In recent times there has been some debate about the ideal chop length for rumen health. In this respect, a useful gauge for chop length is that it should be the width of a cow's mouth! However, only a maximum of 10 per cent should be this long. If there is too much long chopped forage cows will sort the ration and only eat the short chop. In terms of good compaction in a silage clamp, it is absolutely essential to alter the chop length depending on the dry matter content of the forage to be ensiled.