The present work was carried out to study the effect of ascorbic acid (AsA) injection into fertile Hy-line layer eggs on hatchability, mortality and some blood and hematological parameters of hatched chicks. Three hundred Hy-line layer eggs were divided into four equal groups with 75 eggs for each group with three replicate (25 fertile eggs for each replicate). The first group was injected, pre-incubation, in the air cell by 50 μl deionized water and served as a sham control. While the second, third and fourth groups were injected in the air cell with either 2, 4 or 6 % ascorbic acid. dissolved in 50 μl deionized water and served as AsA-treated groups.
Eggs were incubated at 37.5°C and 60 % relative humidity during the first 19th days of incubation. Eggs were turned automatically every 2 hour until the 19th day. At the 10th day of incubation, eggs were examined by light candling to remove infertile eggs . All eggs were transferred to the hatchery at the end of the 19th day of incubation, and placed in hatching trays at 37°C temperature and 70-75 % relative humidity until hatching.
hatchability rate, hatching and hatched chick's body weight unlike mortality were significantly higher in the 6 % AsA groups than all the AsA groups or the control group. Hemoglobin concentration was significantly (p<0.05) higher in the the 4 % AsA group and the 6 % AsA group (p<0.05) as compared to the 2 % AsA or control groups. However there was no significant difference in the cholesterol concentration between the control group and all the AsA groups. Glucose and triiodothyronin concentrations were significantly (p<0.05) higher in the 6 % AsA group than the 2 % AsA or control groups. In conclusion, our study suggests injecting 50 microliters of 6 % ascorbic acid reduced embryonic mortality and improvd hatchability and hatched chicks'body weight.