How does a male horse attract a female horse?

Stallions typically get the attention of mares in three ways. The first is through a show of strength, i.e. winning fights with other stallions, which is usually not necessary in most circumstances. The second is by spreading his scent, which can be accomplished by expelling waste or, preferably, kicking up dust in the mare's general direction. The third, and perhaps the most and least subtle at the same time, is by forcibly extending his penis to its full length by repeatedly kicking it, so the mare can easily judge whether or not he's as good as he claims.