Abstract: This study aimed to investigate the effect of forced moulting on productive performance and egg quality of laying hens. A total of 4 500 Hy-line brown laying hens aged 80 weeks were selected and divided into A, B and C groups with 1 500 individuals in each group, which were raised in the experimental group areaⅠ; a total of 3 000 60-week-old Hy-line brown laying hens were selected and divided into D and E groups with 1 500 individuals in each group, which were raised in the experimental group area Ⅱ; another 1 500 60-week-old Hy-line brown laying hens （group F） were selected and raised in the control group area Ⅲ. The experimental group areasⅠand Ⅱ were located in the same hen house, and the control group area Ⅲ was located in another hen house. By controlling feed, drinking water supply and lighting, hens of groups A-E were forced to moulting, while those of group F did not received the forced moulting treatment. This study included a 7-day pre-trial period and a 56-day formal-trial period. During the formal-trial period, the egg production rate, egg quality indicators, and mortality of each group of laying hens were determined. The results showed that the average egg production rate of groups A, B and C was increased by 27.1% after forced moulting, and the average egg production rate of groups D and E was increased by 16.1% after forced moulting, and the average egg production rate of group F was decreased by 5.5%; the egg weight, eggshell strength, protein height, egg shape index, and thickness of eggshell tip of the 5 experimental groups （groups A-E） were increased by 2.5%, 11.8%, 8.8%, 3.3% and 14.8% respectively compared with the control group （group F）; the average mortality rate of the 5 experimental groups （groups A - E） was 2.5%, and that of the control group （group F） was 1.5%. In summary, the application of forced moulting technique can significantly increase the egg production rate of Hy-line brown laying hens and improve their egg qualities.

Key words: forced molting, laying hens, production performance, egg quality