Antler growing cycles

Overview of phases of growth cycle

Each year, antlers drop off and fully regenerate in a growth cycles.

Each antler growth cycle includes:

initiation
rapid growth (velvet phase)
mineralisation
velvet shedding
antler casting

Various factors control the different phases

Control of antler growth

Being male secondary sexual characters, both pedicle formation and the subsequent antler growth cycle is under the control of testosterone. Testosterone levels at the various stages of the growth cycle are shown in the following table.

Stage	Testosterone level
stimulation of pedicle formation	high
commencement of new antler growth	low
rapid antler growth	barely detectable
antler calcification	increasing
velvet shedding	high
antler casting	decreasing

The factor responsible for stimulating antler growth is insulin-like growth factor 1 ('IGF1'). The timing of the peak of IGF1 production is regulated by day length but the key factor influencing the amount of IGF1 production is nutrition. Good nutrition is therefore required to grow big antlers to the animal's full genetic potential. For more on the role of nutrition, see the section on quality.

Show me the science
For a detailed discourse on the science of antler growth, see Antler Growth: Nutritional and Endocrine Factors Fennessy, P.F. and Suttie, J.M.