A big practical advantage of Rockies is that there is no need to check daily consumption. Their exceptional palatability lets your stock regulate the amount they need, and our own data collected over many years is a reliable indicator of consumption.
For example, you can calculate that sheep and goats will take 5-10 grammes per day, at a maximum cost of less than 2 pence per day per animal. That consumption of course includes the correct daily dosage of essential trace elements and minerals.