It is not the tools that define the master, but good tools definitely help a good artisan perform best. The same applies to nutritionists and their feed formulation software.
Feed formulas were calculated long before computers and software came into play. In fact, today, it is highly recommended for anyone starting in feed formulation to begin without a computer using simple methods to calculate a basic formula. Such an exercise will help identify the major cornerstones of formulation, the constraints of the problem, and the balance between space (or weight), cost and nutrient concentration. So, let us start from the beginning.