Abstract

Raw meat is highly perishable and requires safe and sanitary preparation, handling and storage. Wild cats may tolerate concentrations of microbes in prey that would be pathologic to captive felids. Just as zoo animal nutritionists have the knowledge to formulate many types of animal feeds and arrange for their manufacture, so we have the ability to develop safer, raw meat-based diets according to a specific formula. We can also develop standards for more sanitary methods of manufacture, handling and storage. Meat-based canned (heat processed) and baked diets have been tested in zoo felids (S. Crissey and M. Edwards, personal communications), but so far stool condition and acceptability are poor. However, Crissey et al. demonstrated that sand cats (Felis margarita) with a body mass of about 2 kg, consumed an extruded diet with good digestibility and no deleterious effect on stool condition.¹

Dry, extruded diets are also being tested in large cats (M. Edwards, personal communication). However, many species of larger cats do not seem to tolerate more than 50% of dry matter intake as dry food, as evidenced by food refusals or poor stool condition. Due to recent reports of quality and consistency problems with some frozen carnivore diets in 1997 and 1998, we began to consider a new formulation for raw meat-based diets. In response to a number of requests, ingredient and nutrient specifications for both horsemeat- and beef-based raw diets have been developed (Table 1). In addition, microbiologic guidelines have also been established with the assistance of a professional food safety microbiologist (Table 2).

Table 1. Frozen horsemeat-based carnivore diet ingredient and nutrient specifications (11/14/98)

Application. This product is a frozen, fresh meat diet for use in the feeding of captive carnivores. It may be used as the sole diet for felids. In addition, provision of knuckle bones to chew on, two or more times per week, may aid in promoting oral health. With further testing, it is probable that this diet will also be suitable for carnivorous birds, reptiles and other carnivorous mammals.

Ingredients. Horsemeat or horsemeat trimmings, Solka Floc (wood cellulose), calcium phosphate tribasic, sodium chloride, carnivore trace element premix, carnivore vitamin premix, choline chloride, taurine, stabilized L-ascorbyl-2-polyphosphate.

Ingredient and Product Standards. All meat and meat products shall originate from animals slaughtered in plants subject to the Meat and Poultry Inspection Operations regulations of the USDA Food Safety and Inspection Service (FSIS), or under a system of inspection approved by FSIS. All bones, cartilage, heavy connective tissue, lymph glands, and central nervous system tissue shall be removed. Likewise, meat and meat products that originate from animals or carcasses designated as 3-D or 4-D shall not be used. Other (non-meat) ingredients shall conform to standards as defined by the Association of American Feed Control Officials (AAFCO).
The product shall be routinely monitored for specific microbial populations. The diet must test negative for the presence of Salmonella and Listeria, and within specified tolerance limits for total coliforms and E. coli.

Nutrient Concentrations. The product has been formulated to meet or exceed the minimum NRC nutrient concentrations required in purified diets for the growing domestic kitten and AAFCO nutrient profiles for growth and reproduction of cats fed practical diets. All values, except moisture, are expressed on a dry matter basis.

Table 2. Microbiologic guidelines for raw meat-based diets

Unlike most products marketed in North America, the specifications call for horse or beef muscle tissue, a small amount of a carbohydrate “filler” and specific vitamins and minerals. Nutritionists at the Metro Toronto Zoo (MTZ) developed similar specifications some time ago. Milliken Meats in Toronto, Ontario, Canada, manufactures MTZ carnivore diets according to their specifications. These products are well accepted by MTZ carnivores. At present, our specifications have been given to three potential manufacturers in the United States. Two of these companies are making test batches of both horse- and beef-based diets. These have been fed to over 15 species of felids and have been well received by both keepers and captive felids. Acceptable manufacturing plants are required to process diets under conditions acceptable to U.S. Department of Agriculture (USDA) or to Agriculture Canada (AC) using only muscle meat that is fit for human consumption. No contaminated (3-D) meat (disabled, diseased and down) may be used. Processors must also use a metal detector that will detect metal that is 2 mm thick or greater. We will require any manufacturer to provide Safe Sanitary Operating Procedures (SSOPs), Material Safety Data Sheets (MSDS) and their HACCP (Hazard Analysis Critical Control Points) program.

The quantitative nutrient requirements of nondomestic cats are not known. However, we used the established requirements of the domestic cat as guidelines in formulating diets for zoo cats.² Other considerations in feeding captive cats include attention to the integrity of teeth and gums. Oral heath can be improved by feeding bones with meat attached at least twice per week, or by feeding whole vertebrate prey. Such feed items will also extend the time spent feeding, which is desirable from a behavioral standpoint.

We believe that zoo animal nutritionists have an obligation to ensure that not only nutritional needs are met, but that sanitation and food safety are equally important, particularly for highly perishable rations.

Literature Cited

1.  Crissey, S.D., J.A. Swanson, B.A. Lintzenich, B.A. Brewer, and K.A. Slifka. 1997. Use of a raw meat-based diet or a dry kibble diet for sand cats (Felis margarita). J. Anim. Sci. 75:2154–2160.

2.  National Research Council. 1986. Nutrient Requirements of Cats. National Academy Press, Washington, DC.