The invention relates to the use of an antibacterial compound, which is derived from alliaceae, as a natural additive in animal feed, intended as an antimicrobial agent in animal feed, and as an alternative, due to its antibacterial nature, to the use of antibiotics as growth promoters, proposing the use of the compound separately (purity greater than 95%), and encapsulated or supported on different inert materials or food coatings, and in that said compound preferably consists of propyl propylthiosulfinate and, in an alternative variant, of propyl propylthiosulfonate.