Shahid Bahonar University of Kerman and Iranian Society of Animal Science Journal of Livestock Science and Technologies 2322-3553 14 2 2026 02 01 Monitoring changes in genetic parameters for growth traits over generations of selection in local chickens in Egypt 25 30 4992 10.22103/jlst.2025.25494.1644 EN Ellham Abbas Department of Animal Production, National Research Center, Giza, Egypt Essam El-Gendy Department of Animal Production, Faculty of Agriculture, Cairo University, Giza, Egypt Amani Youssef Department of Animal Production, National Research Center, Giza, Egypt Manal Zaki El-Deen Department of Animal Production, National Research Center, Giza, Egypt Shoukry El-Tantawy Department of Animal Production, Faculty of Agriculture, Cairo University, Giza, Egypt Marwa Ahmed Department of Animal Production, National Research Center, Giza, Egypt Mostafa Helal Department of Animal Production, Faculty of Agriculture, Cairo University, Giza, Egypt Journal Article 2025 07 02 Estimating the genetic parameters for growth traits is a crucial step before designing breeding programs to enhance the productivity in local chicken breeds. The current study estimated the genetic parameters of two local chicken lines selected for meat production (Normally Feathered, CE1, and naked-neck, CE3) and tracked the changes in these parameters over three generations of selection. Heritability estimates for the hatch weight were moderate, ranging between 0.30 and 0.31. Lower estimates ranged from 0.28 to 0.33, and were obtained for BW2 and BW4, respectively. The genetic correlations were moderate to high, and varied from 0.43 (BW12 and BW18) to 0.88 (initial BW and BW2) in the seventh generation of selection. The values in the eighth generation had the same trend and varied from 0.41 (initial BW and BW18) to 0.86 (BW2 and BW4). Similar values were obtained for body weight gain (BWG) and growth rate (GR) traits, where the highest genetic correlation (0.86) was between BWG (0-6) and GR (0-6) in the seventh and ninth generations, respectively, and the lowest was 0.62 that found between BWG (6-12) and GR (12-18) in the eighth generation. However, the highest phenotypic correlation (0.71) was also obtained between BWG (0-6) and GR (0-6) in the eighth generation, and the lowest value (0.42) was obtained between BWG (6-12) and GR (12-18) in the ninth generation of selection. The results suggested that there is enough genetic variation for further improvement in body weight at the juvenile stage. https://lst.uk.ac.ir/article_4992_586514acae94abb29296ba6e57f3f8a2.pdf