Minerals lacking…
Minerals lacking…
SOME minerals contain only half the expected levels of trace elements and producers should check that the supplement supplies what is required.
ADAS nutritionist Pete Kelly warns that the permitted legal tolerances for the level of trace elements sold in mineral supplements are being exploited by some manufacturers to save costs.
Speaking at a Devon Grassland Society meeting in Exeter, he said that the legal tolerance for trace elements is plus or minus 50%.
"This legislation dates back to when analytical predictions were less accurate, but analysis is now accurate and some manufacturers are only supplying 50% of the expected level of trace elements."
Mr Kelly cited one case where the level of selenium in a mineral had been specified at 25mg/kg for a dairy herd of known deficiency. But after feeding the mineral for three months a blood test of cows showed the deficiency had worsened. Analysis of the mineral showed half the specified level of selenium.
Although some companies are supplying the required level of trace elements, he urged producers to check the formulation supplies what is required and that the tolerance regulations are not exploited. When in doubt a sample of the mineral can be analysed for about £25, he suggested.
It is not always cheaper minerals that are at fault, said Mr Kelly. For example, products to balance maize gluten will be cheap anyway, but those containing phosphorous will be more expensive.