Roles of the sire and dam quail in egg, yolk, albumen, and shell weight alterations due to the parthenogenetic trait

Infertile eggs from Chinese Painted quail exhibit parthenogenesis, and the 1st egg in a clutch sequence is more likely to develop a parthenogenetic embryo. Also, hens that exhibit parthenogenesis have shorter clutches and heavier egg weights. These larger eggs may be a result of the egg residing in the oviduct longer, allowing more time for the parthenote to develop. However, it is unknown which components of the egg are altered due to the parthenogenetic trait or the role of dams and sires from the parthenogenetic line of quails in these alterations. Therefore, our objective was to determine if the parthenogenetic trait in dams, sires, or both contributes to alterations in egg components, such as yolk, albumen, and shell weights. Two selected lines of quail, 1 line selected for parthenogenesis and 1 line that was unselected for the parthenogenetic trait (control), were utilized in a 2 x 2 factorial arrangement of dam and sire lines to create 4 breeding treatments: control dams + control sires (CC), control dams + parthenogenetic sires (CP), parthenogenetic dams + control sires (PC), parthenogenetic dams + parthenogenetic sires (PP). Daily, fresh eggs were collected, labeled, weighed, and the germinal disc was classified as fertile, unfertilized without development, or parthenote. Yolk, albumen, and shell weights were obtained, and their weights were also calculated as percentage of total egg weight. A dam main effect revealed heavier weights for total egg, yolk, albumen, and shell as well as a larger percentage of albumen and ratio of albumen to yolk in parthenogenetic line dams versus control line dams. However, the percentage of yolk was higher for control than parthenogenetic line dams. The increase in total egg and egg component weights due to the parthenogenetic trait suggests that the transit time of the egg through the oviduct is altered. Perhaps transit through the magnum and uterus is delayed the most yielding greater albumen and shell weights, respectively.