1. A system (1, 24, 34) of ventilation ducts for reducing air pollution in a livestock building (25, 33, 52) having at least one surface (3) for keeping animals, or around such a building, wherein said system (1 , 24, 34) of the ventilation ducts is located at least partially under at least one surface (3) for keeping animals and contains waste receiving means (2) intended for receiving waste (17, 20, 32) with at least part of at least one surface (3) for keeping animals and / or through it, while the system of ventilation ducts (1, 24, 34) provides a pressure gradient across the width of the waste receiving means (2), the specified air pressure gradient being created by the pressure drop between the first long side (10) and the opposite second long side (11) the waste receiving means (2), and the ventilation duct system comprises a first duct (7) with a first inlet end and an opposite first outlet end, and at least one first ventilation hole (14) for communicating at least by transmitting gas with at least a waste receiving means (2), characterized in that it further comprises a second duct (8) with a second inlet end and a second outlet end, and at least one second ventilation opening (15) for communicating at least at least by transferring the gas with at least the waste receiving agent (2) .2. The ventilation duct system (1, 24, 34) according to claim 1, characterized in that the waste receiving means (2) has at least one first passage (12) in the first long side (10) and at least1. Система (1, 24, 34) вентиляционных каналов для уменьшения загрязнения воздуха в животноводческой постройке (25, 33, 52), имеющей по меньшей мере одну поверхность (3) для содержания животных, или вокруг такой постройки, причем указанная система (1, 24, 34) вентиляционных каналов расположена по меньшей мере частично под по меньшей мере одной поверхностью (3) для содержания животных и содержит принимающее отходы средство (2), предназначенное для приема отходов (17, 20, 32) с по меньшей
