Effect of Genetic and Non-genetic Parameters on Growth and Production Traits in Punjab Brown, PB1 and PB2 Lines

Abstract

The present study was undertaken during (August, 2023–January, 2025) at the Poultry Research Farm, Directorate of Livestock Farms, Guru Angad Dev Veterinary and Animal Sciences University (GADVASU), Ludhiana, Punjab, India, to evaluate the genetic performance of three dual-purpose chicken lines, PB1, PB2 and Punjab Brown, with respect to growth and reproduction traits to support future selection and breeding programmes. A total of 1328 birds comprising PB1 (n=549), PB2 (n=490) and Punjab Brown (n=289) were maintained under standard management conditions and evaluated from 5 to 52 weeks of age. Body weights were recorded at 5, 20 and 40 weeks, while reproductive traits included age at sexual maturity (ASM), egg number up to 40 weeks (EN40) and egg weight at 40 and 52 weeks (EW40, EW52). Variance components were estimated using REML under a multi-trait animal model, including hatch and sex as fixed effects. Significant differences (p≤0.01) were observed among the lines for growth traits, with PB1 showing the highest mean body weights followed by PB2 and Punjab Brown. Heritability estimates for body weight traits were moderate to high (0.28–0.55), indicating good scope for genetic improvement, while egg production traits exhibited low heritability (<0.20). It was concluded that PB1 and PB2 possessed strong genetic potential for growth improvement, whereas Punjab Brown remained valuable for adaptability. Selection during early growth stages was recommended to maximize genetic gains, while reproductive traits might require integration of genetic selection with improved management.