Improvement of egg quality in the native Marandi chicken breed through crossbreeding with White Leghorn

This study aimed to enhance the egg quality of native Iranian chickens through a crossbreeding program using White Leghorn (WL) as the dam line and Marandi (MA) as the parental line to produce crossbred offspring (MA × WL). Various egg quality parameters were assessed during the experiment. Significant differences were observed in egg quality traits between WL and MA, with WL demonstrating superior performance in most traits (except shell percentage and egg shape index) compared to MA ( P < 0.05). Notably, the MA × WL exhibited significantly improved performance in most studied traits compared to MA. Negative heterosis was observed for albumen height and Haugh unit, which showed similar values in MA and MA × WL. Furthermore, MA × WL resembled WL more closely than MA in terms of egg dimensions, shell weight, and yolk weight ( P < 0.05). Overall, this study suggests that crossbreeding can enhance the egg quality of native chickens by leveraging the expression of relevant WL genes in the crossbreds. Additionally, the adaptability of MA to local environmental conditions may be partially inherited by MA × WL, warranting further investigation in subsequent studies.