Purified Diets vs Grain-based Diets

Purified feed mainly refers to feed composed of highly purified and refined raw materials. One raw material provides a single nutrient. Because the nutritional composition and raw material sources are highly stable, purified feed is used to develop and establish good feeds that are highly simulated for clinical disease. For this reason, it is generally used as a model feed.

Compared to purified feed, the composition of cereal feed is derived from plant materials. In the field of experimental animal nutrition science applications, grain feeds will appear in journal literature or ordinary scientific discussions under different names, such as roughages, mixed feeds, "Chow" feeds, "Grain-based" feeds, and dietary feeds. 

In terms of feed production, the two are also very different. The raw materials used in cereal feed come from crops or by-products of crops. Due to the difference in harvest time and place, the nutrition composition between different batches has great variation. In addition, the nutrient quick ingredients listed on the cereal feed packaging bag are from a single sampling data, and most cereal feed manufacturers do not actually measure the raw materials used in each batch. Therefore, without the use of fixed nutritional ingredients, the lack of actual nutrient composition data for each batch of production makes it more difficult to quantify nutrients. The opacity of the formula makes it difficult for researchers to control the experimental variables.

Diet and Imaging


Diets and Imaging

Use of OpenSource Diets and In Vivo Imaging 

In order to produce high quality in vivo images using fluorescence imaging technologies, it is important to have as low background signal as possible. It has been shown that laboratory animal diets containing chlorophyll fluoresce at 680 nm, which can interfere with the imaging of many common in vivo fluorophores such as GFP or Alexafluor 650 and 680. The confounding fluorescent signal they produce as they pass through the gastrointestinal tract makes quantification of true signal difficult. It appears that unrefined chlorophyll-containing ingredients, particularly alfalfa, are responsible for this ‘noise’.

Purified Ingredients

The idea behind purified ingredient OpenSource diets is simple: each nutrient is supplied by a separate, purified ingredient. Because these ingredients are refined materials, each containing one nutrient, (as opposed to the less refined chow ingredients) this allowed research nutritionists to define the nutritional requirements of animals by selectively removing one nutrient at a time from the diet. This also means that the possible modifications one can make to an OpenSource diet are virtually limitless. This is also what continues to make OpenSource diets powerful research tools and why so many scientists have turned to them in recent years.

Typical Purified Ingredients

Proteins Carbohydrates Fats Vitamins Minerals Additives
Casein Sucrose Lard Vitamin E acetate Dicalcium Phosphate Genistein
Soy Protein Isolate Fructose Corn Oil Folic Acid Sodium Selenite Daidzein
Egg White Protein Corn Starch Safflower Oil Vitamin A acetate Cholesterol
Menhaden Oil Vitamin D3 Your Compound