The Comparison of Weight and Shape-related Traits in Eggs from Different Chicken Genotypes

Although there are intensively selected lines and non-selected standard breeds in terms of production characteristics in the chickens, there is limited information on the comparing their egg shape-related traits. This study aimed to compare using the parameters of weight, width, length, shape index-L/W (Length/Width), and shape index-W/L of egg in some meat-type (Anadolu-T, Ross 308, Dam Line and Sire Line), egg-type (Atak-S, Lohmann Brown and Lohmann Selected Leghorn), and standard breeds (Sultan and Ameraucana). The data from 2476 eggs from 9 genotypes obtained from 50-55 weeks hens and classified under 3 main types were analyzed with univariate and multivariate methods. The mean egg weights of Sire Line, Ross 308, Anadolu-T, Lohmann Brown, Atak-S, Dam Line, Lohmann Selected Leghorn, Sultan and Ameraucana genotypes were 69.89f, 69.10f, 62.84e, 59.59d, 59.58d, 59.51d, 56.81c, 45.87b and 43.03a g, respectively (P<0.05). In the same order, the mean egg width was determined as 44.72f, 45.61g, 43.41de, 43.32de, 43.62e, 43.17d, 42.46c, 39.90b and 39.17a mm (P<0.05). The mean egg length was found to be 61.97g, 58.80e, 59.72f, 56.12bc, 57.58d, 56.59c, 56.00b, 51.30a and 51.47a mm (P<0.05). The egg shape index-W/L and egg shape index-L/W was calculated to be 74.78a, 76.50b, 77.55c % and 138.67c, 128.99a, 137.59c, 129.45a, 132.16b, 131.12b, 131.93b, 128.68a, 131.47b %, respectively (P<0.05). The egg weights of meat-type, egg-type, and standard breeds were 64.61c, 58.36b, and 45.42a g, respectively (P<0.01). The egg width was found to be 44.06c, 42.97b and 39.78a mm (P<0.05). The egg length was 59.05c, 56.20b, and 51.35a mm (P<0.05). We also detected significant positive correlations (P<0.01) between the egg weight and the egg width (r=0.88), and the egg length (r=0.83). In the discriminant analyses, the success of assigning eggs to their groups was relatively low (52.4%) in terms of genotypes, but high (78.1%) in the type groups. The significant changes in the egg weight and shape-related traits were determined according to chicken genotypes and types. It was observed that intensive selection in chickens, especially in egg-type genotypes, had a strong effect on egg weight and shape-related traits.