Effects of vitamin D3, calcium, and phosphorus on growth and bone development of market turkeys

A study was undertaken to determine the effects of maternal and poult nutrition on poult growth and bone development through to market age. Nicholas Large White turkey hens (200) were fed diets with 300, 900, or 2700 IU vitamin D3/kg from day-old to 37 weeks of age. Male poults (649 from Hatch 1 and 555 from Hatch 2) were fed diets containing .6 or 1.2% Ca; .4 or .8% available P; and 300, 900, or 2700 IU vitamin D3/kg to 4 weeks (Hatch 1) or 2 weeks of age (Hatch 2) in a complete factorial design. All Hatch 2 poults were given a "therapeutic" diet from 2 to 4 weeks, followed by normal grower diets from 4 to 24 weeks of age. Increasing the level of vitamin D3 in the hen diet increased weight at hatching and at 2 and 4 weeks, decreased mortality from 0 to 2 weeks, and increased bone ash percent and breaking strength and decreased the severity of rickets score at 2 weeks. Increasing the levels of Ca, P, and vitamin D3 in the poult diet gave reduced mortality from 0 to 2 weeks, increased weight at 2 and 4 weeks, increased bone ash percent and breaking strength, and decreased severity of rickets score at 2 and 4 weeks. Carcass fleshing score at 24 weeks was improved with 1.2% Ca. Conformation score and percent grade A carcasses increased linearly with level of vitamin D3 in the starter diet and were also improved by increasing the vitamin D3 in the breeder diet.