The method offered on this website doesn’t aim to promote a specific farm system.
PerfAlim’s performance indicators are based on the energy and protein quantities delivered by farms or territories.
They don’t take into account many other nutritional services (vitamins and fiber supply by fruits and vegetables, calcium supply by milk) or the level of sanitary or environmental quality (ex: sustainable or organic farming) offered by farms.
The food performance calculated by PerfAlim is the number of people potentially fed by the annual net quantities (sold quantities – bought quantities) of Edible Farm Commodities (EFC) delivered by a farm of a territory.
Each type of farm product is characterized by a nutritional value, estimated by three potential indicators: energy (in calories), proteins (in grams) or animal proteins (in grams).
The total amount of energy, proteins or animal proteins provided by the farm/territory production is then divided by the average nutritional requirement of one person (in energy, proteins or animal proteins). These requirements represent the quantities of energy, proteins and animal proteins recommended for a 70 kg man with moderated physical activity.
*EFC=Edible Farm Commodities (wheat, milk, suckler cow…).
- Examples of Edible Farm Commodities: wheat grain, milk, cereal-based feed products, meat etc.
- Example of non Edible Farm Commodities: wheat distiller’s grain, seed crops, straw, hay etc.
Calculation of the food performance
Straw has no value regarding energy or proteins because it’s not edible by humans (it’s the same for fodder).
The farm produces (sales – purchase):
- 699 000 Mcalories of energy, which respond to the requirements of 766 people per year ;
- 19 000 Kg of proteins (both animal and vegetal) which respond to the requirements of 995 people per year ;
- 2 300 Kg of animal proteins (coming from milk, meat) which respond to the requirements of 273 people per year.
Therefore, it can feed up to 995 people per year, based on the global proteins delivered by the farm (we have kept the best score between the three indicators).
Nutritional values of farm commodities
The nutritional value of farm commodities is the content of energy and global proteins (proteins contained in the food). All values come from the FAO’s Food Balance Sheet, released again in 2007 in France.
For all proteins coming from vegetal products (cereals, pulses, fruits and vegetables…), a low average of 80% has been chosen as nutritional efficiency factor, inspired by the numbers found in the FAO’s Protein and Energy Requirements rapport. 95 % is the nutritional efficiency factor chosen for all proteins coming from animal products (meat, milk, eggs).
Nutritional values of animal products are based on a live weight hypothesis and the average carcass yield of each animal, estimated according to many sources (Institut de l’Elevage, Uniporc, FranceAgriMer, SCEES). The estimation of unfinished animals considers their own live weight and the carcass yield of the equivalent fattened animal.
Nutritional values of compound feed take into account the levels of incorporation of farm commodities calculated by the Ariane calculator. This is an optimization tool for food formula, integrated in the “Prospective Aliment” model developed by CEREOPA in 2004. The price conjuncture of March 2010 is taken into account in its current version.
The energy and protein requirements of an average 70 Kg person with moderated physical activity are used by PerfAlim. This represents an average energy requirement of 2500 kcal and a protein requirement of 52.5 g really useable by the organism (highly digestible proteins with adequate amino acid composition). With the average nutritional efficiency factor estimated at 85 % for all feed products, a supply of about 62 g of global proteins brought by alimentation is found. For the average requirement of animal proteins we use 40% as the average portion of animal proteins contained in the global proteins supply of a person (world average). Therefore, we find an average requirement of animal proteins really useable by the organism of 22.5 g per individual and per day.
The food performance profiles are obviously very variable regarding the production type. PerfAlim’s goal isn’t to legitimate any system to the detriment of others (which would be impossible due to the context variability), but to highlight their complementarities in a territory. PerfAlim could be used in a farm to compare the consequences of different production techniques on its food performance (simulation of multiple scenarios).
It’s also important to remember that PerfAlim doesn’t take into account the future of farm commodities after the farming production step. A ton of wheat will be considered as it is when exiting the farm, and not as bread or pasta: we really consider a farm nutritional potential.