Effect of spraying Pekin duck eggs obtained from different breeder age on hatchability

Abstract

The objective of this study was to determine the effect of spraying Pekin duck eggs obtained from different breeder age on hatchability. Hatching eggs used in this study were obtained from Pekin breeder flock. A total of 560 eggs were collected at 30 and 38-wk of breeder age at the farm. Ten eggs from each breeder age group were used to determine eggshell thickness. The other eggs for determination of hatchability and embryo development were stored for 3 d at 17 degrees C and 75% relative humidity. Eggs were incubated in the same incubator and turned from 1 to 25 days of incubation once an hour. On the 4(th) d of incubation, eggs were assigned to three treatment groups: control, spraying once a day ( Group 1), and spraying twice a day ( Group 2). Each group comprised 90 eggs which have been set to one tray each. Eggs of Group 1 and 2 were taken out of the incubator once a day and two times a day, sprayed with warm water ( 25-28 degrees C) and placed back to the incubator after 20 minutes, respectively. On the 25(th) day of incubation, all eggs were transferred singly into pedigree hatching baskets. On the 28(th) day of incubation, healthy ducklings were removed and sex and weight of the chicks was recorded. Fertility, embryonic dead and hatchability were determined. Egg weight increased ( P < 0.001) and eggshell thickness decreased ( P < 0.01) with increasing breeder age. Embryonic mortality was lower and hatchability was higher in sprayed groups than in control group ( P < 0.05) in eggs from 30 wks old hens. Increasing hen age increased the ratio of duckling weight to egg weight ( P < 0.001). Spraying of eggs affected the ratio of duckling weight to egg weight ( P < 0.001). Control and Group 1 were similar in the ratio of duckling weight to egg weight. However spraying of eggs twice a day with warm water from 4 to 25 days of incubation negatively affected the ratio of duckling weight to egg weight. It was concluded that spraying of duck eggs is partly linked to breeder hen age.