Body weight was recorded with a circular scale suspended from a tripod. The animals were suspended from two straps, one behind the front legs in the sternum area, and the second strap anterior to the rear legs in the inguinal area. According to our results, there is a relationship between age and height to withers. Height at withers indicates how fast or how slow a young alpaca is growing. In some instances, withers height may also indicate potential crosses with llamas or guanaco.
Male alpacas are slightly taller than females.
In addition, there is no difference in height to withers among colors of alpacas. It is sometimes said that suris and huacayas have different physical characteristics. It is a visual perception only. Because the forehead of the suri alpaca often appears flat and because it does not have an elevated wool cap like a huacaya, its ears appear to be longer than those of a huacaya. By contrast, the huacaya has a forehead with perpendicular-lying fiber, its ears may appear to be shorter than those of the suri, and in general the huacaya appears shorter than it actually is.