Comparative study of two strains of chicken for broiler production. I - Fertility and hatchability related to egg weight

Abstract

During the course of this study, 1,456 eggs laid by two strains — “A ” and “B” — of chicken for meat production were classified in three egg weight groups — I (51 — 55 g), II (56 — 60 g), III (61 — 65 g) — , in order to determine fertility and hatchability. The fertility was estimated by candling on the eighteenth day of incubation.
a — Fertility
The analysis of variance of fertility showed that the difference between the two strains (A = 88.1% and B = 88.8%) was not significant. With respect the egg weight groups, higher level of fertility occurred in class II (89.3%) while in group I and III, were obtained 87.8% and 88.1%, respectively. On the other hand, the correlation demonstrated statistical significance (r = + 0,56) between fertility and individual egg weight.
b — Hatchability
Percent hatch of good chicks from fertile eggs were 93.8% and 89.3% for strains “A ” and “B” , respectively. This difference, statistically significant, indicated therefore that the strain “B” produced more “cull chicks” — 6.1% — than strain “A ” (2.7%). In relation to egg weight groups, the higher hatchability ocurred in the class III (93.7%). Aside from, it seems that group II (56 — 60 g) shows a strong tendency to produce higher hatch of “ cull chicks” (6.9%) in relation to others egg weight groups (I = 3.9% and III = 2.7%). It appears also that incubator eggs localization did not affect the hatchability.