1. Ammonia is a toxic gas and an air pollutant of great concern. The effects of ammonia-induced damage in ducks are rarely reported.

2. A total of 176 laying ducks were randomly allocated to one of two groups with four replicates and were exposed to ammonia at 5 ± 5 ppm (low ammonia, LA) or 75 ± 5 ppm (high ammonia, HA), respectively, for 30 days.

3. The results showed that atmospheric ammonia exposure significantly decreased body weight and laying performance (P < 0.05). It significantly changed serum biochemical indices by increasing alanine aminotransferase and aspartate aminotransferase (P < 0.05), and decreasing superoxide dismutase activity (P < 0.05). Haematoxylin and eosin staining of hepatocytes revealed severe fatty degeneration. Results of RNA-seq analyses revealed that eight genes were significantly up-regulated in the HA group, which were involved in catalytic activity, single-organism metabolic processes, oxidation-reduction processes, and carbohydrate metabolic processes.

4. These results indicated that atmospheric ammonia exposure reduced production performance, affected serum biochemical indices, and led to severe fatty degeneration in the liver of laying ducks. Differentially expressed genes in liver indicated that there were effects of ammonia exposure on the metabolism and detoxification capabilities in ducks.

1. 氨是一种有毒气体，是一种备受关注的空气污染物。氨对鸭子造成损害的影响很少见报道。

2. 总共 176 只蛋鸭被随机分配到两组中的一组，重复四次，分别暴露于 5 ± 5 ppm（低氨，LA）或 75 ± 5 ppm（高氨，HA）的氨中，用于30天。

3.结果表明，大气氨暴露显着降低体重和产蛋性能（P < 0.05）。它通过增加丙氨酸氨基转移酶和天冬氨酸氨基转移酶（P < 0.05）和降低超氧化物歧化酶活性（P < 0.05）显着改变血清生化指标。肝细胞的苏木精和伊红染色显示严重的脂肪变性。RNA-seq分析结果显示，HA组中有8个基因显着上调，涉及催化活性、单一生物体代谢过程、氧化还原过程和碳水化合物代谢过程。

4. 这些结果表明，大气中的氨暴露会降低生产性能，影响血清生化指标，并导致蛋鸭肝脏出现严重的脂肪变性。肝脏中差异表达的基因表明氨暴露对鸭的代谢和解毒能力有影响。