Due to the limitation of the nutrients contained, a single feed raw material cannot meet the nutritional needs of experimental animals. Therefore, different feed raw materials should be selected and scientifically proportioned according to the nutritional needs of various experimental animals at different physiological stages and the nutrient content of each raw material, so that all the nutrients provided can meet the feed standards of experimental animals. The feed prepared according to the standardized production process is called (full price) formula feed.

Experimental animal feed prepared with different types of raw materials

(1) Cereal feed: raw materials come from crops or by-products of crops (plant and animal raw materials), which is the basic feed for the routine feeding of experimental animals.

(2) Purified feed: feed prepared from refined raw materials, such as casein as protein source, sugar or starch as carbohydrate source, cellulose as crude fiber source, and then mixed with essential trace elements such as high-purity vitamins and minerals. Purified feeds are usually used only to induce disease models in experimental animals.

(3) Chemical definition feed: high purity amino acids, monosaccharides or disaccharides, fatty acids or triglycerides, reagent grade minerals and vitamins are used as raw materials, which is only applicable to the experimental use limited by special nutrients. However, due to the high production cost, the use is greatly restricted.
Design of feed formula

Feed formula is to scientifically formulate the proportion of various raw materials according to the nutritional needs of experimental animals at different physiological stages, the source, price and special experimental purposes of feed raw materials.

Data required for designing feed formula

(1) For the nutrition standard of experimental animal feed, refer to the formula feed standard issued by domestic or international authoritative institutions.

(2) The production enterprise shall monitor and analyze the nutrient content of all purchased raw materials according to the feed composition analysis value specified by the feed management department.

(3) For the formulation design for disease model induction or special experimental purposes, priority should be given to the feed formulation in the relevant literature.
Principles of designing feed formula

(1) No antibiotics or drugs should be added to the conventional feed to ensure the stability of the experimental data.

(2) The design of feed formula should not only consider the basic nutritional needs of experimental animals, but also consider the quality and palatability of raw materials.

(3) When purchasing raw materials, try to select domestic high-quality raw materials and pay attention to the purchase cost of raw materials.

Calculation method of feed formula

Feed formula calculation technology is the product of the combination of modern applied mathematics, animal nutrition and feed science. It is the fundamental means to realize the rational allocation of feed and obtain the feed formula with high efficiency and low cost. The conventional calculation method is mainly trial and error method suitable for manual calculation. In recent years, the method of solving linear programming problems in conditional production enterprises has been successful and is being popularized.

No matter what method is used to design the feed formula, the proportion of feed raw materials is only the theoretical data based on the raw material composition, which must be verified by laboratory testing and feeding experiments. The validated feed formula for laboratory animals should be kept stable for a long time.