Variation in Egg Quality Traits among Indigenous Chicken Ecotypes of Uganda

Abstract

Chicken eggs provide affordable, high-quality animal protein. Understanding egg quality traits is essential since they influence grading, pricing, chick weight and consumer preferences. This study examined egg quality variations among ecotypes from hens selectively bred for egg production and mature body weight. Birds had ad libitum access to a uniform layer diet, and daily egg collections allowed for detailed analyses of external and internal egg traits. Results revealed significant ecotype-based variation in external egg traits, with Apac hens laying the heaviest and longest eggs, while Gulu hens produced the lightest. Lira eggs had the highest shape index (SI), while Gulu’s was lowest. Among eggshell characteristics, Gulu eggs had the thickest shells, while Katakwi eggs had the heaviest shells, shell index, and shell ratio. Internal egg traits, including yolk depth, yolk ratio, and yolk index, differed significantly across ecotypes, with Katakwi eggs having the highest values. Yolk colour was also variable, with Gulu eggs scoring highest and Lira eggs lowest. Significant differences (p<0.01) in albumen traits were observed; Apac and Lira eggs had the highest albumen depth, weight, and Haugh unit (HU) scores, with Katakwi eggs scoring the lowest. Egg weight positively correlated with length, shell and albumen weight, yolk depth, and Haugh unit but negatively with yolk ratio. Overall, these findings highlight ecotype-based quality differences suitable for selective breeding for egg weight to enhance egg quality in Uganda's IC without destructive testing.