Feed costs are a major cost of milk production (approx. 30%) and monitoring results are frequently available on farm. The principle analysis outputs are the cost of the concentrate (or equivalent) in £/Tonne (range £180 to £250 per tonne as at Feb12) and the amount fed per litre (0.26 to 0.56 kg/litre milk). Such figures vary systematically with calendar month and herd milk yields so should be benchmarked accordingly. Two key drivers for cost-effective feeding are overall feed intake (ranging from 0.35 kg concentrate per litre milk with high intakes to 0.70 kg/l for low intakes) and forage energy content (ranging from 0.45 kg concentrate per litre milk with low quality to 0.28 kg/l for high quality forages). These two drivers are largely within the farmer's control.