In the non-therapeutic method livestock animals, used in agri- or aquaculture for producing livestock products, are made to ingest at least one product comprising a PPAR/RXR heterodimer activator and/or a precursor thereof over such a period of time and in such an amount that the PPAR/RXR heterodimer activator is accumulated in the livestock animal. In this way, livestock products such as meat, milk and eggs having an increased PPAR/RXR heterodimer activator level can be obtained. The PPAR/RXR heterodimer activator is phytanic acid, a metabolite of phytanic acid, a derivative of phytanic acid or of said metabolite, or a combination thereof. In order to accumulate the PPAR/RXR heterodimer activator in the livestock animal, a predetermined minimum amount of said product, in particular of phytol, is given to the livestock animals over at least one period of at least three days.