A system (1) to adjust a predetermined dosage of main livestock feed products in a predetermined feed recipe, said feed recipe comprising one or more feed dosages, each of which is indicative of a predetermined amount/weight of a corresponding main feed product in said feed recipe. The system comprises a memory device (6) for storing said predetermined feed recipe, a meteorological monitoring system (7) suitable for determining one or more meteorological parameters in the storage areas (8) of the main feed products and a processing unit (9), configured to: determine a first value that is indicative of the humidity in each said main feed product as a function of the meteorological parameters associated with the related storage area, determine a differential value that is indicative of the difference between the first value and a second value that is indicative of a reference humidity of said main feed product, and adjust the feed dosage associated with each main feed product in said feed recipe on the basis of said differential value of humidity in the main feed product.
