May 29, 2002

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NUTRIENT COMPOSITION OF WHOLE VERTEBRATE PREY

(EXCLUDING FISH) FED IN ZOOS

Ellen S. Dierenfeld, PhD Heather L. Alcorn, BS Krista L. Jacobsen, MS

Animal Health Center Dept. of Animal Science Animal Health Center

Wildlife Conservation Society Cornell University Wildlife Conservation Society

Bronx, NY 10460 Ithaca, NY 14853 Bronx, NY 10460

Although nutritionally balanced formulations, largely based upon nutrient requirements of

domestic cats, are commercially available for many zoo carnivores, some choose to use

whole prey as a part or all of certain captive feeding programs. Whole prey are similar in

physical form to the natural diet of some carnivores, and are commonly presumed to meet

nutrient requirements as long as nearly all soft tissues and some bones (or other calcified

tissues) are consumed. This use has the potential to positively influence behavior, and may

have positive, indifferent, or negative effects on health. Prey sizes offered are commonly

related to consumer body size. Prey species offered tend to relate to documented or

perceived natural feeding habits and/or individual animal preferences. Little consideration has

been given to differences in nutrient composition associated with prey species, age, sex, and

diet.7,14,15 Further, origin, handling, and storage methods influence the nutritional value and

healthfulness of prey. These issues, as well compositional data, are discussed in the following

sections.

Sources, Receipt, Handling, and Storage of Prey

Whole prey items, when used, often constitute the most expensive part of a carnivore diet.

Thus, it is important that methods of procurement, receipt, handling, and storage preserve

their nutritional value and maximize the benefits of their use.

Sources

A partial list of whole prey vendors is provided in Appendix 1 (inclusion does not necessarily

imply endorsement). Additionally, local research facilities are sometimes willing to donate

laboratory animals to zoos as food for carnivores.

Prey suppliers should house, manage, and ship their animals in conformity with the

Animal Welfare Act (Public Law 89-544), first passed in 1966 and amended in 1970, 1976,

1985, 1990, and 2002 (see http://www.aphis.usda.gov/ac). Medical care of prey species

should be appropriate to ensure that these animals will not be a source of parasites and

infectious diseases.16 If animals are killed before shipment, techniques recommended by the

AVMA Panel on Euthanasia3 to minimize pain and distress should be used. Of course, the

euthanasia technique chosen must not leave a residue that may harm the prey consumer.
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Standing orders for vertebrate prey (either live or frozen) help assure a constant

supply since the supplier is able to regulate breeding schedules to meet anticipated demand.

Live animals from vendors are commonly shipped via United Parcel Service (UPS), or other

ground mail services, and upon occasion may be exposed to adverse environmental

conditions. If animals are shipped frozen, potential problems parallel the shipment of other

frozen items.

Inspection upon receipt

Upon receipt, a shipment should be examined visually for signs of damage or poor handling.

Live animals should have been supplied with food and water and should appear comfortable,

without evidence of overheating (such as panting or prostration) or excessive cold exposure

(huddled in groups). If there is a problem related to package handling, this should be

addressed with a representative of the transport company at the time of receipt. Persistent

shipment problems should be discussed with the prey vendor so a different transport company

may be chosen, if necessary.

Frozen shipments should not show evidence of thawing during transport (such as free

moisture, ice crystals on the prey, appearance or odor of spoilage). Once frozen, prey should

not be allowed to thaw until needed. While vacuum packaging prolongs the storage life of

frozen meat and poultry for human consumption,35 specific studies with frozen whole prey

have not been conducted to determine whether this packaging would be beneficial for

zoological institutions.

Periodic chemical evaluations of quality will help ensure that the prey animals have

been properly nourished. As a minimum, whole prey should be analyzed for percent water

(conversely, dry matter), crude protein, crude fat, and ash. Mineral and vitamin analyses can

provide additional valuable information. Protocols for sampling and a discussion of

appropriate analytical techniques are presented in NAG Fact Sheet 010 (Quality Control of

Feedstuffs: Chemical Analysis).

When prey are purchased by number, the number of animals delivered should be

counted. With the best of intentions, mistakes in types or amounts of product shipped can

occur. A log documenting lot number, type of whole prey, quantity, and quality should be

maintained. This log can help trace problems to particular vendors and can supply

information on the quality of handling prior to receipt. When prey are ordered through a bid

system, this documentation may be the minimum needed to remove an unacceptable vendor

from the bid list.

Storage

Whole prey items that arrive frozen should be handled similarly to frozen meat and fish

products. Upon receipt, all frozen items should be immediately placed in a freezer at an

average product temperature of –18o to –30o C, or, if being thawed for feeding the following

day, in a refrigerator at a temperature of 2o to 3.5o C. Note, however, that the feeding of

frozen and/or partially frozen whole prey can provide improved gum stimulation, less

potential for bacterial growth, tends to slow ingestion, and is less smelly. Regardless of

whether fed thawed or frozen, all items should be well covered with moisture-impermeable
May 29, 2002

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plastic to reduce dehydration during storage. Stock should be rotated so that the oldest items

will be used first, thus ensuring that storage length times will be kept to a minimum.

Live animals that have been purchased for use as prey should be housed, fed, and

euthanized in conformity with the Animal Welfare Act and the recommendations of the

AVMA Panel on Euthanasia referred to as referenced above.

Related issues

Upon occasion, road-killed animals have been used as food for captive carnivores. This is a

practice that is discouraged. Uncertainty concerning prior health status, and spoilage

following death, make such a practice very risky. Sick animals or animals that have died of

illness or unknown causes, of course, should not be used for carnivore food. Further, if

muscle only is fed, it does not constitute a nutritionally complete diet, being particularly

deficient in calcium. Proper diets for large felids in institutions subject to federal inspection

are discussed to a limited extent in USDA/APHIS Policy #25 (http://

www.aphis.usda.gov/ac/policy/policy25).

Composition of Prey

Tables 1-3 summarize published data on nutrient composition of various species of whole

vertebrate prey (excluding fish) fed in zoos. Additionally, unpublished information was

requested from the international zoo community and is reported separately in Tables 4-6.

Specific nutrients and nutrient interactions warranting further investigation are suggested.

Values are expressed as weighted means, or raw means when n was not stated. Ranges,

standard deviations, standard errors, or coefficients of variation are not given, although there

may be considerable variation among individual values. Examination of the original

reference(s) is encouraged.

Proximate fractions (Tables 1 and 4)

Water. Whole prey may comprise the primary or only source of water for many

carnivores in nature. [Note: the AWA requirements include potable drinking water for

regulated animals. Although the animal may chose not to drink, water should be provided

separately at all times.] Species included in this summary contain 60 to 85% water, on an asfed basis, with a modal range of 70 to 75%. As is typical for other studied species, water

content decreases with age, while energy density increases.

Protein. Lean (protein) and fat, as fractions of whole body mass, are inversely

related. Overall, whole prey fed to captive carnivores provide crude protein in excess of the

estimated requirements of domestic carnivores. Protein and essential amino acid

requirements of zoo carnivores have not been determined, and reports on the amino acid

composition of whole prey are very limited.25 Given the high concentration of protein in

prey, and the lack of reports of overt amino acid deficiencies, it is probable that amino acid

requirements will be met.
May 29, 2002

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Fat. The crude fat content of most whole prey is much higher than the recommended

minimum dietary levels (approximately 5 to 10% of dietary DM) for domestic carnivores.22,23

Neonates have lower body fat concentrations than do older prey animals, and skinned,

eviscerated carcasses contain lower fat concentrations than do the whole bodies of prey

animals of the same age. Amphibians, in general, contain lower body fat concentrations than

do mammals or birds. Most laboratory-reared rodents contain more body fat and less body

protein than sampled free-ranging rodents of the same species,6 perhaps due to energy-dense

captive diets and limited exercise.

Although prey body fat is a source of readily available energy for zoo carnivores,

essential fatty acid requirements appear not to have been determined. Minimum dietary

requirements of domestic cats for linoleic and arachidonic acids have been set at 0.5 and

0.2% of DM, respectively.23 Requirements for ω-3 fatty acids, such as α-linolenic or longerchain fatty acids, have not been defined. Assuming that zoo carnivores have fatty acid

requirements similar to those of the domestic cat, the few studies in which fatty acid

composition of whole prey has been reported9,11,23 suggest that essential fatty acid supplies

would be adequate. However, peroxidation during extended or improper storage of prey

may result in declines in essential fatty acid activity and destruction of vitamin E.9

Ash. Mineral concentrations in whole prey vary considerably, depending upon prey

type and, to some extent, age. Neonates often, but not always, contain a lower proportion of

total ash compared with adults. Data for some samples are reported as a fraction of “dressed

carcass”, with head, skin, and viscera removed and with bones remaining. Hence, ash

concentration is a higher fraction of carcass dry matter than of the intact body. Specific

mineral concentrations in relation to the dietary requirements of carnivores are discussed

below.

Fat-soluble vitamins (Tables 2 and 5)

Vitamin A. Vitamin A concentrations tend to increase with age/maturity in

vertebrate prey through accumulation in body stores.7,15 The liver is the major vitamin A

storage organ for those species that have been studied, and liver vitamin A concentrations

vary with carotenoid and vitamin A intake. Thus, body vitamin A stores also would be

expected to vary with levels of carotenoids and vitamin A in the diets of prey. Adult

laboratory-reared rodents, such as rats and mice, appear to contain higher levels of vitamin A

than do free-ranging rodents, such as prairie dogs. Species differences in vitamin A

concentration are apparent even within broad taxonomic categories, but all whole prey

analyzed to date would appear to exceed the dietary requirements of domestic dogs22 and

cats23 (approximately 4,000 IU/kg DM) without a need for further supplementation. In fact,

some of the concentrations reported approach or exceed presumed upper safe limits for this

nutrient (33,000 IU/kg DM for dogs to 100,000 IU/kg DM for cats).24

Vitamin E. Vitamin E concentrations in the whole prey species that have been

analyzed meet the estimated requirements of dogs22 and cats23 (about 30 IU/kg DM) when

fed diets with moderate levels of polyunsaturated fatty acids (PUFAs). High dietary levels of

PUFAs may increase the vitamin E requirement fivefold. Vitamin E deficiency, adversely

impacting reproduction and health, has been documented in raptors fed whole quail. It was

necessary to feed the prey quail approximately 200 IU vitamin E per kg dietary DM to
May 29, 2002

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provide adequate levels of this nutrient to the secondary consumer.12 Clear species

differences in vitamin E metabolism/utilization have been shown between laboratory mice and

rats raised on the same diets,7,15 suggesting that species that have not been studied may have

different requirements. In addition, vitamin E requirements for optimum function of the

immune system appear to be higher than levels needed to prevent the usual signs of

deficiency, at least in rats and humans.5;20

Minerals (Tables 3 and 6)

Macrominerals. Macromineral requirements (as a percentage of dietary DM) for

growing mammal and bird species (Ca, 0.4 to 1.2%; K, 0.2 to 1.4%; Mg, 0.03 to 0.1%; P,

0.3 to 0.6%; and Na, 0.05 to 0.4%) appear to be met by any of the whole prey in this report.

Calcium requirements for maximal egg production of indeterminate layers (no seasonality nor

fixed limit to egg production) such as leghorn chickens (2.25 to 2.75% of dietary DM)25

would be met by consumption of adult rodents, birds, reptiles, and amphibians, and it is

probable that the Ca requirements of determinate layers (limited egg production) such as

large raptors are lower.29

Trace minerals. Much variability among and within prey species in trace element

composition is apparent. There are several possible reasons for this, including the influence

of differing dietary trace mineral levels, species specific metabolism, varying accuracy of

analytical techniques, and contamination of analytical samples. Mean copper concentrations

range from about 2 to over 100 mg/kg of DM. Dietary requirements for copper (DM basis)

are estimated to be 2.9 mg/kg for dogs,22 5 mg/kg for cats,23 8 mg/kg for chickens,25 and 3-6

mg/kg for swine.26 Considering the high bioavailability of copper in unprocessed animal

tissues,2 it is likely that requirements would be met by all prey items. However, it may be

prudent to exercise caution in exclusive use of some high-copper prey as food for carnivores.

Iron requirements of the above species (32 to 110 mg/kg dietary DM) would probably

be met by all prey, although some whole prey may contain inappropriately high levels of iron

for individuals with a tendency to develop iron-storage disease.29

Recommended dietary levels of bioavailable zinc (10 to 50 mg/kg DM) would be met

by most whole prey and are higher in free-ranging rodents compared with laboratory-reared

mice and rats.14

Estimated manganese needs of dogs22 and cats23 (5 mg/kg dietary DM) would

probably be met by most whole prey. The issue of bioavailability2 is relevant here, and poor

availability of manganese in some plant products is responsible for the elevated requirement

of this nutrient in natural-ingredient chicken diets (up to 66 mg/kg DM).25 Manganese

requirements of chicks fed a semipurified dextrose-casein diet was estimated to be about 15

mg/kg DM.32 The manganese requirements of carnivorous birds have not been determined,

but evidence of manganese deficiency in raptors consuming whole prey in the wild has not

been reported.

Data Gaps
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Information on concentrations of fatty acids, vitamins D and K, the water-soluble vitamins,

and essential amino acids in whole prey is lacking. The data that are available suggest that

larger, physiologically more mature prey may constitute a very different diet for prey

consumers, in terms of nutrient content, than smaller specimens of the same species.

Likewise, different species of the same class of prey items may differ considerably in chemical

and nutrient content, with much of this difference determined by the diet consumed. Diets

fed to prey species that are intended as food for carnivores should be carefully assessed with

respect to nutrient content, interactions, and persistence in tissues. In particular, the

concentrations of fatty acids, fat- and water-soluble vitamins, and trace elements in diets fed

to prey, and their effect upon prey composition, require further investigation. Such

information should be considered integral to the development of optimal diets for whole prey

used as food for other species, and all should be considered when assessing the adequacy of

carnivore diets. Based upon current body composition data, additional macromineral and/or

vitamin A supplementation of whole prey-based diets appears unwarranted.

Acknowledgments

The authors wish to thank Katie Carroll for editorial assistance, and numerous students and

colleagues for contributing to the data contained in this report. Review comments from Dr.

Charles T. Robbins and other colleagues of the American Zoo and Aquarium Association’s

Nutrition Advisory Group (NAG) improved earlier drafts of this document, as did the final

review of Dr. Barbara A Kohn, APHIS, USDA.

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May 29, 2002

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Table 1. Proximate composition and energy content of whole prey on a dry matter (DM) basis. Values expressed as weighted means

or as raw data when “n” was not stated. 

Prey species n DM Crude protein Crude fat Ash Gross energy Notes References

 % % % % kcal/g 

MAMMALS

Calf, Holstein 72 22.5 60.0 8.9 16.0 4.08 Fetal age, 190-270 days 4

Deer, white-tailed 22.3 80.7 6.3 17.9 4.62 Neonatal 29

Deer, white-tailed 22 36.9 57.0 24.5 13.8 5.63 Juvenile, ingesta-free 19, 39

Deer, white-tailed 6 41.1 47.4 41.4 11.4 6.34 Adults, ingesta-free 28

Guinea pig 29.1 51.2 34.7 14.1 5.95 Neonatal males 7

Guinea pig 6 31.3 51.4 46.1 9.2 6.99a Males, 10 week 7

Hamster 6 30.3 49.8 34.7 7.5 5.98 Juvenile 34

Hare, snowshoe 28.0 73.0 2.9 17.5 4.66 28

Mink 18.0 72.8 11.7 10.0 5.39 Neonatal 27

Mouse, domestic 287 19.1 64.2 17.0 9.7 4.87a Neonatal, <3 g 9, 13, 15

Mouse, domestic 292 18.2 44.2 30.1 8.5 6.65aJuvenile, 3-10 g 9, 13, 15

Mouse, domestic 108 32.7 55.8 23.6 11.8 5.25a Adult or >10 g 6, 7, 9, 13, 15

Mouse, jumping 29.7 62.9 18.7 12.9 5.50 28

Mouse, old-field 44 17.4 70.3 8.6 11.3 4.60a Neonatal 15

Mouse, old-field 171 29.8 54.6 21.9 10.7 5.29aJuvenile 15

Mouse, white-footed 34.1 59.7 19.9 12.9 5.51 28

Pig, domestic 32 28.9 50.7 33.2 11.9 5.78 Juvenile 31

Rabbit, black-tailed jack 3 27.0 74.4 4.5 15.0 4.54 Dressed carcass 28

Rabbit, domestic 15.4 72.1 13.0 14.9 5.06 Neonatal 27

Rabbit, domestic 2 26.2 65.2 15.8 3.4 5.30 Dressed carcass 27

Rat 5 20.8 57.9 23.7 12.2 5.30a Neonatal, <10 g 15

Rat 5 30.0 56.1 27.5 14.8 5.55aJuvenile, 10-50 g 15

Rat 51 33.9 61.8 32.6 9.8 6.37a Adult or >50 g 6, 7, 15
May 29, 2002

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Table 1 continued. Proximate composition and energy content of whole prey on a dry matter (DM) basis. Values expressed as

weighted means or as raw data when “n” was not stated. 

Prey species n DM Crude protein Crude fat Ash Gross energy Notes References

 % % % % kcal/g 

Squirrel, fox 17.6 55.7 NAb NA 4.89 Neonatal 28

Squirrel, gray 33.3 62.4 18.4 11.6 5.54 27

Vole, bank 15.5 63.2 24.5 10.3 5.68 Neonatal 28

Vole, common 16.5 64.2 16.4 12.7 4.97 Neonatal 28

Vole, meadow & red-backed 32.0 62.5 15.5 13.5 5.34 27

BIRDS

Chicken 66 25.6 64.9 22.4 6.4 5.80 One-day-old 6, 34

Chicken 16 32.5 42.3 37.8 9.4 5.90a Adult 6, 13

Duck, mallard 3 33.1 63.1 26.4 9.5 5.92 Dressed carcass 33

Quail, Japanese 18 34.6 71.5 31.9 9.9c 6.79a 7

REPTILES & AMPHIBIANS

Frog, Cuban tree 19 26.6 NA 4.8 NA 1

Frog, green 7 22.5 71.2 10.2 NA 4.80a30

Gecko, fox 5 25.3 NA NA NA 1

Lizard 151 28.8 NA NA 15.9 5.50d Nineteen species 38

Lizard, anolis 13 29.4 67.4 NA NA NA Adult 8

Lizard, bearded dragon 17 17.9 63.6 NA NA NA Various ages 8

Snake 4 28.0 NA NA 17.0 6.51dFour species 38

Toad, southern 1 26.4 61.8 13.7 NA 4.61aJuvenile 30

Toad, southern 4 28.2 61.0 14.0 NA 4.25a Adult 30 

Dressed carcass = eviscerated whole body with head, feet, and skin removed.

aCalculated by adding the product of % crude protein x 5.43 kcal/g to the product of % crude fat x 9.11 kcal/g.29

bNot analyzed.

c

Fat-free basis.

dAsh-free basis.
May 29, 2002

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Table 2. Vitamin A and E content of whole prey on a dry matter (DM) basis. Values

expressed as weighted means or as raw data when “n” was not stated. 

Prey species n Vitamin A Vitamin E Notes References

 IU/kg IU/kg 

MAMMALS

Guinea pig 6 16,506 24.2 Males, 10 week 7

Mouse, domestic 6 35,533 52.7 Neonatal, <3 g 15

Mouse, domestic 17 30,888 173.9 Juvenile, 3-10 g 15

Mouse, domestic 24 578,272 100.4 Adult or >10 g 7, 15

Prairie dog, black-tailed 30,830 82.6 Mean of range 27

Prairie dog, white-tailed 16,000 88.5 Mean of range 27

Rabbit, domestic 2 6,200 NAa 27

Rat 5 21,333 470.4 Neonatal, <10 g 15

Rat 24 151,389 139.2 Adult or >50g 7, 15

BIRDS

Chicken 6 35,600 51.3 Males 13

Quail, Japanese 18 70,294 66.8 Diet effects 7

REPTILES & AMPHIBIANS

Frog, green 7 25,110 82.2 30

Lizard, anolis 19 4,880 44.8 Adult 8

Lizard, bearded dragon 15 38,562 95.5 Various ages 8

Toad, southern 1 15,940 231.8 Juvenile 30

Toad, southern 4 38,261 369.0 Adult 30

aNot analyzed.
May 29, 2002

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Table 3. Mineral content of whole prey on a dry matter (DM) basis. Values expressed as weighted means or as raw data when “n”

was not stated. 

Prey species n Ca P Mg Na K Cu Fe Zn Mn Notes References

 % % % % % mg/kg mg/kg mg/kg mg/kg 

MAMMALS

Calf, Holsteina72 4.12 2.88 0.12 0.97 0.86 1.8 37.8 16.3 0.3 Fetal age 17

 190-270 days

Deer, white-tailed 6 4.82 2.49 0.12 0.20 0.54 5.0 81.1 65.6 NAb Juvenile, ingesta-free 19

Deer, white-tailed 3.09 2.26 0.19 0.39 0.95 26.1 164.5 68.4 28.5 Adult, ingesta-free 40

Guinea pig 6 3.02 NA 0.07 NA NA 5.6 56.4 46.4 6.6 Males, 10 week 7

Hamster 6 2.51 2.03 0.12 0.46 0.88 12.0 237.0 94.0 45.0 Juvenile 34

Mouse, cotton 4.05 1.67 0.12 0.24 NA NA 200.0 98.0 NA 29

Mouse, domestic 5 1.17 NA 0.11 NA NA 19.2 181.3 82.5 0.2 Neonatal, <3 g 14

Mouse, domestic 5 1.47 NA 0.09 NA NA 13.4 153.6 75.4 13.1 Juvenile, 3-10 g 14

Mouse, domestic 78 2.98 1.72 0.16 NA NA 6.7 137.9 67.5 7.7 Adult or >10 g

6,7,13,14

Mouse, golden 3.74 1.92 0.14 0.36 NA NA 240.0 110.0 NA 29

Mouse, old-field 1.60 1.86 0.06 0.43 1.20 NA 208.5 125.0 10.6 Mean of range 29

Prairie dog, black-tailed 1.54 1.14 0.07 0.26 0.47 5.0 215.0 75.0 3.5 27

Rabbit, domestic 2 5.93 3.43 0.18 0.26 0.72 4.6 100.0 84.0 2.4 27

Rat 5 1.85 NA 0.14 NA NA 60.6 275.8 113.6 6.2 Neonatal, <10 g 14

Rat 10 2.07 NA 0.12 NA NA 11.3 133.2 81.9 2.6 Juvenile, 10-50 g 14

Rat 49 2.62 1.48 0.08 NA NA 6.3 148.0 62.1 11.0 Adult or >50 g 6, 7,

14 Shrew, short-tail 3.44 1.72 0.14 0.42 NA NA 500.0 120.0 NA 29

Squirrel, fox 2.56 1.30 0.13 0.84 1.07 NA NA NA NA Mean of range 29

BIRDS

Chicken 66 1.69 1.22 0.05 0.71 0.80 5.2 119.5 97.4 3.9 One-day-old 6, 34

Chicken 16 2.22 1.40 0.50 NA NA 3.6 122.2 116.1 10.1 Adult 6, 13

Goldcrest 2.84 1.88 0.11 0.40 0.58 NA NA NA NA 29
May 29, 2002

13

Table 3 continued. Mineral content of whole prey on a dry matter (DM) basis. Values expressed as weighted means or as raw data

when “n” was not stated. 

Prey species n Ca P Mg Na K Cu Fe Zn Mn Notes References

 % % % % % mg/kg mg/kg mg/kg mg/kg 

Pipit, meadow 2.04 1.65 0.13 0.83 1.28 NA 400.0 107.0 13.5 Mean of range 29

Quail, Japanese 18 3.43 NA 0.06 NA NA 2.6 74.9 53.0 6.4 7

Rook 2.04 1.75 0.09 0.45 0.94 11.0 475.0 96.5 31.0 Mean of range 29

Tit, blue 3.28 2.04 0.10 0.37 0.58 NA NA NA NA 29

Tit, coal 3.31 2.08 0.11 0.39 0.63 NA NA NA NA 29

REPTILES & AMPHIBIANS

Frog, Cuban tree 19 4.79 2.57 NA NA NA NA NA NA NA 1

Frog, green 7 4.29 1.87 2.47 0.55 NA 11.2 102.6 100.3 11.5 30

Gecko, fox 5 5.22 2.18 NA NA NA NA NA NA NA 1

Lizard, anolis 13 5.54 2.88 0.15 0.33 0.73 5.0 127.8 142.5 4.0 Adult 8

Lizard, bearded dragon 18 3.53 2.35 0.16 0.66 1.12 8.9 276.4 133.3 9.3 Various ages 8

Tadpole, bullfrog 2.60 NA 0.68 NA 0.18 3.3 NA 19.3 59.0 10

Toad, southern 1 5.16 2.68 0.07 0.36 NA 127.0 294.7 471.6 11.1 Juvenile 30

Toad, southern 4 2.94 1.79 0.06 0.36 NA 117.4 286.0 662.9 4.7 Adult 30 

aAll mineral values for this prey species were calculated from equation given in reference.

bNot analyzed. 

Key to minerals:

 Ca - calcium Na - sodium Fe - iron

 P - phosphorus K - potassium Zn - zinc

 Mg - magnesium Cu - copper Mn - manganese
May 29, 2002

14

Table 4. Proximate composition and energy content of whole prey on a dry matter (DM) basis. Values expressed as weighted means

or as raw data when “n” was not stated. Unpublished data. 

Prey species n DM Crude protein Crude fat Ash Gross energy Notes References

 % % % % kcal/g 

MAMMALS

Hamster 2 32.0 51.2 26.0 7.2 5.14a WCS

Mouse, domestic 30 26.1 50.8 34.4 8.0 6.23 Neonatal, <3 g CZS, DZ

Mouse, domestic 57 28.7 59.2 23.8 10.0 5.84 Juvenile, 3-10g DZ, LAZ

Mouse, domestic 7 32.6 56.9 23.5 11.3 5.77 Adult or >10 g CZS, DZ

Rabbit, domestic 1 28.1 63.5 15.3 9.4 5.41 MTZ

Rabbit, domestic 1 33.5 71.2 14.6 11.1 5.22 Eviscerated, incl. hide MTZ

Rabbit, domestic 2 31.3 63.2 20.0 16.0 5.25 a Eviscerated, incl. hide WCS

Rabbit, domestic 6 28.4 61.8 22.6 12.8 5.42 a Meat incl. heart, lungs, kidneys WCS 

Rat 22 31.1 60.4 35.0 10.9 5.67 LAZ, MTZ

Rat 15 23.0 60.3 26.8 11.8 5.67 a Juvenile, 10-50 g WCS

BIRDS

Chicken 11 22.8 67.7 16.5 8.2 5.82 Juvenile LAZ, DZ

Chicken 1 40.5 45.0 51.1 6.2 6.58 Adult MTZ

REPTILES & AMPHIBIANS

Lizard, anolis 4 27.2 66.0 9.0 15.2 4.80 CZS, WCS

Tadpole, bullfrong 1 12.4 NA 16.4 44.0 NAb Young WCS

Tadpole, bullfrog 1 17.6 34.4 31.4 19.9 4.73 a Mature WCS

Tadpole 3 6.9 23.3 21.3 22.7 4.59 Puerto Rican crested toad MTZ 

aCalculated by adding the product of % crude protein x 5.43 kcal/g to the product of % crude fat x 9.11 kcal/g.29

bNot analyzed.

Key to references:

 CZS - Chicago Zoological Society LAZ - Los Angeles Zoo WCS - Wildlife Conservation Society

 DZ - Detroit Zoo MTZ - Metro Toronto Zoo
May 29, 2002

15

Table 5. Vitamin A and E content of whole prey on a dry matter (DM) basis. Values

expressed as weighted means or as raw data when “n” was not stated. Unpublished data. 

Prey species n Vitamin A Vitamin E Notes References

 IU/kg IU/kg 

MAMMALS

Hamster 2 26,666 12.4 WCS

Mouse, domestic 5 17,000 7.0 Neonatal, <3 g CZS

Mouse, domestic 1 130,000 6.0 Adult or >10g CZS

Rabbit, domestic 2 NAa 60.0 Eviscerated carcass WCS

Rabbit, domestic 6 NA 16.2 Meat incl. heart,

 lungs, kidneys WCS

Rat 15 19,265 139.4 Juvenile, 10-50 g WCS

REPTILES AND AMPHIBIANS

Lizard, anolis 4 10,583 11.9 WCS

Tadpole, bullfrog 1 NA 21.6 Young WCS

Tadpole, bullfrog 1 NA 18.0 Mature WCS

Tadpole 3 8,727 62.3 Puerto Rican MTZ

 crested toad 

aNot analyzed.

Key to references:

 CZS - Chicago Zoological Society

 MTZ - Metro Toronto Zoo

 WCS - Wildlife Conservation Society
May 29, 2002

16

Table 6. Mineral content of whole prey on a dry matter (DM) basis. Values expressed as weighted means or as raw data when “n”

was not stated. Unpublished data. 

Prey species n Ca P Mg Na K Cu Fe Zn Mn Notes References

 % % % % % mg/kg mg/kg mg/kg mg/kg 

MAMMALS

Mouse, domestic 30 3.54 1.63 0.12 0.51 1.15 11.0 158.7 77.0 3.6 Neonatal, <3 g CZS, DZ

Mouse, domestic 57 2.96 1.84 0.12 0.49 1.03 12.1 311.9 96.5 9.5 Juvenile, 3-10 g DZ, LAZ

Mouse, domestic 7 2.64 1.91 0.13 0.43 1.02 8.0 251.0 89.4 11.5 Adult or >10g

CZS, DZ

Rabbit, domestic 1 2.35 1.68 0.16 0.54 0.94 16.0 302.0 86.0 16.9 MTZ

Rabbit, domestic 1 1.85 1.36 0.12 0.44 0.87 3.0 100.0 76.0 3.0 Eviscerated MTZ

Rabbit, domestic 3 2.25 1.72 0.19 NAa NA 22.2 127.0 73.0 2.4 Eviscerated WCS

Rabbit, domestic 2 0.64 0.53 0.15 NA NA 41.0 90.4 55.4 1.2 Whole, incl. GIT WCS

Rat 22 3.45 1.91 0.15 0.43 1.05 7.5 194.9 92.1 15.3 LAZ, MTZ

BIRDS

Chicken 11 1.73 1.21 0.08 0.82 0.81 4.0 157.4 93.9 3.3 Juvenile MSU

Chicken 1 1.68 1.30 0.09 0.26 0.53 3.0 40.0 45.0 3.0 Adult MSU

REPTILES & AMPHIBIANS

Lizard, anolis 3 2.30 2.60 0.14 0.50 1.00 353.0 134.0 315.0 3.0 CZS

Tadpole 3 7.67 1.67 0.15 0.73 0.88 46.7 610.2 278.8 58.4 Puerto Rican MTZ

 crested toad 

aNot analyzed.

Key to references:

 CZS - Chicago Zoological Society MSU - Michigan State University

 DZ - Detroit Zoo MTZ - Metro Toronto Zoo

 LAZ - Los Angeles Zoo WCS - Wildlife Conservation Society
May 29, 2002

17

Table 7. Scientific names of whole prey species. 

Common name Genus species 

MAMMALS

Calf, Holstein Bos taurus

Deer, white-tailed Odocoileus virginianus

Guinea pig Cavia porcellus

Hamster Mesocricetus auratus

Hare, snowshoe Lepus americanus

Mouse, domestic Mus domesticus

Mouse, jumping Napaeozapus insignis

Mouse, old-field Peromyscus polionotus

Mouse, white-footed Peromyscus leucopus

Muskrat Ondatra zibethicus

Prairie dog, black-tailed Cynomys ludovicianus

Prairie dog, white-tailed Cynomys leucurus

Rabbit, black-tailed jack Lepus californicus

Rabbit, domestic Oryctolagus cuniculus

Rat Rattus norvegicus

Shrew, short-tail Blarina brevicauda

Squirrel, fox Sciurus niger

Squirrel, gray Sciurus carolinensis

Vole, bank Clethrionomys glareolus

Vole, common Microtus arralis

Vole, meadow Microtus pennsylvanicus

Vole, red-backed Clethrionomys gapperi

BIRDS

Chicken Gallus gallus

Duck, mallard Anas platyrhynchos

Goldcrest Regulus regulus

Pipit, meadow Anthus pratensis

Rook Corvus frugilegus

Quail, Japanese Coturnix coturnix

Tit Parus spp.

REPTILES & AMPHIBIANS

Frog, Cuban tree Osteopilus septentrionalis

Frog, green Rana clamitans

Gecko, fox Hemidactylus garnoti
May 29, 2002

18

Table 7 continued. Scientific names of whole prey species. 

Common name Genus species 

Lizard (19 spp.) Coleonyx variegatus

Callisaurus draconoides

Cophosaurus texanus

Crotaphytus collaris

Gambelia wislizeni

Holbrookia maculata

Phrynosoma cornutum

Phrynosoma modestum

Phrynosoma platyrhinos

Sceloporus clarki

Sceloporus magister

Sceloporus scalaris

Sceloparus undulatus

Sceloporus virgatus

Urosaurus graciosus

Urosaurus ornatus

Uta stansburiana

Cnemidophorus tigris

Xantusia vigilis

Lizard, anolis Anolis carolinensis

Lizard, bearded dragon Pogona vitteceps

Snake (4 spp.) Chilomeniscus cinctus

Contia tenuis

Salvadora hexalepus

Sonora semiannulata

Tadpole, bullfrog Rana catesbeinana

Tadpole, Puerto Rican crested toad Peltophryne lemur

Toad, southern Bufo terrestris
May 29, 2002

19

Appendix 1. Partial listing of whole vertebrate prey commercial suppliers (USA). 

Name Address City State Zip Telephone Fax Website/email 

Bayou Rodents 9008 Highway 182 W., Centerville LA 70522 800-722-6102 337-836-5346 bayourodents@cox-internet.com

 P.O.Box 238

BGC Exotic Pet Foods 7715 Robe Menzel Road Granite Falls WA 98252 877-691-3599 360-691-6510 www.bgcpetfoods.com "baby chicks only, no rodents"

Big Cheese Rodents Rt. 1 Box 59A Iredell TX 76649 800-887-0921 254-364-2874 www.bigcheeserodents.com

Bush Herpetological P.O. Box 539 Neodesha KS 66757 800-451-6178 www.bushherp.com

Cajun Mice P.O. Box 238 Centerville LA 70522 888-919-4327 337-836-5346 www.cajunmice.com

CAP Company Surplus 767 Watson Road Mooresville IN 46158 317-479-1738 317-831-9040

Carolina Mouse Farm P.O. Box 382 Salem SC 29676 864-944-6192 www.mousefarm.com

Central Coast Reptiles P.O. Box 5255 San Luis Obispo CA 93401 805-546-2620 www.centralcoastreptiles.com

Colorado Rocky 1156 3950-Road Paonia CO 81428 800-367-3440 call first "not yet, but coming soon"

 Mountain Rodents

Critters, Ltd. 845-626-5746 www.critterslimited.com

D&H Pet Farms, Inc. 3103 S. Sapp Road Plant City FL 33567 813-752-0257 813-759-6575

eHerp.com R.R. 1 Box 166 Thayer KS 66776 www.eHerp.com

Essex Pets Route 1, Box 171 Blum TX 76627 800-336-6423 254-582-7306 www.essexpets.com

Hoosier Mouse 2690 Observatory Road Martinsville IN 46151 317-831-1219

 Supply, Inc.

Kevin and Kelli Bryant P.O. Box 4424 Evansville IN 47724 812-867-7598 812-867-6058 www.reptilesandrodents.com

LA Mouse Farms P.O. Box 12841 New Iberia LA 70562 877-438-7287 337-364-9179

LAM Distributing Co. P.O. Box 407 Rusk TX 75785 352-495-9024

Lonesome Dove Rabbitry 910 Yew St. Centralia WA 98521 360-736-2560

Mice on Ice (Zoological 2000 SE 43rd Terrace Gainesville FL 32641 800-438-7287 352-377-2244 www.miceonice.com

 Pet Food, Inc.)

Mice Unlimited P.O Box 71142 Shasta Lake City CA 96079 800-642-3496 800-642-3496 www.miceunlimited.com

Midwest Reptile and P.O. Box 1173 Greenwood IN 46142 317-882-8088 317-881-1856 www.midwestreptile.com

 Frozen Rodents

Mighty Mice 3172 N. Rainbow Las Vegas NV 89108 708-658-0921

 Blvd. 319

Mouse House 28325 S. Cole Grade Valley Center CA 92082 619-751-9929

 Rd. Ste. A

Mouse Trap P.O. Box 253 Colton OR 97017 803-824-MICE

MZ Enterprises 10610 Emory Road Luttrell TN 37779 615-687-0757

Northwest Gamebirds 228812 E. Game Farm Rd.Kennewick WA 99337 509-586-0150

Oak Run Rodent Co. P.O. Box 341 Palo Cedro CA 96073 530-472-3294 530-472-3294

P.S. Rodents, Mice 28120 Mary Place Murrieta CA 92563 909-698-6835
May 29, 2002

20

Appendix 1. Partial listing of whole vertebrate prey commercial suppliers (USA). 

Name Address City State Zip Telephone Fax Website/email 

Perfect Pets Inc. 23180 Sherwood Belleville MI 48111 800-366-8794 734-461-2858 FrozenRodents@aol.com

Pied Piper Rt. 2 Box 223-AA Speedwell TN 37870 615-869-5524

Quality Rodents P.O. Box 1942 Appleton WI 54911 920-738-7312 920-810-8920 www.qualityrodents.com

Rat Alley 800-469-5450 760-949-3372 ratalley@aol.com

Rat Ranch 2010 S. Forbes Road Plant City FL 33567 813-754-6258

Rodent Empire 5050 Laguna Blvd. Elk Grove CA 95750 916-394-1756

 112-425

Rodents on Ice 540-989-4033

Snake Snacks P.O. Box 12026 New Iberia LA 70562 877-468-7287 877-468-7287 www.snakesnacks.com

SOS Rodent Express 54 Club Road Oley PA 19547 610-689-4770

Southwest Rodents 13911 S. Old Sonita Hwy Vail AZ 85641 520-762-5023

Suwannee Mouse Farm HC 1 Box 67 Old Town FL 32680 352-542-2247 swaneemice@webtv.net

The Gourmet Rodent 6115 SW 137th Avenue Archer FL 32618 352-495-9024 352-495-9781 Grmtrodent@aol.com

The Mouse Factory P.O. Box 85 Alpine TX 79831 800-720-0076 www.themousefactory.com

Twin Oaks Livestock 1500 East Piney Road Dickson TN 37055 615-446-8877 615-446-8877

Vanco 6300 Lange Road Howell MI 48843 517-546-8612

Varmints 30816 144th Ave. E. Graham WA 98338 360-879-5580

Wild Things 12102 N. Nebraska Ave. Tampa FL 813-978-8885 813-978-8885 www.globalwildthings.com

Youngs Mouseary 219 Sand Pond Road Marlow NH 03456 603-446-2316

Map and State Directory can be found at: http://HerpKeepers.com/feeders/suppliers.html

For more listings see also: www.sonic.net/~melissk/preysrcs.html