In Experiment I, bone biopsies were taken from the twelfth rib and third metacarpal in twenty equine cadavers for analysis of calcium, phosphorus, ash as a percentage of wet weight (AWW%) and dry, fat-free ash percentage (DFF%). The AWW%, DFF% and percent phosphorus were significantly higher in the metacarpal than in the rib. However, calcium levels were similar between the two sites. In Experiment II, ten Quarter Horse mares were equally allotted to either a control (n=5) or a treatment group (n=5) in order to study die effects of restricted movement on physical fitness. Treatment mares were restricted to 4'x8' tie stalls while control mares were kept on native prairie grass pasture. A separate evaluation of bone mineral content was performed utilizing these mares. Biopsies from the twelfth rib were taken on day 0 (left side) and then again on day 90 (right side). Percentages of ash, calcium and phosphorus did not differ between control and treatment mares. Bone biopsy techniques may prove to be a useful tool in the future for the quantitative analysis of mineral status in the horse.