Egg quality and egg albumen property of domestic chicken, duck, goose, turkey, quail, and pigeon

Poultry eggs from different species varied significantly, due to their divergent process of evolution. However, the information on egg characteristics has been limited mostly to chicken. The current study compared the egg quality, albumen physical and nutritional property for domesticated chicken, duck, goose, turkey, quail, and pigeon. Egg quality traits among different species differed significantly, such as egg weight (from 11 to 139 g), egg shape (from 1.28 to 1.44), proportion of yolk (from 19.3 to 37.9%), and breaking strength (from 0.91 to 8.04 kg/cm(2)). For the physical property of albumen gel, pigeon egg was the most special one. The albumen gel of pigeon egg had a transparent appearance (A = 1.23), and it had the highest hardness (121.7 g) and water-holding capacity (96%) but a medium level of total cutting work (440 g.s). Hence, it was easy for deformation but was hard to cut off when external force was applied. For nutritional compositions of egg albumen, goose egg had the highest moisture (89.21%) and lowest crude protein (8.5%) contents. Specific to amino acid, glutamic acid was found the most abundant in albumen of all six species. Egg albumen of turkey had the highest quantity of essential amino acids (EAA) and total amino acids (TAA), while duck and goose had relatively higher EAA/TAA ratios. Both PCA and cluster analysis revealed the high similarity of amino acid composition between duck and goose, and among quail, turkey, and chicken. The comparative data will improve the understanding of egg qualities of major poultry species and can be helpful in technological application of egg albumen.