- What is a Standard
diet?
- What are Global
diets?
- What are Traditional
diets?
- What are Fixed Formula
diets?
- What is a certified
diet?
- How does Harlan Laboratories
ensure the high quality and consistency of Teklad Global and
Traditional standard diets?
- What is the shelf life of a
standard diet?
- Does Harlan
Laboratories offer irradiated standard diet and bedding
products?
- How do autoclavable diets
differ from non-autoclavable diets?
- What are
phytoestrogens?
- Does Harlan Laboratories
offer Teklad diets that are phytoestrogen free?
- What is a custom research
diet?
- What is a purified
diet?
- What is the difference
between AIN-76A, AIN-93G, and AIN-93M?
- How does Harlan
Laboratories ensure the high quality and consistency of Teklad
custom research diets?
- Can Harlan
Laboratories add test compounds to diets?
- Why should I contact a
Nutritionist?
- What information will help in
the design of a custom diet formula?
- What is the minimum order
quantity?
- How are custom research diets
priced, and how can I place an order?
- How are diets
packaged?
- How long after I place my
order will I receive my diet?
- What is the shelf life of a
custom research diet?
- Can custom research diets be
irradiated?
- How can I order a diet
supplied to someone by Harlan Laboratories, and subsequently noted
in a research article?
- Can Harlan Laboratories
manufacture a diet made by another company?
- Can any custom diet formula
be made in pellet form?
- What is "Vitamin-free" test
casein?
- Does Harlan Laboratories sell
diet ingredients?
- How do I cite a Teklad Diet
in a publication?
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1. What is a
standard diet?
A more complete name would be Standard Natural-Ingredient Diets.
These diets are manufactured in large quantities (at least 2 tons)
and stocked at one or more Harlan Teklad distribution centers.
Standard natural ingredient diets are readily available and can
generally be delivered within a few days after an order is placed.
These diets primarily contain grains (corn, wheat), legumes
(soybean meal) and to a lesser extent ingredients such as fish
meal, and meat and bone meal.
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2. What are Global Diets?
Using standardized fixed formulas and ingredients purchased
under the same stringent specifications in the Unites States and
Europe, Harlan Laboratories' unique Teklad Global Diets
Program provides nutritional consistency to national and
multinational companies for their worldwide research, maximizing
global study uniformity. Global Diets have the same product
names in all countries. The Global Rodent diets have lower
protein levels than most traditional diets and are formulated free
of alfalfa with zero or modest amounts of soybean meal, thus
minimizing the presence of natural phytoestrogens.
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3. What are Traditional
diets?
Harlan Laboratories offers a variety of Traditional Teklad diets
for the common laboratory animal species. These fixed formula
diets are made from high quality ingredients. While traditional
diets will supply the known nutrient needs of laboratory animals,
we recommend that researchers consider the use of a diet from our
Global Diet line. The traditional rodent diets were formulated
decades ago based on understanding of rodent nutrition,
ingredients, and diet manufacturing at the time. There was
limited appreciation of the effects of non-nutrients, such as
phytoestrogens, on experimental results. Alfalfa meal and soybean
meal are the major sources of phytoestrogens in laboratory animal
diets. These ingredients, particularly soybean meal, are found in
most traditional rodent diets.
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4. What are fixed formula
diets?
Fixed formula diets are diets that are manufactured in
accordance with a formula that remains unchanged from one
production to the next. In conjunction with strict quality
standards for raw materials, this approach ensures quality and
consistency by minimizing nutrient variability and the variability
of other phytochemicals in the diet which might affect a research
study.
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5. What is a certified
diet?
Certified diets are diets that have been tested for a standard
panel of environmental contaminants that are known to be capable of
interfering with a study. These diets help ensure that a study
complies with the FDA’s Good Laboratory Practices regulations
requiring periodic feed analysis. A Harlan Laboratories
certificate of analysis signed by a nutritionist is made available
to the customer. For more information see
Certified Diets.
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6. How does Harlan Laboratories
ensure the high quality and consistency of Teklad Global and
Traditional standard diets?
Our #1 goal is to provide quality and consistent products to our
customers. This begins with ensuring that raw materials of only the
highest consistency and quality are obtained. Raw materials are
only obtained from approved suppliers who agree to meet our quality
standards. Suppliers are audited on a regular basis and their
products are tested for quality before being accepted into our
facilities. Fixed formulas and established manufacturing procedures
are in place for each product which ensure that the product is
manufactured consistently with each production. In-process and
final product testing is completed prior to distribution of the
product to a customer. Harlan Laboratories utilizes its own network
of company owned and operated distribution centers throughout the
US and Canada rather than use outside distributors.
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7. What is the shelf life of
standard diets?
There is no definitive point where one is able to predict when a
specific diet will spoil or become deficient in one or more
nutrients. However, based on various studies and longstanding
standard industry practice, we have some general recommended
guidelines. Storage of all of our standard natural ingredient diets
at or below 70 degrees Fahrenheit with humidity at or below 50%
will maintain the nutritional quality for 6 months (shelf-life).
Increases in temperature and humidity above these values will
hasten the degradation of various nutrients and increase the
probability that the diet may not meet the nutritional requirements
of the target animal. In addition, diets should be stored in a
clean area free of pests with no exposure to direct light. Given
these conditions all of our standard natural ingredient diets for
laboratory animals can be fed through 6 months from the date of
manufacture. Standard natural ingredient diets that are vacuum
packaged and irradiated may be fed through 9 months after the date
of manufacture.
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8. Does Harlan Laboratories offer
irradiated standard diets and bedding products?
Harlan Laboratories offers
irradiated diets, bedding, and enrichment items. Irradiation
reduces the bioburden (number of organisms) contained by a product
by exposing the product to gamma ionizing radiation from cobalt-60.
Organisms exposed to gamma irradiation are damaged at the molecular
level often with lethal effects. The net result is a decrease in
the amount of viable microorganisms present in the product. Harlan
irradiates all Teklad products at a minimum dose of 2.0 Mrad
(20kGy) and a maximum of 5.0 Mrad (50 kGy).
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9. How do autoclavable diets differ
from non-autoclavable diets?
Autoclaving destroys vitamins and amino acids that are
supplemented in the diet. To compensate for this destruction,
autoclavable diets contain an additional supplement of vitamins and
supplemental amino acids. Autoclavable diets are packaged in
perforated bags which allow steam from the autoclave to penetrate
throughout the diet when the diet is autoclaved inside the
bag.
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10. What are
phytoestrogens?
Phytoestrogens are phytochemicals naturally produced by plants
which interact with endogenous estrogens. They have some similarity
in molecular structure compared to endogenous estrogens and bind to
some extent with estrogen receptors. Phytoestrogens have been shown
to affect mammalian physiology including cancer growth,
atherosclerosis, calcium-phosphorus metabolism, and behavior. This
is of concern to researchers because standard natural ingredient
diets are often composed of ingredients which contain significant
quantities of phytoestrogens. Soybean meal is an ingredient common
to standard natural ingredient diets which contains a class of
phytoestrogens called isoflavones. The two primary isoflavones are
genistein and daidzein. Alfalfa meal is a second ingredient common
to standard natural ingredient diets. It contains the phytoestrogen
coumestrol.
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11. Does Harlan Laboratories offer
Teklad diets that are phytoestrogen free?
The term “free” implies the total and complete absence of
phytoestrogens. This would exclude any diet composed of natural
ingredients. The only type of diet that would be completely free of
phytoestrogens would be soy protein-free purified diet (see custom
research diets section). However, Harlan Laboratories offers four
Teklad Global diets that exclude ingredients such as alfalfa meal
and soybean meal which are known to contain large amounts of
phytoestrogens. The Teklad Global Rodent Diets 2014, 2016, 2019,
and 2020X while not completely “free” are best described as minimal
phytoestrogen diets. Quarterly testing of these diets for
isoflavones (phytoestrogens from soybean) typically reveals levels
ranging from less than detectable to 20 ppm. For some perspective,
most traditional rodent diets contain from 200 to 500 ppm
isoflavones. Phytoestrogen minimal diets such as 2014, 2016, 2019,
and 2020X are generally acceptable for studies where phytoestrogens
are of concern.
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12. What is a custom research
diet?
Custom research diets are made in small quantities and are
generally not stocked. These diets are typically formulated
for a specific type of research objective. These diets can consist
of refined ingredients (purified diets), natural ingredients (grain
and other ingredients found in standard diets), or utilize a
standard diet as a base to which other ingredients are added. Any
of these diet types can serve as the basis to add a
customer-supplied ingredient (test article, pharmaceutical, food
extract, etc). We have approximately 20,000 diets in our
database, so the formula you require may already have been created.
We also utilize this database as a resource when formulating new
diets. We will be pleased to provide you a complete formula sheet,
containing the ingredients and inclusion rate, macronutrient
values, key features, and planning and ordering
information.
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13. What is a purified
diet?
A purified diet uses refined ingredients such as casein,
sucrose, cornstarch, and cellulose. These human food grade
ingredients have relatively simple chemical compositions
(predominantly one nutrient classification) and this feature is
important for manipulating individual nutrients for research
purposes. Additionally, most refined ingredients contain very
limited levels of non-nutrients that could have biological
activity. This is in contrast to the natural ingredients (corn,
wheat, soybean meal, etc.) used in standard diets, which have
relatively complex chemical compositions as well as various
phytochemicals that may or may not be physiologically
relevant. Refined ingredients are obtained from reliable
suppliers of human grade products, and we consistently obtain
ingredients from the same vendors, year after year. Additionally,
the major protein ingredients are assayed for a specific panel of
nutrients to ensure minimal variation. Thus, purified diets will be
repeatable and can easily be modified. Examples of common purified
diets include AIN-76A (CA.170481), AIN-93G (TD.94045), and AIN-93M
(TD.94048).
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14. What is the difference between
AIN-76A, AIN-93G, and AIN-93M?
The American Society for Nutrition (ASN) (formerly American
Institute of Nutrition, AIN) has promoted the use of nutritionally
adequate purified diets for rodents, because many researchers may
not be aware of potential nutritional variables. The AIN-76 formula
was published in 1977, and became AIN-76A with minor revision
(increased Vitamin K) in 1980. The diet has been used extensively,
and there were several suggestions about improvements. This
resulted in the publication of two formulas in 1993, AIN-93G (for
growth, reproduction, and lactation) and AIN-93M (for maintenance).
The article J. Nutr. 123: 1939-1951 (1993) discusses the rationale
for the several revisions. Some of the changes include soybean oil
rather than corn oil, the addition of other carbohydrate sources
and lower sucrose, decreased phosphorus, cystine in place of
methionine, inclusion of several trace mineral elements, and a few
vitamin adjustments. The maintenance diet has less protein and
fat.
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15. How does Harlan Laboratories
ensure the high quality and consistency of Teklad custom research
diets?
Each formula is given a unique identification number and retains
that identity among the thousands of formulas in our files. This
assures the same formula will be used even years later. Upon
production, a six-digit lot number is assigned that allows for
traceability through all phases of diet production. These detailed
production records are kept for every item produced.
Quality-control samples are retained for nine months. Each lot of
the major protein ingredients is analyzed for a number of nutrients
to verify uniformity from lot to lot. Care is taken to retain
reputable vendors for these refined ingredients.
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16. Can Harlan Laboratories
add test compounds to diets?
Yes, we can help you in adding a test compound or ingredient to a
diet. This is often a convenient approach to dosing research
animals. When adding a compound to a diet, there are some important
safety and stability considerations. Please see customer supplied
ingredients for more specific information.
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17. Why should I contact a
Nutritionist?
A phone call or an email exchange with one of our staff will
augment the information that you gather from the web site or
published literature, and you are more likely to receive a diet
that best meets your particular needs. We are careful to maintain
confidentiality, and will sign formal agreements if necessary.
Please contact us for consultation regarding your specific diet
needs.
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18. What information will help in
the design of a custom diet formula?
Advise us why the diet is needed, and for what animal species.
Discuss the nutrients or ingredients of interest in as much detail
as possible. Please avoid subjective descriptions such as "low,
normal, and high" because these terms have different meanings to
various researchers. Provide us with a copy of any existing formula
to be duplicated or modified, and any journal article(s) upon which
your research may be based. Let us know if the diet must be
irradiated.
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19. What is the minimum order
quantity?
Our minimum order (for diets) is 3 kg. This is particularly
convenient when feeding small numbers of mice, especially diet that
has contains your test compound. The minimum quantity for vitamin
and mineral mixes is 500 g.
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20. How are custom research diets
priced, and how can I place an order?
Prices are dependent on formula details, ingredient composition,
order quantity, and form (pellet or powder). If you know the
product code, contact customer service at 800•483•5523,
608•277•2066 (fax) or tekladinfo@harlan.com. If you are
unsure of the product code, have a new request, or require other
technical information, contact a Nutritionist at 800•483•5523 or
askanutritionist@harlan.com.
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21. How are diets custom diets
packaged?
Standard packaging includes two small size boxes (9 x 9 x 11
inches and 10 x 10 x 15 inches) that will fit up to 10 kg, and a
larger box (13 x 13 x 20 inches) with inset handles that holds up
to 20 kg. These durable boxes can withstand a variety of shipping
conditions. Every container also includes a 3-mil poly liner to
keep your research diet as fresh as possible. Vacuum packaging and
specific quantity packaging are also available at additional cost.
Irradiated diets are double-bagged. Contact us at
tekladinfo@harlan.com for more information.
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22. How long after I place my
order will I receive my custom diet?
Diets are custom made to fill each order. They are not
inventoried. The typical lead-time between order and shipment
is 10 business days, unless irradiation is required (add 10
business days). We can most often accommodate your rush production
needs, for an additional fee. Contact us at tekladinfo@harlan.com
for more details. Transit time depends on the type of delivery
method used (regular ground, overnight, etc.). Weight and delivery
method affect shipping costs, which are typically prepaid and added
to the invoice. The exception to this is TD.88137, which for
orders of 25 kg or less, is usually available within a
week.
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23. What is the shelf life of
custom research diets?
There is no definitive point where one is able to predict when a
specific diet will spoil or become deficient in one or more
nutrients. Custom research diets are perishable and should be
refrigerated at 4°C (40°F) or lower (see Fullerton, et.al. J Nutr.
112:567-573, 1982). As a general guideline, diets can be stored
this way for up to six months. It’s likely that many diets can be
preserved even longer by freezing, perhaps up to a year; however,
use of diets beyond the recommended use date will be subject to the
protocols of your institution.
Custom research diets vary significantly in their formulation.
There may be certain features of a diet that merit a shorter
shelf-life. To learn more about storage and use
recommendations, and to help you asess if your diet has features
that may warrant a shorter shelf-life we have put together a
guide. If you have further questions about your diet,
contact us at askanutritionist@harlan.com
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24. Can custom research diets be
irradiated?
Barrier facilities or certain animal models require sterile
diet. Most custom research diets do not withstand autoclaving;
however, we can arrange for qualified diets to be irradiated. The
irradiation dose range is 2 -5 MRad, or 20-50 kGy. Nominal fees and
extra time are involved. Please contact us for details about
irradiation costs and additional lead-time. Vacuum packaging may be
helpful in reducing irradiation-induced peroxide formation in high
fat diets. A nutritionist can assist you in determining if a
formula is suitable for irradiation. Irradiation will lead to
selective vitamin loss, and it is our practice to increase the
inclusion rate of certain vitamin mixes to ensure that the final
diet contains sufficient vitamins. Irradiated diets are
double-bagged.
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25. How can I order a diet
supplied to someone by Harlan Laboratories, and subsequently noted
in a research article?
Some diet formulas are fairly common or generic, and probably
are not considered confidential by those who use them, especially
when authors provide a product number. Formulas might be difficult
to trace without a product number, and then must be discussed with
a nutritionist. We will review each formula for history and
confidentiality.
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26. Can Harlan Laboratories
manufacture a diet made by another company?
Provide us with at the very least a description, preferably the
complete formula, and we’ll give you an assessment of our ability
to make that formula.
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27. Can any custom diet formula be
made in pellet form?
There are limitations for pelleting diets. The level and type of
fat, the carbohydrate composition, and the interaction of fat and
carbohydrate will impact our ability to pellet a diet. Consult a
nutritionist for more information about specific
formulas.
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28. What is "Vitamin-free" test
casein?
"Vitamin-Free" Test Casein is an alcohol-extracted casein
prepared from regular casein, and typically has 90-91% protein (%N
x 6.38), 0.1% fat, and 4-6% moisture. The alcohol extraction
reduces fat, fat soluble vitamins, and some of the B vitamins. This
protein source is most appropriately used in vitamin deficient
diets, and when researchers want to minimize "background fat" in a
diet. We have prepared this specialty ingredient for many years,
and continue to supply it to many labs. We will develop special
pricing on request for large quantities. Advance notice is
recommended for orders of 1,000 Kg or more. If you need this
ingredient, consider Harlan as your preferred source. Please see
our VFT Casein datasheet for more information about this
product.
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29. Does Harlan Laboratories sell
diet ingredients?
Yes. Some of the same high-quality ingredients used to produce
custom research diets can also be supplied to those who prepare
their own diets. See
Diet Ingredients for more information.
30. How do I cite a Teklad Diet
in a publication?
When citing Teklad diets, include a description, and a product
number - standard grain based diets are typically four numbers
while custom diets usually start with "TD" followed by 5
numbers. Use the following examples as a guide:
"Rats were maintained on minimal phytoestrogen diet 2016 Teklad
Global 16% Protein Rodent Diet, Harlan Laboratories Inc, Madison
Wisconsin USA, www.harlan.com"
"Obesity was induced by feeding Teklad high fat diet TD.06414
with 60% of kcal from fat, primarily lard, Harlan Laboratories Inc,
Madison, Wisconsin USA, www.harlan.com"
"Mice were fed Teklad vitamin D deficient diet TD.89123, Harlan
Laboratories Inc, Madison Wisconsin USA, www.harlan.com"
Each diet has a unique product number that will allow others to
quickly and easily obtain information about the diet used in your
studies by contacting tekladinfo@harlan.com or askanutritionist@harlan.com.