The output of deer stag’s pilose antler is closely linked to their age.Deer’s ability of producing the pilose antler cnperiences 3 main processes: increaes peak - decrease. With growing up of their bodies they are physically affect. And going throug 3 periods of time. 1. Quickly increasiing pilose antler. (from age 3 to 6).2.Producing steadly (from age 7 to 10)3.The output of pilose antler decrease gradually (after 10).The cost of raising is alse in connecti with age. The changing of its cost shows the curve like bathtub.With the help of adding up the average cost curve of nroding pilose antler (C) and in comey horizontal line of selling the unit prod ucts (R) We can decide the using years and eli manating age of the deers.Using y = a + bx + cx1 + dx3retruned mod el, we can obtain" c- R -Q"