Relationships between some soil parameters and the blood glutathione peroxidase activity of grazing sheep

The relationships between some soil parameters and blood glutathione peroxidase (GSHPx) activity in 15-day-old lambs was studied on 18 sheep farms. Soil samples were analysed for the proportions of sand, silt and clay, pH, and the concentrations of calcium, phosphorus, iron, nitrogen and sulphates. On the farms where the lambs had adequate GSHPx activity (> or = 130 i.u./g Hb) the soils contained significantly more clay, phosphorus and sulphates, and significantly less iron and nitrogen, than on the farms where the lambs did not have adequate GSHPx activity.