Selection indices for desired gain in various traits of White Leghorn hens

Data on 1136 White Leghorn hens, progenies of 58 sires and 199 dams were utilized to construct and evaluate weight free selection indices for desired gain. Four selection indices were constructed using information on age at sexual maturity, body weight at 18weeks of age, body weight at 32-weeks of age, egg production up to 40-weeks of age and egg weight at 35-weeks of age from individual, individual + half sibs, individual + full sibs, individual + half sibs + full sibs for obtaining reduction of 7 days in average age at sexual maturity and increase of 8 eggs in 40-week egg production while considering no change in other traits. The study showed that the index (I_D1) including all the five traits and using information only on individual performance would bring about the desired response in 6.369 generations. Addition of half (I_D2) and full sib information (I_D3) decreased the required number of generations to 6.067 and 5.775 respectively. When all the three sources of information were combined to form index I_D4, the number of generations required to obtain the similar gains in age at sexual maturity and egg production reduced to a minimum of 5.756. Hence, inclusion of information from other relatives (sibs) in addition to individual performance is important for obtaining faster genetic gains.