Fig. 1

Laiwu Black chickens are a dual-purpose breed for both egg-laying and meat production. The average bodyweight of 8-week-old roosters is 581 g, while the average weight of hens is 512 g. The onset of laying occurs at approximately 145 days, with an average bodyweight of 1,848 g for roosters and 1,399 g for hens. The annual egg production is around 175 eggs