Effects of Light Stimulation Age on Body Weight and Egg Production Traits of Broiler Pure-Lines in the Laying Period

Abstract

In this study, the effects of light stimulation at normal (NLS: 154 days) and early (ELS: 140 days)age on some physiological and reproductive traits in dam and sire broiler pure-lines were carriedout during the laying period. The study was conducted with A1, A2, A3, A4 dam lines and B1, B2sire lines up to 43 weeks of age, whose breeding studies were carried out in Eskişehir Geçit KuşağıAgricultural Research Institute. Live weight and feed consumption were determined during thegrowing period. In the laying period, in addition to these, the first laying age, 50% yield age, eggyield, hatching egg yield and egg weight were determined. The data obtained were evaluatedaccording to light stimulation age and pure-lines by two factor analysis of variance. NLS and ELStreatments did not significantly affect the body weights of the pure-lines at 20, 24 and 43 weeks ofage. However, differences were found significant in terms of body weight at 20, 24 and 43 weeksof age in pure-lines. Lines reached the first laying age at 172 days in NLS, and at 165 days of agein ELS. The 50% yield age was realized at 184 d and 176 d of age in parallel with the first layingage. The effects of light stimulation age on egg yield and hatching egg yield were found significant.In NLS treatment all pure-lines, 5 more eggs were produced in egg yield and hatching egg yield.However, differences in egg yield and weight in pure-lines were found significant. The study resultsshowed that the egg production can be increased by first light stimulation at the 20 weeks of age,provided that at least 2 kg live weight is achieved in broiler pure-lines.