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Phytoestrogens and Chow Download PDF
Dosing Animals Via Diet Download PDF
Laboratory Animals- A Critical Part of In Vivo Research Download PDF
Diet-Induced Metabolic Syndrome in Rodent Models Download PDF
The common use of improper control diets in diet-induced metabolic disease research confounds data interpretation: the fiber factor Download PDF
Principles of laboratory animal science : a contribution to the humane use and care of animals and to the quality of experimental results Link to Book
Fiber Is Good for You. Now Scientists May Know Why. Download NY Times Article
Effects of Rodent Diet Choice and Fiber Type on Data Interpretation of Gut Microbiome and Metabolic Disease Research Download epub in Current Protocols in Toxicology

Diet Forms

OpenSource Diets are available in 1/2, 3/8 and 3/16 inch pellets or powder form. For liquid diet applications, the diet is shipped as a powder and water is added before use.

Pellets vs. Powder

Pellets Powder
Pellets are easier to feed than powder. Pellets can simply be thrown on top of the cage or even inside. Its easy to monitor the pellet supply and assure that animals have 24/7 access to feed. For food intake monitoring see BioDAQ. Powder requires special feeders. The feeders can be easily tipped and spilled, and the food can also be easily soiled by urine, feces or even saliva. So it is difficult to assure that the animals have 24/7 access to good clean food.
Pellets are a stable food stuff. They can be stored for months without losing quality. Powder has much greater surface area and the food spoils much easier. Powder also has a less obvious problem in as much as powders can become ‘unmixed’ over time. That is, smaller, more dense particles may sift to the bottom and less dense, fluffier parts may sift up, making the diet no longer homogenous and in the extreme nutritionally incomplete from top or bottom.
Pellets are homogeneous. Powder can be separated by the animal by pawing, sniffing and snorting, either intentionally or inadvertently.
Once pelleted compounds are ‘frozen’ in place and won’t become unmixed. Also the test compound is more stable in pellets as most of it is inside the pellet and away from direct air, light and humidity which cause most of the degradation of test compounds. Powder is often used by facilities that lack the equipment, personnel, money or interest in pelleting food. This is often done when researchers want to add test compounds to feed. Test compounds can easily sift out of the powder.
Pellets are dustless and cannot be inhaled. Powder can be (or is) inhaled by feeding animals causing respiratory irritation and infections. This is an often overlooked problem with feeding powder diets. This is especially likely with powders of standard chows, which unless irradiated are loaded with microbes.
Feeding pellets helps ‘wear’ incisors down. Powder fed rodents may develop overgrown incisors.

Typical Food Intake

Below are typical daily feeding requirements for several species. Use the numbers when calculating how much diet you will need to complete your study. If you have any question speak with one of our scientists for assistance.

Typical Daily Feeding Requirements Adult Animals/ grams per day Growing Animals/ grams per day
Hamsters  10-15  10-15
Mice   3-5 3-5
Rats   15-30 depending on strain  15-30 depending on strain
Non-human Primates (NHP)  2-4% of body weight depending on animal condition  2-4% of body weight depending on animal condition
Guinea Pigs   35 up to 35
Rabbits   110-175 for males and non-pregnant females
175-225 for pregnant/ lactating females
50-75 at 3-6 weeks
125-150 at 6-8 weeks