Effect of vitamin D3 and strontium on performance, nutrient retention, and bone mineral composition in broiler chickens

Abstract

The therapeutic use of vitamin D3 and strontium has been successful for the treatment of osteoporosis in humans; however, the value of similar strategies in poultry is not clear. Male Ross broiler chicks (n = 216) were used in a 28-day broiler trial to assess effects of vitamin D3 and strontium supplementation on performance, nutrient retention, bone composition, and bone mass. Treatments included an industry-standard control diet and five additional diets where vitamin D3 was added at 5000, 20 000, or 35 000 IU/kg and strontium was added at 0 or 1200 mg/kg in a 3 × 2 factorial design. Broiler chickens supplemented with strontium and additional vitamin D3 did not increase bodyweight; however, there was a significant improvement in feed efficiency at medium levels of vitamin D3, and although not statistically significant, there was also an improvement in feed conversion ratio with strontium supplementation at normal vitamin D3 concentrations. Strontium supplementation at normal levels of vitamin D3 significantly (P < 0.01) increased calcium, phosphorus, sodium, potassium, and magnesium retention. A high concentration of vitamin D3 produced a significant improvement in apparent metabolisable energy, protein, and dry matter utilisation in the broiler chicken. Paradoxically, however, there was a detrimental effect of high vitamin D3 on bodyweight and feed efficiency, which was partially ameliorated by strontium supplementation. Strontium addition did not change bone mass but did change bone composition. High levels of vitamin D3 significantly (P < 0.01) reduced bone ash content and increased strontium content of bone. In conclusion, both vitamin D3 and strontium have the potential to positively influence the performance, mineral retention, and bone characteristics of broiler chicks. However, as with calcium and phosphorus, vitamin D3 and strontium interact and so more research is required with strontium on the optimum dose rate and its relationship with vitamin D3, calcium, phosphorus, and IGF-1 in broiler nutrition.