Heritability estimates of components of incubation mortality in white leghorns

Abstract

1. A total of 39,280 eggs obtained from two selected White Leghorn strains over 4 generations representing 290 sires were incubated.

2. The unhatched eggs were broken open for examination of embryonic developments and classified as early‐dead (0–11 d), late‐dead (12–22 d) and pips.

3. The sire‐component heritability estimates (%) pooled over years in the two strains, respectively were 8.5 ±1.5 and 7.6 ±1.4 for total mortality; 0.5 ± 0.5 and 6.3 ± 1.2 for early‐dead; 5.8 ±1.2 and 5.5 ± 1.1 for late‐dead and 5.0 ± 1.1 and 3.1 ± 0.9 for pips.