Miles D M, Miller W W, Branton S L, Maslin W R, Lott B D
Poultry Research Unit, USDA-ARS, 810 Highway 12 East, MS State, MS 39762, USA.
Avian Dis. 2006 Mar;50(1):45-9. doi: 10.1637/7386-052405R.1.
In two trials, 60 male commercial broilers were placed in each of eight environmentally controlled chambers receiving 0, 25, 50, or 75 ppm aerial ammonia from 1 to 28 days. Birds exposed to 25 ppm (lower concentration) ammonia gas developed ocular abnormalities but at a slower rate when compared with birds exposed to 50 and 75 ppm (higher concentrations). Birds exposed to higher concentrations also developed more severe lesions. With little atmospheric ammonia present after 28 days of the grow-out stage, the corneas indicated signs of healing. Lymphocytes and heterophils were seen in the iris at 49 days in ammonia-exposed birds even when ammonia exposure was terminated at 28 days. The lower ammonia concentrations resulted in abnormalities that were slight when compared with those seen at the higher ammonia concentrations. As measured by the incidence of inflammatory infiltrates in the trachea, lung, and air sacs, respiratory tract tissues did not appear to be affected by any tested level of aerial ammonia. The findings in this investigation represent the first report indicating that ammonia-induced uveitis in chickens clears rapidly after exposure to ammonia ceases.
在两项试验中，60只雄性商品肉鸡被放置在八个环境控制舱中，从1日龄到28日龄分别接受0、25、50或75 ppm的空气中氨气。暴露于25 ppm（较低浓度）氨气的鸡出现眼部异常，但与暴露于50和75 ppm（较高浓度）氨气的鸡相比，其异常发展速度较慢。暴露于较高浓度氨气的鸡也出现了更严重的病变。在生长阶段28天后，大气中氨气含量很少，角膜显示出愈合迹象。即使在28日龄时停止氨气暴露，在49日龄时仍可在氨气暴露鸡的虹膜中看到淋巴细胞和异嗜性粒细胞。与较高氨气浓度下观察到的异常相比，较低氨气浓度导致的异常较轻。通过气管、肺和气囊中炎症浸润的发生率来衡量，呼吸道组织似乎未受到任何测试水平的空气中氨气的影响。本研究结果首次表明，鸡氨气诱导的葡萄膜炎在停止接触氨气后会迅速消退。
