There is provided a method of growing seeds in a hydroponics apparatus to provide animal feed, wherein the hydroponics apparatus includes a plurality of elongate trays for receiving seeds, an environmental control arrangement for controlling in operation a temperature and humidity of the plurality of elongate trays, and a nutrient solution supply arrangement for providing a nutrient solution to the seeds on the plurality of trays, characterized in that the method includes: (i) preparing the seeds by removing loose chaff therefrom, and removing remnants of husks and broken seeds； (ii) exposing the prepared seeds from (i) to gaseous ozone in a sealed gaseous exposure chamber, wherein the ozone is provided to the prepared seeds in either a) a concentration in a range of 5 p.p.m.v. to 10 p.p.m.v. for a period in a range of 50 minutes to 60 minutes or b) a concentration in the range of 10 p.p.m.v. to 20 p.p.m.v. for a period in a range of 1 minute to 30 minutes, in a condition of relative humidity in a range of 40% to 95%, and at an ambient temperature in a range of 12°C to 28°C； and (iii) providing exposed prepared seeds from (ii) to the plurality of elongate trays for growing the exposed prepared seeds to provide grown plant material for use in producing the animal feed.L'invention concerne un procédé de culture de graines dans un appareil hydroponique visant à fournir des aliments pour animaux. L'appareil hydroponique comprend une pluralité de plateaux allongés destinés à recevoir des graines, un agencement de régulation des conditions ambiantes destiné à réguler, lors du fonctionnement, la température et l'humidité de la pluralité de plateaux allongés, et un agencement de distribution de solution nutritive destiné à fournir une solution nutritive aux graines disposées sur la pluralité de plateaux. L'invention est caractérisée en ce que le procédé comprend : (i) la préparation des graines par élimination de la menue paille libre présente dans celles-ci et l'éliminatio
