Effects of source and level of in ovo-injected vitamin D3 on the hatchability and serum 25-hydroxycholecalciferol concentrations of Ross 708 broilers.

Effects of the in ovo injection of vitamin D3 (D3) and 25-hydroxycholecalciferol (25OHD3) on broiler embryo serum 25OHD3 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 D3, 0.6 µg 25OHD3, 0.6 µg D3 + 0.6 µg 25OHD3, 1.2 µg D3, 1.2 µg 25OHD3, 1.2 µg D3 + 1.2 µg 25OHD3, 2.4 µg D3, 2.4 µg 25OHD3, or 2.4 µg D3 + 2.4 µg 25OHD3. At 432 h of incubation (hoi), 50-µL solution volumes were injected. Blood samples were collected at 462 hoi for serum 25OHD3 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 D3 source alone or in combination had higher serum 25OHD3 concentrations than those that were injected with diluent alone or diluent containing 0.6 µg of D3. Hatchlings that received 1.2 or 2.4 µg of 25OHD3 had higher percentage of yolk dry matter or lower percentage of yolk moisture levels than noninjected controls and those that received D3 alone at any level. These results indicate that the in ovo injection of either vitamin D3 source at levels equal to or higher than 1.2 µg resulted in serum 25OHD3 concentrations that were higher than that of noninjected controls. In addition, the in ovo injection of 1.2 µg or higher of either vitamin D3 source did not negatively affect broiler HI or chick quality.

Effects of in ovo injection of L-ascorbic acid on growth performance, carcass composition, plasma antioxidant capacity, and meat quality in broiler chickens1,2,3.

The current study was designed to investigate the effects of the in ovo injection of different dosages of L-ascorbic acid (AA) on posthatch growth performance, carcass characteristics, plasma antioxidant capacity, and meat quality in broiler chickens. A total of 2,220 Ross 708 broiler hatching eggs containing live embryos at 17 D of incubation were subjected to 1 of 6 treatments (trt): non-injected control, saline-injected control, or saline containing 3, 6, 12 or 36 mg of AA. An Inovoject m semi-automatic multi-egg injector was used to inject a 100 µL volume of sterile saline (0.85%) alone or containing the different AA dosage into each egg. After hatch, 14 male hatchlings from each trt group were randomly selected and placed in each of 10 replicate floor pens for growth performance evaluation through 45 D posthatch. Chicks from the 3 and 6 mg AA trt groups had a higher average daily BW gain and a higher feed intake compared to the saline-injected control group during the grower phase. Chicks in the 12 mg AA trt group exhibited a better feed efficiency in the late finisher phase and the entire growing phase than those in the saline-injected control group. Higher thigh and leg percentages were observed in chicks from the 3 and 6 mg AA trt groups than in the non-injected control group. Compared to the non-injected or saline-injected control groups, birds in the 12 mg AA trt group were observed to have a lower plasma malondialdehyde content during the grower and finisher phases, and breast muscle tenderness was elevated in chicks from the 36 mg AA trt group. Taken together, these results suggest that the in ovo injection of AA (3 to 12 mg per egg) have lasting positive effects on the posthatch growth, leg muscle development, and systemic antioxidant capacity of broilers. Higher injected dosages of AA (36 mg per egg) may also have the potential to improve broiler meat quality.

Effects of in ovo administration of L-ascorbic acid on broiler hatchability and its influence on the effects of pre-placement holding time on broiler quality characteristics,.

The current study was conducted to determine the possible effects of the in ovo administration of different dosages of L-ascorbic acid (AA) to broiler hatching eggs on hatchability and its potential for reducing the adverse effects of delayed placement.A total of 702 broiler hatching eggs was hand-injected at 17 d of incubation (DOI) with 100 µL of sterile saline (0.85%) alone or containing 0.5, 1.5, 4.5, or 13.5 mg AA. Hatchability was recorded every 5 h from 480 h to 505 hours. Results showed that AA injection did not affect embryo BW as percentage of set egg weight or yolk sac weight as percentage of embryo weight at 19.5 DOI. The hatching time of all embryos that received an AA in ovo injection was between 480 and 495 h of incubation, and significantly fewer embryos hatched before 480 h in comparison to non-injected controls. Hatchability (above 92% in all groups) was not significantly affected by injection treatment. However, fertile eggs injected with saline containing 4.5 mg AA had the highest hatchability. At 21 DOI, hatching BW as a percentage of set egg weight and yolk sac weight as a percentage of BW were numerically higher in AA injection groups. An in ovo injection of AA at a 13.5 mg/egg level resulted in a numerically higher BW as a percentage of set egg weight. The in ovo injection of AA did not reduce the adverse effects of a 48-hour posthatch pre-placement holding time on BW or on yolk sac absorption. Overall, in ovo injection of L-ascorbic acid (0.5 to 13.5 mg/egg) into fertile broiler hatching eggs at 17 DOI did not negatively affect hatchability or embryo development, and did not prevent the negative effects of a 48-hour posthatch holding time on BW and yolk sac absorption. The range of tolerance as well as the optimal dosage of in ovo-injected AA warrants future study.