Effects of source and level of in ovo-injected vitamin D(3) on the hatchability and serum 25-hydroxycholecalciferol concentrations of Ross 708 broilers

Effects of the in ovo injection of vitamin D(3) (D(3)) and 25-hydroxycholecalciferol (25OHD(3)) on broiler embryo serum 25OHD(3) concentrations, hatchability, and hatchling somatic characteristics were determined. Eggs from a 35-wk-old commercial Ross 708 broiler breeder flock were set in a single-stage incubator with 11 treatments represented on each of 8 incubator tray levels (blocks). Each treatment group within a flat on each tray level contained 30 eggs. Control treatments were noninjected and diluent injected. Vitamin treatments were commercial diluent containing 0.6 μg D(3), 0.6 μg 25OHD(3), 0.6 μg D(3) + 0.6 μg 25OHD(3), 1.2 μg D(3), 1.2 μg 25OHD(3), 1.2 μg D(3) + 1.2 μg 25OHD(3), 2.4 μg D(3), 2.4 μg 25OHD(3), or 2.4 μg D(3) + 2.4 μg 25OHD(3). At 432 h of incubation (hoi), 50-μL solution volumes were injected. Blood samples were collected at 462 hoi for serum 25OHD(3) analysis, and hatchability of injected live embryonated eggs (HI) was determined at 492 and 516 hoi. At 516 hoi, hatchling yolk-free BW and weights of the liver and yolk sac were determined. Percentage of yolk moisture and dry mater was calculated. At 492 and 516 hoi, HI did not differ between treatments. Embryos that received 1.2 μg or more of either vitamin D(3) source alone or in combination had higher serum 25OHD(3) concentrations than those that were injected with diluent alone or diluent containing 0.6 μg of D(3). Hatchlings that received 1.2 or 2.4 μg of 25OHD(3) had higher percentage of yolk dry matter or lower percentage of yolk moisture levels than noninjected controls and those that received D(3) alone at any level. These results indicate that the in ovo injection of either vitamin D(3) source at levels equal to or higher than 1.2 μg resulted in serum 25OHD(3) concentrations that were higher than that of noninjected controls. In addition, the in ovo injection of 1.2 μg or higher of either vitamin D(3) source did not negatively affect broiler HI or chick quality.