This project will look for ways to measure lamb production based on economic benefits rather than just on growth factors. Project participants include five owners and breeders of registered and commercial breeding stock and one commercial producer who will supply ewes. They will build their “economic index” for superior sires by assessing carcass traits, growth, feed efficiency and health factors in lambs produced from mating six rams to 100 ewes. The rams were the top performers in a 60-day test conducted in the summer of 2003 at the University of Wyoming and co-sponsored by the Wyoming Wool Growers Association and Mountain States Lamb Cooperative. The study will also gauge methods to identify progeny lambs using retinal imaging technology along with electronic identification.