Effects of the commercial in ovo injection of 25-hydroxycholecalciferol on broiler posthatch performance and carcass characteristics.

In ovo injection of 25-hydroxycholecalciferol [25(OH)D3] has been shown to improve hatchability of injected broiler eggs. Effects of the in ovo injection of commercial diluent containing various levels of 25(OH)D3 on broiler posthatch performance and carcass characteristics were investigated in 2 trials. On each of 10 tray levels of a single-stage incubator, all treatment groups were randomly represented with each containing 21 and 40 eggs in trials 1 and 2, respectively. Treatments included noninjected and diluent-injected (100 µL commercial diluent-injected) controls, and those that received 0.15, 0.30, 0.60, or 1.20 µg of 25(OH)D3 in trial 1 and 0.20, 0.60, 1.80, or 5.4 µg of 25(OH)D3 in trial 2, in 100 µL of commercial diluent using a commercial multi-egg injector on d 18 of incubation. On d 21 of incubation, chicks from each treatment replicate group were placed in corresponding floor pens. Feed intake, BW gain, and feed conversion were determined for the weekly and cumulative 0 to 21 d age intervals in trial 1 and for the weekly and cumulative 0 to 48 d age intervals in trial 2. In trial 2, 2 birds from each sex were selected from each treatment replicate group for determination of processing carcass characteristics on d 49 posthatch. Feed intake in the 0 to 7, 7 to 14, and 14 to 21 d age intervals and BW gain in the 0 to 7 and 14 to 21 d age intervals were affected by treatment in trial 2. The in ovo injection of up to 1.20 and 0.60 µg of 25(OH)D3 in trials 1 and 2, respectively, did not affect the BW gain of birds during the 0 to 7, 7 to 14, and 14 to 21 d age intervals compared with the noninjected and diluent-injected control groups. It was concluded that the in ovo injection of up to 1.20 µg of 25(OH)D3 into the amnion has no detrimental effect on the overall posthatch performance of broilers.