Abstract: 【Objective】This study was conducted to investigate the influence of ammonia concentration on growth performance and meat quality of broilers.【Method】The experiment was conducted in four chambers of the State Key Laboratory of Animal Nutrition. Three hundred and twenty 21-day-old Arbor Acres broilers with similar initial body weight were divided randomly into 4 groups for different treatments, with 4 replicates in each group and 20 broilers for each replicate. Each treatment of broilers was placed in a separated, environmentally controlled chamber, and ammonia concentrations in the four chambers were metered continuously to maintain at (3±3), (25±3), (50±3) and (75±3) µL·L^-1, respectively. The broilers were net-rearing and provided ad libitum access to water and diets. The experiment lasted for three weeks. Broilers’ feed intake and health status were recorded, broilers were weighed according to replicate to get the growth performance at the age of 32 and 42 days, at the same time, three broilers were selected and slaughtered from each replicate to measure slaughter performance and meat quality.【Result】 During the age from 22 to 32 days, when ammonia concentration was at 50, 75µL·L^-1, ADG and ADFI of broilers were significantly decreased compared with the control group(P＜0.05); ammonia concentration did not significantly affect F/G of broilers(P＞0.05). During this period, ammonia concentration did not significantly affect the dressing percentage, eviscerated carcass percentage and half-eviscerated carcass percentage of broilers (P＞0.05). During the age from 33 to 42 days, compared with the control group, ADFI of broilers was significantly decreased when ammonia concentration was 25-75 µL·L^-1 (P＜0.05); ammonia concentration did not significantly affect ADG and F/G of broilers (P＞0.05). During the whole experiment period, compared with the control groups, ADG and ADFI of broilers in all three experiment group had a significantly decrease(P＜0.05), F/G of broilers was significant increased(P＜0.05); abdominal fat percentage of broilers had a trend of rising with the increase of ammonia concentration. Compared with the control group, when ammonia concentration was at 75µL·L^-1, abdominal fat percentage of broilers was significantly improved(P＜0.05); ammonia concentration did not significantly affect the breast meat pH(after 24 h),color L* value, color a* value and color b* value (P＞0.05). Compared with the control groups, drip loss rate of breast meat in all three experiment group had a significant increase (P＜0.05). 【Conclusion】These results indicate that ammonia concentration at 25µL·L^-1 in chamber can inhibit the growth performance and meat quality of broilers, and with the increase of ammonia concentration, the influence become worse, abdominal fat percentage and drip loss rate of breast meat of broilers can be significantly improved when they are under the high ammonia concentration conditions, so, by integrating the foregoing study outcomes, the author suggested that ammonia concentration in chamber should be controlled within 25µL·L^-1.

Key words: ammonia concentration, broiler, growth performance, carcass traits, meat quality