Scienceline Publications Journal of World's Poultry Research 2322-455X 11 3 2021 September Effects of Broiler Breeders’ Age on Egg Quality Characteristics and Their Correlation Coefficients 368 375 https://jwpr.science-line.com/attachments/article/59/JWPR%2011(3)%20368-375,%202021.pdf EN Freddy Manyeula Department of Animal Science, Botswana University of Agriculture and Natural Resources, Private Bag 0027, Sebele, Gaborone, Botswana Boingotlo Sebolai ccDepartment of Biometry and Mathematics, Faculty of Sciences, Botswana University of Agriculture and Natural Resources, Private Bag 0027, Sebele, Gaborone, Botswana Godiraone Sempule Department of Animal Science, Botswana University of Agriculture and Natural Resources, Private Bag 0027, Sebele, Gaborone, Botswana John Cassius Moreki Department of Animal Science, Botswana University of Agriculture and Natural Resources, Private Bag 0027, Sebele, Gaborone, Botswana The current study was designed to assess the effect of Ross breeder hens’ age on the egg qualities and their correlations. The external and internal qualities of eggs were compared, and their correlation coefficients as influenced by the age of breeder hens were determined. A sample of 300 Ross breeder hen eggs was obtained from the Ross breeder farm with 100 eggs drawn from each laying period of ages, namely 30, 45, and 60 weeks. Measured parameters included egg weight, egg length, egg width, shell weight, and shell thickness. Data were evaluated for linear and quadratic effects using polynomial contrasts. Response surface regression analysis was applied to describe the responses of egg quality to the aging of breeder hens. The results showed that egg weight, egg length, egg width, shell weight, egg yolk, egg content, egg volume, shell percentage, albumen weight, egg shape index, and egg surface area increased over time. Haugh unit and thick albumen indicated that the eggs in all age groups were fresh and had high quality. Shell thickness was constant in all age groups. Egg weight was significantly correlated with egg length, width, yolk (length, width, weight, and height), and shell weight. In conclusion, the egg quality improved as the hens' age increased implying that age is an effective factor in improving the quality of eggs. Age Broiler breeder Egg quality Shell quality