Minerals We regularly save £100/tonne by sourcing direct. Another big saving is taking out all the fancy bits and pieces you do not need. In the majority of cases a standard mineral fed at the correct rate will be ideal. Salesmen prey on problems and claim to have the answer in a bag. Cows need minerals, but if feeding a good quality standard mineral, deficiencies are rare. We usually reduce the cost of minerals, take out the fancy add ons and also reduce levels if appropriate. We then use metabolic profiling (blood testing) to assess the mineral status of the cow.