Effect of in ovo injection of vitamin C during incubation on hatchability of chickens and ducks.

The aim of the investigation was to ascertain the influence of different doses of vitamin C injected at selected dates of incubation into the eggs of broiler breeders and Pekin ducks on hatchability. The injected vitamin C doses were administered into the air cell on the 13th, 15th and 17th days (3 and 6 mg--chickens) and on the 12th and 20th days (4 and 8 mg--ducks) of incubation. In the case of chickens, no significant differences were recorded between the control and experimental groups with regard to hatchability, although the highest value of hatchability from fertilized eggs was determined in the group injected with 6 mg of vitamin C on the 15th day of incubation. On the other hand, in ducks, significant differences were found between the control and experimental groups (4 mg of vitamin C administered on days 12 and 20 and 8 mg of vitamin C injected on day 20 of incubation) regarding hatchability. The value of this trait was higher in the group of eggs injected with ascorbic acid in comparison with the eggs which were not treated. On average, the difference amounted to 32.5 percentage points. Similarly, in the case of the number of dead embryos and unhatched chicks, better results were observed in the above-mentioned experimental groups. In summary, vitamin C injected into chicken eggs failed to influence hatchability. In the case of duck eggs, it was demonstrated that their injection on the 20th day of incubation with selected doses of vitamin C (4 and 8 mg/egg) improved hatchability by decreasing the proportions of dead and unhatched embryos.