Silicon supplementation affects mineral metabolism but not bone density or strength in male broilers

Because leg injuries produce welfare concerns and impact production for broilers, numerous interventions have been suggested as potential solutions. One mineral which may affect bone quality is silicon. The objective of this study was to determine if supplementing bioavailable silicon could affect bone morphology, mineralization, and strength without negatively influencing welfare and meat quality. Male broilers were raised from d 1 after hatching until 42 d of age and randomly assigned to treatment groups for silicon supplementation in water: Control (no supplement, C; n = 125), Normal (0.011 ml supplement/kg bodyweight, N; n = 125) and High (0.063 ml supplement/kg bodyweight, H; n = 125). Toe damage, footpad dermatitis, hock burn, and keel blisters were assessed on d 42. Blood samples were collected from wing veins for serum osteocalcin, pyridinoline cross-links, and mineral analysis. Clinical QCT scans and analysis were conducted immediately before four-point bending tests of tibias. Texture analysis was performed on cooked fillets. Silicon supplementation tended to increase daily water consumption in N and H as compared to C (P = 0.07). Footpad dermatitis and hock burn scores were higher in H than in N or C (P < 0.05 for both comparisons). Supplementation altered serum minerals (P < 0.001), but bone density, morphology, and strength measures were similar among groups. The highest level of supplementation in the current study on a kg bodyweight basis was above recommended intakes but below previous amounts demonstrating silicon's positive influence on bone, indicating that previously suggested minimum thresholds need to be reevaluated. Factors such as growth rate and mechanical loading likely play a greater role in developing bone quality than trying to supplement on top of good basic nutrition alone.