1. Optical methods won't work, since chickens fluff. 2. Submersion in water won't work (see (1)). The best approach is a load-cell based chute with steps (a la Milliken oil-drop experiment): 1. Herd the birds into a chute which contains a load-cell-instrumented platform. 2. Capture weights from platform. 3. Assume weight is an integral multiple of bird weight, and birds are relatively uniform in weight. 4. Calculate bird weight distribution and average from measurements taken at intervals until all chickens have passed. 5. The herding chute can feed back into the house, so it's endless loop. Another practical idea: 1. Keep track of all feed consumed at intervals. 2. Keep track of number of birds at intervals. 3. Calculate mean bird weight based on cumulative feed consumed/bird. 4. Calibrate by manual weighings. (This is the traditional method of determining marketability in the poultry industry. Ratio of weight/feed efficiency is an important operating characteristic to optimize. This method not only meets original requirement but also will allow optimization of profitability.) ================================================================ Robert A. LaBudde, PhD, PAS, Dpl. ACAFS e-mail: ral@lcfltd.com Least Cost Formulations, Ltd. URL: http://lcfltd.com/ 824 Timberlake Drive Tel: 757-467-0954 Virginia Beach, VA 23464-3239 Fax: 757-467-2947 "Vere scire est per causae scire" ================================================================