Purina TestDiet® can add compounds to virtually any diet at no extra cost, because we make all diets fresh to your order within 7-10 business days. 

Be particularly mindful of correctly determining dosage: it is important to determine approximately how much your animals ingest, not how much they consume.  Typically animals spill part of their food, some, such as mice, quite a large percentage (10%-30%+); dosage should be based on the amount actually eaten by the animal.  We suggest that a short (few day) informal food intake survey be conducted of a representative sample of your animals, accounting for the amount of food leaving the hopper reduced by the amount spilled in the tray below.

Then the dosage percentage should be based on the ingestion amount.  For example, a mouse may "consume" (use up) 5 grams per day, but actually only ingest 4 grams.  If the dosage is based on a "5gram/day" assumption, the animals will only receive about 80% of the intended dosage; if based on a "4 gram/day" assumption, they will receive the full amount of the intended dosage.

Calculating the Concentration of Compound in Diet
To achieve your desired level of dosing, determine these variables
and apply them to either one of two equations.
Typical Examples
MouseRat
First, Determine Daily Dose - DD   
mg of Compound per kg of body weight  - CK10 mg10 mg
Body Weight of animal (gm)  - BW35 gm300 gm
CK(mg) x BW(gm) x .001 = DD  
Daily Dose of Compound (mg)  - DD0.35 mg3 mg
   
Second, Determine Concentration in Diet - CD   
Daily Dose of Compound (mg) - DD0.35 mg3 mg
Daily Food Intake (gm) - FI3.5 gm20 gm

By applying one of two equations -
  
Either to determine mg per kg diet / ppm:   
   (CKmg x BWgm) / FIgm = CDmg per kg of diet = ppm100150
   
Or to determine percentage of diet:  
   {(CKmg x BWgm) / FIgm}/10,000 = CD% of diet0.01%0.015%