In the not so distant past, feed manufacturers used to balance their feeds using hand calculations and often relied on tedious trial and error methods. The availability of commercial computers by the end of the 1960s meant that complex mathematical models can be solved much more easily and within a short duration of time. Twenty years later, the arrival of the personal computers provided affordable feed formulation solutions to the feed industry. Advancements in computer technology, mathematical modeling and animal nutrition have resulted in vast improvements in the last 20-25 years in the way feeds are formulated.
Agri Visser Consultancy gives a new meaning to
least cost formulation: TailoredDiet is freeware.
What is least-cost formulation?
Least-cost feed formulation is combining many feed
ingredients in a certain proportion to provide the target animal
with a balanced nutritional feed at the least possible cost.
Though least-cost formulation is a mathematical solution
based on linear programming, it requires the professional
knowledge of animal nutritionists who take into consideration
the nutrient requirements of the target animal and its capability
to digest and assimilate nutrients from various, available
ingredients. A highly specialized feed application such as aqua
feeds also require that a number of special considerations such
as the pellet size and feed floatability are considered. Aqua
feed formulators also need to be aware of the variations of
nutritional requirements for different species such as catfish,
shrimp, tilapia, eel, bass and others at various stages of their
lifespan. The linear programming performs what is designed to
do basis the information put in by the formulator. So, in
essence, the formulation program is only as good as the nutrient
and ingredient parameters entered into it.
Agri Visser Consultancy gives a new meaning to
least cost formulation: TailoredDiet is freeware.
What to expect from least-cost formulation
Software?
There is a broad choice of feed formulation software
packages in the market. The software range from simple,
spreadsheet-based solutions to sophisticated and complex
packages designed for large feed manufacturers that require
multi-site, multi-server, and multi-blending capabilities. New
and innovative add-on applications are being developed and
introduced into the market every year. The software packages
may also provide modules for inventory control, production,
and interfaces to accounting systems among other features.
Some feed formulation software are specifically designed for a
certain species and they may provide tables of nutrient
requirements or models of growth for those specific animals.
Further, improvements in the look and feel of the
software and seamless integration with other functionalities
related to formulation also occur routinely. These applications
and improvements enable feed formulators to perform their
jobs much more efficiently.
Agri Visser Consultancy gives a new meaning to
least cost formulation: TailoredDiet is freeware.
Basic features
For least-cost feed formulation software to be effective it
should offer the following basic features that are applicable to
all species. At this point it is important to keep in mind that feed
formulation runs on data that have been entered into it by the
user. The final feed formula will only be as accurate, as the
initial information that was input by the user.
(1) Available Ingredients
All feed formulation software provide a way of entering
and managing the ingredients which are available for inclusion
in the formulas. Available feed ingredients are listed along with
their unit price. Depending on the software being used, optional
ingredient properties such as the ingredient types, alternate
code names, and applicable species may also be entered.
(2) Nutrient Composition
Each feed ingredient available for inclusion in the
formulas should have corresponding nutrient composition
data. The nutrient values are preferably derived from chemical
analysis of representative samples of the ingredient. When the
nutrient composition is not available, tables of feed
composition using average or typical values are used.
(3) Formula Specifications
Specifications are set for each formula to be solved by the
least-cost formulation software. Formula specifications
generally define the nutrient levels desired in the formula and
the ingredient inclusion levels. Either a lower limit and/or an
upper limit for each nutrient and ingredient are set.
Formulation
Once all the above necessary information is provided, the
feed formulation software will produce formulas that meet the
desired specifications at the lowest possible cost (Figure 1).
A requirement for proper formulation, however, is that the
formula result must be feasible both from a mathematical and a
nutritional standpoint. If infeasible results are obtained the
ingredient and nutritional composition should be carefully
scrutinized to make sure the solution is nutritionally acceptable
for the target species.
One of the most important uses of least-cost feed
formulation is in choosing among the available ingredients to
be used, based on their nutritional composition and cost. Many
times one ingredient can be substituted by another with similar
nutritional value. The software helps the user to achieve the
highest profit margin when market conditions favor the use of
one ingredient over the other. A number of tools are useful in the
analysis of formulation results.
Agri Visser Consultancy gives a new meaning to least cost formulation: TailoredDiet is freeware.
Formulation analysis tools
(1) Marginal Price Changes
For those ingredients that were not included in the
formula solution, the least-cost formulation software indicates
how much the cost of these ingredients will have to fall before
they can be included in the formula. This cost change is called
the marginal price change of the ingredient.
(2) Shadow Prices
Shadow price (Figure 2) of an ingredient is calculated by
subtracting the marginal cost change from the current
ingredient cost. This amount represents the cost of the
ingredient at which the ingredient can be included in the
formula. Ingredients that are included in the formula results
have a shadow price of zero.
Similarly, the change in formula cost with a change in a
nutrient constraint is called the shadow price of the nutrient.
The shadow price of a nutrient is zero if the level of nutrient use
is not equal to the constraint level.
(3) Parametric Price Changes
An important analytical use of least-cost feed
formulation software is to observe the impact of changing
ingredient prices in the formula solution. This allows the user to
determine how much of an ingredient would be used if the
ingredient were available at a different price. To accomplish
this analysis, the user can change the ingredient price and resolve
as many times as necessary. Some feed formulation
software allows the generation of summary graphs called price
maps (Figure 3), which are the result of plotting the formula
costs at different ingredient prices.
Advanced features in formulation software
(1) Nutrient Factoring
The ability to specify that several nutrients must exist in
the resulting formula in relation to one another is called
Nutrient Factoring. Advanced least-cost feed formulation
software solutions provide this capability which allows ratio
between two nutrients, for example calcium and phosphorus.
The ability to specify nutrients in proportion to one another is
another application of this function. For example, the user can
specify that amino acids be proportional to the total amount of
protein in the formula.
(2) Optimum-Density
This is a function of least-cost feed formulation that
attempts to formulate with specific proportions among
nutrients by relaxing the weight constraint of the formula,
based on the theory that animals will consume feed to
maintain a constant energy intake regardless of the energy
level of the feed.
(3) Multi-blending
Sometimes feed formulators are faced with the
problem of having limited amounts of some ingredients. An
advanced feature of some least-cost feed formulation
packages is multi-blending, which allows more than one
formula to be solved at once, taking into consideration the
ingredients that are available in limited qualities. The
software then optimizes the allocation of the scarce
ingredients to different formulas in order to achieve total
least-cost solution.
Agri Visser Consultancy gives a new meaning to least cost formulation: TailoredDiet is freeware.