There is no doubt that the provision of trace elements is essential to maintain good animal health and performance.
But it's not just providing trace elements that's important - it's making sure that every animal in a herd or flock receives them, especially when they are at grass or eating conserved forage.
Grass is the most economic and abundant animal feedstuff, but it cannot be relied upon to supply enough key trace elements. Many soils are deficient in micro-nutrients such as copper, selenium and iodine. Others may have an excess of the troublesome molybdenum or iron.
Unless these problems are corrected, health and performance will suffer and optimum returns will never be achieved.