Índice de Forma para Predecir el Sexo del Polluelo antes de la Incubación

Justification: identifying the in ovo sex of chicken embryos before incubation could address the ethical and animal welfare issue associated with the culling of male chicks. Objective: to determine the effectiveness of the egg shape index in predicting the sex of criollo chicken embryos. Methodology: a total of 200 eggs were incubated, and 186 chicks were sexed at the end of the period. Egg width, length, and weight were measured to estimate the shape index. Results: significant differences were found in egg measurements according to chick sex. Eggs from female chicks had a slightly greater average width (42.21 mm) than those from males (41.19 mm), while male chick eggs were longer (54.94 mm) than female chick eggs (53.37 mm). The SI was higher in female chick eggs (79.08) compared to male chick eggs (74.96), indicating a rounder shape. Male chick eggs were also heavier (56.89 g) than female chick eggs (52.71 g). Correlations showed associations between egg measurements and chick sex, and logistic regression confirmed that SI is a significant predictor of chick sex, explaining 75% of the variability. Conclusion: the SI could be a valid tool for identifying chick sex before incubation.