The Effect of Non-Genetic Parameters on Sex Determination

Year 2025, Volume: 22 Issue: 2, 68 - 76, 28.12.2025

Elif Babacanoğlu

Abstract

From commercial, ethical and scientific perspectives, the culling of male chicks, particularly obtained from egg-laying breeders, is the most fundamental problem to be solved in the commercial poultry industry. This study aimed to determine the gender of the embryo based on characteristics of shell quality related to the weight of hatching eggs from broiler breeders. A total of 60 hatching eggs were divided into two groups: one weighing 55.50 g and the other weighing 66.50 g. The egg weight, width and length of air space, and width and length of each egg before incubation, and the water loss of the eggs during incubation was measured. At hatching, the weight of the chicks categorised by gender was measured, as well as the residual shell thickness, pore number, width and length of the pores. The difference in chick weight by gender is due to egg weight. Male and female chicks in the 66.50 EW group were heavier than those in the 55.50 EW group. Male chicks that hatched from heavier eggs were heavier than females. Male chicks hatched from thinner eggshells. Male chicks hatched from eggs with higher shape index, wider air space, smaller pore width at the pointed end and shorter pore lengths at the blunt and equatorial ends of lighter eggs. In contrast, female chicks hatched from eggs with lower shape index, higher shell thickness and wider pore width at the blunt, equatorial and pointed ends of lighter eggs, and with smaller air space width of heavier eggs. In conclusion, the gender of the embryo can be determined before or during embryo development based on various shell quality characteristics resulting from differences in egg weights obtained from broiler breeders of the same genotype and age.

Keywords

egg , egg quality , embryo , gender determination , shell quality

Ethical Statement

The study was approved by the Committee for the Ethical Care and Use of Animals of the Van Yuzuncu Yil University (Approval number: 2024/12-08)

Supporting Institution

Van Yuzuncu Yil University

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