck Veterinary Manual, omnivorous reptiles need a diet of 20-25% protein, 3-6% fat and 20-35% fiber on a dry matter basis. According to this manual carnivorous reptiles need 30-50% protein. Considering tegus are almost carnivorous the target for protein is at least 30%. To achieve these macronutrient ratios the pyramid recommends how often to feed a portion of insects, meat, greens, or vegetables. There is a total of 10 portions of these food groups fed each week.
2 fruit portions/ 8 total portions= 25.0% fruit .5 greens portions/8 total portions=6.3% greens .5 vegetable portions/8 total portions=6.3% vegetables 4 insect portions/8 total portions=50.0% insects 1 meat portions/8 total portions=12.5 % meat The most important macronutrient is protein. The diet aims to achieve a >30% dry matter protein content. Fruit, greens, vegetables, insects and meat are typically 5%, 20%, 10%, 50% and 60% protein, respectively. Multiplying the % of protein by the proportion of portions gives us: .25x5%+.063x20% + .063x10% + .50x50% + .125x60% = 35.6% protein Therefor this food pyramid provides an adequate amount of protein. Using this same method fat and fiber can also be calculated. Fruit, greens, vegetables, insects and meat are typically 2%, 2%, 2%, 18% and 20% fat, respectively. They are typically 15%, 25%, 25%, 10% and 2% fiber, respectively. .25x2%+.063x2% + .063x2% + .50x18% + .125x20%= 12.3% fat (goal 3%-6% omnivores, much higher for carnivores) .25x15%+.063x25% + .063x25% + .50x10% + .125x2%= 12.1% fiber (goal 20%-35%, lower for carnivores) |