A young stag's first antlers are normally small spikes and at this stage he is known as a 'knobber'. Stags over two years old begin to grow branching antlers and more points or 'tines' are added each time a new set of antlers is grown, until there are twelve points, the head of antlers then being a 'royal'. Antlers are made of solid bone and as soon as they are shed, usually in March or April, a skin (called velvet) grows over the bony stump; this is richly supplied with blood vessels and nerves and bone is laid down within it. When the antlers have reached full size the blood supply to the velvet is cut off. The velvet begins to die and the stag rubs it off against branches and young trees, and eats it.
The size of the antlers is related to the quality of the diet of the stag. Those living in forests have larger antlers than those grazing on moorland. If some minerals or vitamins are lacking then the antlers may be stunted. Stags in the Highlands chew their old antlers when they drop off to replace the minerals needed to grow a new set, which are missing from the peaty soil of their habitat.Read More: Red Deer and Humans