Genetic evaluation for growth performance in Japanese quail line selected for fast growth rate across eight generations

Abstract The world is suffering from a protein shortage due to population growth and increased food demand, increasing the pressure on poultry breeders to boost production. Additionally, Japanese quail (JQ), with their small size, rapid growth, short generational interval, and high egg production, offer a promising solution to address this challenge. A ten-generation study conducted at Fayoum University Poultry Research Center involved 17,806 JQ chicks, which were divided into two lines: one was selected for fast growth rate from 1-21 days (FGR1-21), and the other line was the control line (CL). It aimed to investigate the consequences of selection, evaluate selection effectiveness for increased early growth rate (GR1-21). All studied growth traits were significantly influenced by generation, line, and sex effects, except for body weight at hatch (BW1) and GR1-21, where sex had an insignificant effect. The interaction effect between generation and line significantly affected all studied traits, favoring the FGR1-21 line in the 8th selected generation. The cumulative response based on two different methods was in the desired direction for all studied growth traits, except for BW1. This was based on breeding values. The GR1-21 was found to be positively correlated, either genetically or phenotypically, with all correlated traits except for BW1. All studied growth traits had moderate heritability (h 2 ) estimates ranging from 0.18 to 0.32. It can be concluded that continuous selection for high growth rate has resulted in a well-established paternal line of JQ specialized in meat production, which can be proposed as a sustainable solution to address food security problems.