At the bottom is a picture of mouse hair follicles in a mature anagen state. These pictures are all taken at the same magnification so you can see that there is a considerable cell growth during the hair cycle to transform from a small telogen follicle into a large anagen follicle. Other species have still more patterns of hair growth. Merino sheep have hair follicles permanently in the anagen growth stage, they do not cycle through growth and rest. The result is Merino sheep must be regularly sheared regardless of whether the wool is needed or not.
Some species have hair growth cycles that take their cue from the seasons.
Arctic foxes will produce a summer coat and a winter coat so their hair follicles have to go through two complete hair cycles each year and switch the type of hair fiber that they produce. What coordinates the change in hair production and how the seasons act on the hair follicles is not understood. The influence of the hair cycle on the thickness of mouse skin. Am J Vet Res. Morphological changes associated with the growth cycle of vibrissal follicles in the rat.