Embryonic mortality and anomalies of a selected (PL2) and an unselected control (PL3) of White Leghorn were recorded, through broken-open examination. The incidence of dirty eggs was very low (0.51.1%). Fertility in the two populations was high (95.4 to 97.6%) with the difference between the two lines beingnon-significant. The incidence of total embryonic mortality varied between 10.8 and 17.2%. Maximum mortality occurred during two critical periods i.e. late (18–22 d), pipping stage and the early stage (0-5d). Strain PL2 exhibited significantly higher total embryonic mortality than the unselected control line (PL3). The incidence of malpositions in all the unhatched embryos (>17d) varied between 33.3 and 54.8% with line PL2 having higher malpositions. Of the six types of malpositions recorded, type VI i.e. break above the right wing, occurred with highest frequency in both the strains. The incidence of double mal-positions was very low i.e. 5.9 and 10.3% in PL2 and PL3 respectively. Incidence of spontaneous embryonic malformations was 5.1 and 5.9% in PL2 and PL3, respectively.
Embryonic mortality, malpositions, malformation, selection, chicken
