Eye-Lens Weight as an Indicator of Age in Australian Goats, Capra-Hircus L

Abstract

The age in days of goats from Canegrass Station, S.A., and Condobolin, N.S.W., can be estimated from their paired dry eye-lens weights (E, in grams) by the formula: A = (357.5+46 lnE)/(0.002714-InE), where A is age since conception. The formula is based mainly on the eye-lens weights of 88 feral goats from Canegrass whose ages had been estimated by a method based on reproductive patterns. These data were supplemented by the lens weights of 20 known-age domestic goats from Condobolin. The formula incorporates an adjustment to reduce statistical bias. The lenses in goats from Avenue Range, S.A., grew at a different rate. The relationship between eye-lens weight and age was not influenced by differences in sex or rate of body growth.