Effects of Egg Weight Classes on Egg Characteristics, Chick Quality and Hatchery Performance in Different Layer Lines
Abstract
This study investigated the effects of different layer lines and egg weight classes on egg characteristics, chick quality traits, and hatchery performance. Four layer lines, namely BAR-1, RIR-1, BLUE, and MAROON, were evaluated at the Ankara Poultry Research Institute. A total of 960 eggs, including 240 eggs from each line, were used and classified into light, medium, and heavy weight classes according to the mean egg weight of each line. Egg weight, egg weight loss, width, length, shape index, day-18 egg weight, chick weight, chick length, chick quality, hatching time, fertility, hatch of fertile eggs, and hatchability were determined. Data were analyzed using SPSS version 26, and P<0.05 was considered statistically significant. Genotype significantly affected almost all of the investigated traits (P<0.05). The RIR-1 line had the highest initial egg weight (61.38 g), chick weight (44.02 g), chick length (17.28 cm), and chick quality score (97.54), whereas BAR-1 showed the highest fertility (97.99%), hatch of fertile eggs (92.19%), and hatchability (90.36%). In RIR-1, these values were 78.45%, 81.66%, and 64.34%, respectively. Increasing egg weight significantly increased chick weight and chick length; however, hatchability was lower in heavy eggs (75.36%) than in light eggs (86.25%). A strong positive correlation was found between egg weight and chick weight (r=0.804; P<0.01). Overall, the findings indicate that both layer genotype and egg weight play important roles in chick development and hatchery performance. Therefore, genotype-specific hatchery performance, together with an appropriate egg weight range, should be considered when selecting hatching eggs.
