Frequently Asked Questions |
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A: 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. Q2: What are custom research diets? A: 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. Custom research 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 compound. The typical lead time between order and shipment is two weeks. For additional information about custom research diets please visit our Custom Research Diets Website. A: A purified diet uses refined ingredients such as casein, sucrose, cornstarch, and cellulose. These 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. A: 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 Teklad certificate of analysis signed by a nutritionist is made available to the customer. For more information see Certified Diets. Q5: What is the shelf-life of our diets? Custom research diets are generally more perishable and should be stored at or below 40 degrees Fahrenheit preferably with a humidity at or below 70%. Given these storage conditions many diets may be fed up to six months after their date of manufacture. However, custom research diets vary significantly in their formulation. There may be certain features of a diet that merit a shorter shelf-life. If you have questions as to the shelf-life of your diet contact technical services at askanutritionist@teklad.com. Q6: What are fixed formula diets? A: 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. A: Harlan Teklad Global Diets® are a unique range of laboratory animal diets which have Global availability. These diets are manufactured exclusively at our standard diets facilities in the United States, the United Kingdom and Italy using fixed formulas and the same stringent requirements for raw materials. Harlan Teklad Global Diets now offer companies with research operations in several countries the ability to standardize their diets without sacrificing quality. For additional information visit Harlan Teklad Global Diets®. Q8: Does Harlan Teklad have a quality program ? A: At Harlan Teklad 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 Teklad utilizes its own network of company owned and operated distribution centers throughout the US and Canada rather than use outside distributors. Q9: Does Harlan Teklad offer irradiated products? A: Harlan Teklad 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 Teklad irradiates all products at a minimum dose of 2.0 Mrad (20kGy) and a maximum of 5.0 Mrad (50 kGy). For information visit Irradiated Diets and Bedding. Q10: How do autoclavable diets differ from non-autoclavable diets? A: 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. A: 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. Q12: Does Harlan Teklad offer diets that are phytoestrogen free? A: 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. However, Harlan Teklad offers three diets that exclude ingredients such as alfalfa meal and soybean meal which are known to contain large amounts of phytoestrogens. The Harlan Teklad Global Rodent Diets 2014, 2016, and 2019 while not completely “free” are best described as phytoestrogen minimal diets. Quarterly testing of these diets for isoflavones (phytoestrogens from soybean) typically reveals less than detectable levels (< 5ppm). For some perspective, most traditional rodent diets contain from 200 to 500 ppm isoflavones. Phytoestrogen minimal diets such as 2014, 2016, and 2019 are generally acceptable for studies where phytoestrogens are of concern. |
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