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Effect of Egg Weight and Maternal Flock Age on egg characteristics, incubation traits, and offspring performance

Filipe Moreno, Fabiano Dahlke, Leandro Kuritza , Marcus Vinícius Alvarez, Isabella Dias , Alex Maiorka

Abstract

Context. There are pre-hatch factors that can influence performance during the growing phase, such as the age of the broiler breeder and the egg weight. Aims. Investigate the effects of flock age and egg weight, independent of each other, on egg characteristics, incubation traits, hatchling weight, and initial offspring performance. Methods. Treatments consisted of eggs laid by 28- (Y), 42- (M), or 61-week-old (O) broiler breeder hens and different egg weight classes, light - L (56.6-62.2g), average - A (62.3-67.9g), or heavy – H (68-73.6g). It was selected eggs with similar weights from different hens' ages (treatments YA/ML, YH/MA/OL, and MA/OA), which allowed to evaluate specifically the effect of broiler breeder ages on variables: egg characteristics (eggshell, albumen, and yolk), incubation traits (egg weight loss and hatchability), hatchling weight, and the live performance of the progeny (7, 14, and 21 days). Data were submitted to one-way analysis of variance when significant means were compared by Tukey test. Key Results. Eggshell thickness and albumen height were lower, but albumen weight, yolk weight, and percentage of yolk were higher in eggs laid by older broiler breeders. When eggs of the same weight were evaluated, the variables were also affected by flock ages. Egg weight loss increases with the increasing hens age (P ≤ 0.05). The age of the hens and egg size had significant effects on hatchability and hatchling weight (P ≤ 0.05). The maximum hatchability was recorded in hens at the age of 42 weeks (90.53%). In the Medium egg weight group (62.3-67.9g), the young flock produced the lightest chick and the old flock the worst hatchability. Broiler perforance were affected by the age of the hens and egg size. Conclusions. The eggshell thickness is major influenced by the egg size. However, other egg features are strongly influenced by flock age. Egg weight loss during incubation and chick weight are reduced in young flocks. The oldest flocks produced heavier chick and the positive effect on feed intake and body weight remains until 14 days. Implications. Flock age and egg weight can influence the egg caractheristcs and performance of broilers.

AN24148  Accepted 29 July 2024

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