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TestDiet FAQ

The fundamental purposes of purified diets are full knowledge of all ingredients, complete open formulas, ease of modification, and repeatable consistency, resulting in accurate, reliable data. Purified open formulas diets (AIN, Van Heek, for example) specify the exact description and the exact amount of each ingredient, including all minerals and vitamins. Each nutrient is derived from a distinct, refined ingredient. Ingredients are obtained from reliable, consistent, traceable and proven suppliers. In grain-based diets, each nutrient has multiple sources; therefore, to modify a grain-based diet, many ingredients must be adjusted. For modified LabDiet® formulas, we strongly suggest you contact before you proceed with any supplier; only our LabDiet® and TestDiet® nutritionists can accurately modify a LabDiet
Often we can meet your research needs by adding nutritional components to standard grain-based animal food (i.e., our LabDiet® products). This process is used often for adding fats, oils, cholesterol, and can be used to add any nutrient(s), such as protein, minerals, vitamins, carbohydrate, and fiber. When required by your research, we can also add medications and test compounds to any diet, including standard LabDiet® products, and custom diets, both grain-based or purified. Alternatively, we can produce custom-formulated grain-based LabDiet® products for you from scratch, using standard multi-nutrient ingredients normally used in such products, or substituting nutrient-specific ingredients (such as milk casein as a protein source). This is particularly useful when you need a diet comparable to one of our standard LabDiet®products, but with certain components deleted from the formula (e.g., a diet with no added Vitamin A, or no soy protein). The standard LabDiet® product is typically used as a control diet in this situation.
Adding test compounds to standard or custom grain-based diets or purified diets is an effective, accurate, and convenient means of dosing your animals for research purposes. With precision and consistency, we can homogeneously blend in virtually any compound, medication, or nutrient and produce the diet in any form: pellets, meal, or tablets; many can be made into a powder form for liquid diets. All test compounds need to be approved by the TestDiet® plant manager prior to accepting them into our facility. We never compromise the integrity of our products; we never endanger the validity and accuracy of your research, nor the safety and health of you or our staff. Therefore, we do not handle any toxins, carcinogens, mutagens, radioactive substances, controlled dangerous substances (CDS), or live organisms (viruses, bacteria, etc.). Thus, you are assured that no dangerous or deleterious cross-contamination will occur in our manufacturing process.
Our team of animal nutrition professionals can custom-formulate purified or grain-based research diets for virtually all animal species, including rats, mice, guinea pigs, hamsters, rabbits, chinchillas, ferrets, felines, canines, primates, swine, poultry, reptiles, fish, aquatic mammals, zoo animals, exotic birds, etc.
LabDiet® products have been the baseline of nutrition for the biomedical research community for several decades. Whenever nutritional or physical requirements cannot be met using a standard LabDiet® product, our nutritionists will formulate and produce custom research TestDiet® animal diets to meet your individual study demands.
We feel there are many reasons including the following: Quality and Food Safety LabDiet® and TestDiet® products have been the worldwide leader in laboratory animal nutrition for decades, we know your needs and will deliver on your request. Our company, Purina Animal Nutrition has a deep knowledge of ingredients, nutrients and animal feed formulations. We are a food and feed company with a dedicated focus on product safety. Our facilities where our TestDiet® products are manufactured produce custom grain-based and purified diets for animal research in academic, government, and pharmaceutical laboratories worldwide. We operate the cleanest, most efficient, most comprehensive GMP-compliant and FSSC 22000 Certified laboratory animal diet production facility anywhere. Dependable Service With facilities in the USA and UK, we are uniquely equipped to provide professional service of the highest caliber where ever you are located – we ship TestDiet® products around the world. Our team of dedicated small animal Ph.D. nutritionists will interact with you to formulate the best diet for your research needs and our proven Certified LabDiet®Dealer network will deliver your diet while providing unmatched customer service. Your Certified LabDiet® Dealer can assure that your diets are delivered in one consolidated shipment if requested, or can work with you to stock your products in their local warehouse to provide you “just-in-time” delivery—as you choose. Reliability & Value Added We are a feed company, first and foremost. Whether your research costs only hundreds of dollars or involves multi-year research costing in the tens of millions of dollars, to you it is priceless. We have the dedicated resources, proven history, stability, and century-long reputation of animal feeding to protect your interests. Why trust such a vital part of your research—your animals’ diets—to anyone else? Through our TestDiet® products, we are committed to providing the highest quality lab animal research diets possible. What we are committed to offer you is impeccable quality, exemplary service, and absolute reliability at a fair and reasonable price.
Whether you produce your own diets or use a diet from another company, we can duplicate it and deliver it to you in whatever form you desire—pellet, powder, liquid, or tablet. Purified diets, by their very nature, may be exactly duplicated since “repeatability” is one of the defining hallmarks of purified diets. Any manufacturer of a purified diet must provide you with a complete open formula so that you or anyone else can repeat that precise diet next week, next, month, or next year. For grain-based diets, precise formulas are usually not available, but a list of ingredients and nutritional specifications are. Consequently, we will produce comparable grain-based diets using similar ingredients and resulting in approximately equivalent nutritional content.
We need to know some details about your research: the general objective of the research, the animal species and strain, the purpose of the diet, ingredients and nutrients of particular interest, any existing formula(s) you want duplicated or modified, any journal articles related to your specific study. Be as specific as possible, for example, avoiding subjective descriptions such as “low-fat” or “high-cholesterol;” the definition of such terms vary significantly from researcher to researcher.
Yes we can – in our Verified Rodent Diets. Introduced initially in 1995, our line of Verified Diets provides you a known level of desired total isoflavones in each batch. Alternatively, Purified diets are inherently free of phytoestrogens (if soy is not used as the protein source). Our nutritionists that formulate LabDiet® & TestDiet® diets produce the Advanced Protocol Verified Rodent Diet products. These are a line of grain-based diets with controlled, measured, and verifiable levels of phytoestrogens at 150 ppm, or 50, ppm, or even less than 10 ppm.
Generally, researchers will cite specific TestDiet® formulas when reporting their research. This assists readers in understanding fully the nutritional aspects of the studies, and assists researchers in repeating and modifying methods when conducting their own studies. (It is important for researchers to report the 4-digit alphanumerical formula number, not the product number that is different for each form of the diet, e.g.,1/2″ pellet, 3/8″ pellet, meal, etc.) When authors cite these diet formulas, we can provide exactly the same formula to you, and we can produce “variations on the theme” as your specific research may require. When authors do not cite the specific diet formula, they will usually provide formula information on your request. Without a citation in an article or permission of the author, we cannot provide you any more information about a diet than appears in the article; however, we can provide diets that meet the same diet parameters disclosed in the article.
Casein is a protein source derived from cow’s milk. “Vitamin- tested casein” is alcohol-extracted casein prepared from regular casein, and typically has 90-91% protein (%N x 6.38), 0.1% fat, and 4-6% moisture. Casein that is not vitamin-tested and used in research formulas may introduce unknown and random amounts of various vitamins into each batch of diet without being recognized or reported. The protein content of alternative casein can also fluctuate significantly. Whoever manufactures your purified diets should assure you that they are using pure ingredients of known, verifiable, consistent composition to the greatest extent practicable. Consistent with the value of your research, TestDiet® formulas use only precise vitamin-tested milk casein in the purified diets.
For purified ingredient diets, we always provide you a complete open formula, listing the exact description and precise amount of each ingredient, including all minerals and vitamins, and a comprehensive calculated nutritional content. For modified grain-based LabDiet® formulas, we provide a list of all ingredients and a complete calculated nutritional content.
For decades, we have supported the research of leading pharmaceutical companies, government laboratories, and academia worldwide: they continue to trust us to respect absolute confidentiality. We never reveal information to anyone about the diets you purchase or the experiments you are conducting without your explicit prior approval or by your own publication of research data. When you do publish your research, we encourage you to note precisely the TestDiet® formulas you have used to assist others in repeating and modifying your methods in their own studies.
We can formulate diets with a various types and amounts of fats – animal and vegetable fats solid and liquid fats. We can produce diets with as much as 60% kcal from fat (35% fat by weight). We will formulate and produce custom diets to your exact specifications. We manufacture several standard “DIO” (Diet-Induced-Obesity) diets used extensively by researchers worldwide. One group of diets is commonly known as the Van Heek series or diets 58Y2, 58V8 & 58Y1.
Almost all TestDiet® products can be made in any form: powder (meal), pellets, tablets, or liquid. We produce pellets with as much as 60%kcal from fat (≈35% fat by weight); higher fats levels can be made into a convenient “cookie dough” consistency. All of our diets are first prepared as a meal mixture of all dry and wet ingredients. Depending upon the needs of your research, we can supply diets in this meal form, or process them into a pellet, a tablet or as a suspended powder for mixing as a liquid diet with water or ethanol. Our standard pressed pellet is 1/2″ in diameter by 3/4″ to 1-1/4″ in length; smaller diameters of 3/8″ or 3/16″ are available for ferrets, guinea pigs, swine, and rabbits. Our suspended powder form for liquid diets can be used in many types of research. They are convenient to use, mix easily, and, once mixed with water or ethanol, can be stored under refrigeration for several days. Diets can be compressed into tablets of precise weights and sizes for a variety of purposes, most notably used to reward and reinforce behavior through pellet dispensers (Skinner boxes) and to provide enrichment as treats. This “dosage” form is available in standard purified and grain-based formulas, and in formulas custom-designed for your specific research.
TestDiet® products are custom-mixed fresh to fill each order. Typically, non-irradiated products are available within 7-10 business days after you place your order, we will plan to have the diet available for your Certified LabDiet® Dealer to collect and arrange delivery to you. If you need your diet irradiated, generally you will need to add up to an extra 7-10 days, although we strive to reduce that extra time whenever possible. When your need is urgent we will work with you, rush service is usually available with only a reasonable additional charge if overtime labor is necessary.
Purified ingredient diets are perishable; they do not contain any preservatives unless clearly stated in the formula. They should be stored in a cool, dry place. Refrigeration at 4°C (40°F) or lower with <50% relative humidity is recommended; generally, diets can be stored this way for up to six months. Most diets can be preserved even longer by freezing, sometimes for up to a year; however, use of diets beyond six months will be subject to the protocols of your lab. For shelf-life of grain-based LabDiet® products see
Standard packaging for custom diets is 10 kg packed within a 3-mil poly bag for non-irradiated diets and 10 kg in an 8-mil poly, heat-sealed, bag for irradiated diets. Our bags are specifically formulated and created to contain no estrogenic activity (EA). Bagged diets are then packed in a double-walled corrugated box. High fat diets are packed in an insulated Styrofoam container within a double-walled corrugated box. Special packaging options are available upon request; however, EA free bags may not be available for those special options.
Research facilities are increasingly specifying gamma-irradiation as the economical and practical alternative to autoclaving. Many purified diets cannot be autoclaved without damaging the diet. At your request, all our TestDiet®products can be sterilized by gamma-irradiation at a nominal additional cost, usually only $1/kg with no minimum quantity. Irradiation normally takes up to 10 additional business days; expedited service is sometimes available at an extra cost.
We are committed to providing the highest quality lab animal research diets possible. Often we can provide exactly the same formulae currently available elsewhere. The incomparable value we offer you is impeccable quality, exemplary service, and absolute reliability at a fair and reasonable price. We manufacturer custom diets fresh – only as needed by researchers; therefore, we quote prices on an order-by-order basis, depending upon quantity, ingredients, and the complexity of the formulation and production method. Setting up a standing order for regular weekly or monthly deliveries of the same diets, may sometimes allow us to extend more favorable lower quantity pricing, depending upon the diet and other logistical considerations of the Certified LabDiet® Dealer. Please contact your Certified LabDiet® Dealer or TestDiet® Customer Service at for price quotes.
In most areas of the United States, Canada and the rest of the world – our network of Certified LabDiet® Dealers will provide personal attention and service for your order, delivering products to you as and when you want at reasonable rates. You receive the world-class service and attention of local professional dealers. Be sure and ask your Certified LabDiet® Dealer for options of delivery and local storage, which can often very efficient for large orders. TestDiet® Products are available around the world For formulating new diets, nutritional consultation, or for TestDiet® product re-orders, contact us directly at We strive to provide rapid service around the globe. Via airfreight, you can receive your diets usually within five days transit time or less, often overnight. In many parts of the world, we have Certified LabDiet®Dealers or authorized representatives to provide professional local attention to your research requirements. Transit Time and Product Stability Our TestDiet® products, whether purified or grain-based, are routinely shipped by various methods. Depending upon where you are located and what method of shipment you choose (and how much you want to pay for freight), transit time can be as short as one day or as long as two-three weeks. With rare exceptions, these products are perfectly stable for those transit times even though upon arrival we recommend that they be stored in a cool, dry place; refrigerated if available. For some very-high-fat diets, especially when shipped during the hot summer months, we will recommend “second-day” or “overnight” shipping, not so much to prevent spoiling as to preserve the pellet shape of the diet which may begin to crumble with extended exposure to elevated ambient temperature.