Evaluating different bone processing methods used in assessing mineralization in broilers

SUMMARY: The study determined the effect of bone processing method on broiler tibia ash content. First, a total of 288-day-old, Ross 308 male broilers were fed from hatch for 35 d on 1 of 6 diets differing in P level (8 pens of 6 chicks/treatment). Tibias of 2 birds/pen were used to determine the effect of Soxhlet fat extraction (left tibias) and cartilage caps exclusion (right tibias) on ash content (trial 1). Second, to examine the effect of duration of Soxhlet extraction on fat extraction efficiency, 264-day-old Ross 308 male broilers were allocated to 33 pens with 8 birds each (trial 2) and all birds were fed a standard broiler diet. On d 42 of trial 2, 1 bird per pen was sampled and right tibia bones were collected. In a final trial, 384 one-day Hubbard JA787 male chicks were distributed to 3 treatments differing in energy and protein density (16 pens/treatment and 8 birds/pen) (trial 3). At d 42 of trial 3, 2 birds/pen were sampled, and tibias were used to determine the effect of autoclaving before flesh removal on ash content. The statistical residuals were used to express the accuracy of ash measurement. Autoclaving and cartilage cap inclusion significantly increased ash content. Fat extraction significantly improved the accuracy of ash determination. The fat extracted from tibias was significantly increasing up to 6 h only. Cartilage inclusion and autoclaving did not significantly alter ash determination accuracy. Autoclaving to ease flesh removal followed by a 5.76-h fat extraction is recommended before bone ashing for ash determination. Details of bone processing before ash determination should be stated to allow for comparison of the results of unrelated studies.