Quiz 1B : Optimization of the formulation of animal feed

Length : around 5 minutes

« An animal feed company produces concentrates for cattle using various types of ingredients : protein crops (peas), cereal (maize) and cattle cake (soya-bean).

The concentrates obtained must have a minimum guaranteed content of TNM (Total Nitrogenous Matter) and fat as well as maximum mineral matter and crude fibre contents

Minimum contents TNM (g/kg) Fat (g/kg)
Concentrate 200 25
Maximum contents Mineral matter (g/kg) Crude fibre (g/kg)
Concentrate 70 65

The content of each of these components is known for every ingredient.

 

Contents TNM (g/kg) Fat (g/kg) Mineral Matter (g/kg) Crude fibre (g/kg)
Maize 81 37 12 22
Peas 207 10 30 52
Soya-bean cakes 453 19 64 60

The cost of maize is 148€/T, that of peas 195€/T and soya-bean cakes 355€/T. »

Source : P. Haurez, Utilisation des protéagineux dans l’alimentation des bovins viande, synthèse réalisée par l’Institut de l’Elevage, 2002.

It is possible to develop a linear programming model which helps determine the optimal formulation of a kilo of concentrate so as to respect the guaranteed contents while minimizing production costs.

Consider the linear programme and answer the questions.

Let C be the cost of concentrates (euros)
M the amount of maize used in a kg of concentrate (in kg)
P the amount of peas used in a kg of concentrate (in kg)
T the amount of soya-bean cakes used in a kg of concentrate (in kg)

How can the sentence “the goal of the company is to minimize its production costs” be written in algebraic form ?

The mineral equation says that the total mineral content per concentrate unit must at most be equal to the guaranteed content and is written as follows :

The TNM equation says that the TNM total content per concentrate unit must at least be equal to the guaranteed minimum content and is written as follows

The fat equation says that the fat total content per concentrate unit must at least be equal to the guaranteed minimum content and is written as follows :

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« An animal feed company produces concentrates for cattle using various types of ingredients : protein crops (peas), cereal (maize) and cattle cake (soya-bean).

The concentrates obtained must have a minimum guaranteed content of TNM (Total Nitrogenous Matter) and fat as well as maximum mineral matter and crude fibre contents

Minimum contents TNM (g/kg) Fat (g/kg)
Concentrate 200 25
Maximum contents Mineral matter (g/kg) Crude fibre (g/kg)
Concentrate 70 65

The content of each of these components is known for every ingredient.

 

Contents TNM (g/kg) Fat (g/kg) Mineral Matter (g/kg) Crude fibre (g/kg)
Maize 81 37 12 22
Peas 207 10 30 52
Soya-bean cakes 453 19 64 60

The cost of maize is 148€/T, that of peas 195€/T and soya-bean cakes 355€/T. »

Source : P. Haurez, Utilisation des protéagineux dans l’alimentation des bovins viande, synthèse réalisée par l’Institut de l’Elevage, 2002.

It is possible to develop a linear programming model which helps determine the optimal formulation of a kilo of concentrate so as to respect the guaranteed contents while minimizing production costs.

Consider the linear programme and answer the questions : Click on “Start quiz”.