Effect of the level of cholecalciferol supplementation in broiler diets

What is it about?

A study was conducted to evaluate four different cholecalciferol levels (NRC; modified), using diets supplemented with 200 (control), 1500, 2500 or 3500 IU/kg of cholecalciferol (VIT-D3). At both 21 and 42 days, the BW of birds fed 1500 IU/kg to 3500 IU/kg of VIT-D3 was significantly greater than birds fed 200 IU/kg. Similarly, better FCR was observed in birds those fed diets of high level of VIT-D3. Better dressing percentage and breast meat yield were noted in birds fed diets containing 2500 or 3500 IU/kg VIT-D3. Both tibia and toe ash contents were increased progressively with increased concentrations of cholecalciferol in feed. The incidence of TD (percentage of birds having TD scores greater than zero) was significantly influenced by level of 3500 IU VIT-D3/kg at 42 days. The severity of TD in birds fed diets containing 200 IU/kg VIT-D3 was apparently higher than birds fed diets with higher levels of VIT-D3. Concentrations of calcium and phosphorus minerals in the serum increased progressively with the high level of VIT-D3 supplementation to birds at both 21 and 42 days of age. Feeding levels of 1500 or 3500 IU of vitamin D3 did positively affect the immune system within the parameters measured.

Featured Image

Why is it important?

According to an industry survey of commercial broiler producers, the average level of vitamin D supplementation in broiler starter diets in the US commercial poultry industry was 2819 IU/kg with the low 25% of producers adding 1988 IU/kg and the top 25% of producers adding 4030 IU/kg. As a means of reducing disease problem in broiler, we have to suggest a modified feeding programme with high levels of vitamin D3 supplementation than NRC (1994) requirements to allow for adequate skeletal growth in the starter and finisher diets. This modified feeding programme may have to reduce the disease problem and maintain livability and tibia ash at high dietary levels of vitamin D3. Vitamin D3 supplementation effects on carcass yield in steer have been studied, but information on the effects of the dose of vitamin D3 on broiler breast meat yield is yet scarcity. The effects of vitamin D on the immune system have been explored in murine systems, but there is a paucity of literature concerning the effects of vitamin D on the avian immune system.

Perspectives