Interactive effect of vitamin D and strontium on performance and bone composition in broiler chickens

There was no improvement in BWG or FCR by day 40 with higher levels of vitamin D3 and various levels of supplemental strontium however performance was negatively affected in the starter phase. Strontium supplementation in the presence of additional vitamin D3 altered tibia bone composition and reduced Na ileal digestibility. The ratio of 30:1 for calcium to sodium in bone was maintained across all treatments as did the total percentage content of calcium, sodium, strontium, potassium and magnesium at 43%. The higher level of vitamin D3 (10,000 IU/kg) with no added strontium (0 mg/kg) produced the heaviest BWG per bird by day 40 (3157 g) however it was not statistically significant. The higher level of vitamin D3 significantly increased mortality. The feeding of lower doses of strontium and vitamin D3, particularly in the starter phase, requires further investigation.