Effect of translucency and eggshell color on broiler breeder egg hatchability and hatch chick weight

A successful hatch has a considerable economic impact on all poultry companies. The aim of the current study was to describe the possible effects of shell translucency (T score) and coloration lightness (L* value) on shell thickness, hatchability, and chick weight. A total of 4,320 eggs from 4 commercial Ross 708 breeder flocks (50-55-wk old) were used. Eggs were selected for T score and L* value. A 3-point subjective scoring system was used for T score (1 = low, 2 = medium, 3 = high), and an electronic colorimeter for L* value, sorting the eggs as light (avg. L* = 80.7) or dark (avg. L* = 76.0). Data were analyzed using the GLIMMIX procedure of SAS (V9.4) and Tukey's HSD test was performed to separate means, a significant difference was considered when P & LE; 0.05. Results suggest that the color of the eggshell was related to the egg weight on the day of collection (P = 0.0056) and at transfer (P = 0.0211), in both cases dark eggs were 0.6 g heavier than light eggs. Dark eggs had a 3.8% increased hatchability of egg set (P = 0.0481) and yielded 6 mm thicker shells (P = 0.0019) when compared to light eggs. Regarding translucency, egg weight at transfer was 0.8 g heavier for T score 1 eggs compared to T score 3 (P = 0.0358). The translucency score of 1 had a 6.9% higher hatchability of eggs set (P = 0.0127) and 0.7 g heavier chick weight (P = 0.0385) compared to T score 3. However, T score 1 eggs had shells 28 mm thinner than the T score 2 and 34 mm thinner than T score 3 (P < 0.0001). An interaction effect was observed for eggshell thickness, L* value, and T score, where eggs classified as light with T score 1 had thinner eggshells compared to those that were dark with T score 3 (P = 0.0292). These results suggest that eggshell translucency and coloration lightness can be good noninvasive indicators of eggshell thickness, hatchability, and chick weight in broiler breeder flocks.

Automated summary

The study investigated the effects of shell translucency and coloration lightness on shell thickness, hatchability, and chick weight. The results showed that dark eggs were heavier and had higher hatchability and thicker shells compared to light eggs. Eggs with a lower translucency score had higher hatchability and chick weight but thinner shells compared to eggs with a higher translucency score. An interaction effect was observed for eggshell thickness, lightness value, and translucency score.