Halophytic shrubs accumulate minerals associated with antioxidant pathways

Halophytic shrubs from the Chenopodiaceae family are planted by farmers in Mediterranean climate and semi‐arid farming systems because they produce year‐round feed for livestock and grow on poor‐quality soils that are unfit for cereal or traditional pasture production. Halophytes have evolved in environments that exert a high oxidative stress and through this have a high antioxidant capacity. The higher antioxidant capacity of halophytes means that they could have elevated concentrations of the minerals and vitamins associated with antioxidant defence and, as a consequence, may be a good source of antioxidant minerals and vitamins for sheep, cattle and goats. It was hypothesized that a range of halophytic shrub species and accessions within species will contain copper (Cu), manganese (Mn), selenium (Se), zinc (Zn) and sulphur (S) concentrations that will exceed the requirements of grazing ruminants. Concentrations of these minerals were measured across nineteen shrub accessions representing seven widely distributed Australian chenopod species: Atriplex amnicola, Atriplex nummularia, Atriplex rhagodioides, Chenopodium nitrariaceum, Enchylaena tomentosa, Maireana brevifolia and Rhagodia preissii, as well as Eremophila glabra from the Scrophulariaceae family. Measurements were made at one location in spring and winter and at another location in winter only. Concentrations of the elements analysed almost always exceeded requirements and ranged up to 610%, 952%, 1840%, 590% and 250% of the requirement for grazing sheep for Cu, Mn, Se, Zn and S respectively. These results indicate some shrubs have significant potential for use as an antioxidant mineral supplement for ruminants.