Genetic evaluation and correlated response in feed efficiency traits in White Leghorn line under long term selection

Two White Leghorn lines viz. Selected (IWH) and Control (IWC) lines derived from same base population were utilized to evaluate response in feed efficiency traits due to long term selection for part period egg production (Osborne Index) for 16 years. Data on feed efficiency traits were collected from 497 pullets of IWH and 275 pullets of IWC line during 16^th generation of both the lines and were analysed. The means of feed efficiency traits viz. feed consumed per day (FC/d), feed consumed per dozen eggs (FC/dozen), feed consumed per kilo egg mass (FC/kilo) and net feed efficiency (NFE) were 94.69 g, 1.51 kg, 2.63 kg and 2.54, respectively in IWH line and corresponding values for control line were 95.63 g, 1.81 kg, 2.87 kg and 2.63. The selected line consumed significantly less feed to produce dozen eggs as well as kilo egg mass. The correlated genetic response per generation for FC/d, FC/dozen, FC/kilo and NFE were −0.06, −18.75 kg, −15.31 g and −5.56, respectively. The genetic and phenotypic correlations were positive in direction and high in magnitude among various feed efficiency traits. Feed consumed per day was positively correlated with age at sexual maturity, 20 and 40-week body weight, 40-week egg weight, egg production and egg mass at 40 weeks of age on genetic scale whereas feed consumed per dozen eggs, feed consumed per kilo egg mass and net feed efficiency were negatively correlated with the production traits.