Center for Comparative Medicine, Baylor College of Medicine, Houston, Texas;, Email:
Center for Comparative Medicine, Baylor College of Medicine, Houston, Texas.
J Am Assoc Lab Anim Sci. 2021 Jan 1;60(1):37-43. doi: 10.30802/AALAS-JAALAS-20-000051. Epub 2020 Oct 29.
Ammonia control is an important characteristic of rodent bedding materials. Among natural bedding materials, corncob bedding provides excellent ammonia control but contains estrogenic compounds and is ingested by mice. By comparison, processed cellulose bedding products are biologically inert and harbor fewer bacteria but historically have shown low absorbency or poor ammonia control. New cellulose products have been developed to address these shortcomings. Over a 2-wk period, we evaluated intracage ammonia levels in mouse IVC using 4 bedding types: shaved aspen, corncob, virgin pelleted cellulose, and refined virgin diced cellulose. Ammonia levels were measured by using 3 methods: colored reagent tubes, colorimetric paper strips, and a photoionization detector. Corncob, pelleted cellulose, and diced cellulose showed better ammonia control than aspen as early as 4 d after cage changing and throughout the 2-wk measurement period. In addition, pelleted and diced cellulose products resulted in lower ammonia levels than corncob at the end of the 14-d cage-change interval. Our data indicate that pelleted or refined diced cellulose are viable alternatives to natural bedding products in IVC to limit the risk of exposure of mice to high ammonia levels.
氨的控制是啮齿类动物垫料的一个重要特性。在天然垫料中，玉米芯垫料具有优异的氨控制能力，但含有雌激素化合物，并被老鼠摄入。相比之下，经过处理的纤维素垫料产品具有生物惰性，细菌滋生较少，但历史上显示出低吸收性或较差的氨控制能力。为了解决这些缺点，已经开发出了新的纤维素产品。在为期 2 周的时间里，我们使用 4 种垫料类型（去皮白杨、玉米芯、原始颗粒状纤维素和精制原始切丁纤维素）评估了 IVC 笼内的笼内氨水平：通过使用 3 种方法进行测量：有色试剂管、比色纸条和光离子化检测器。早在更换笼后 4 天，玉米芯、颗粒状纤维素和切丁纤维素就显示出比白杨更好的氨控制能力，并且在 2 周的测量期间一直如此。此外，在 14 天的笼更换间隔结束时，颗粒状和切丁纤维素产品产生的氨水平低于玉米芯。我们的数据表明，颗粒状或精制切丁纤维素是 IVC 中天然垫料产品的可行替代品，可降低老鼠暴露于高氨水平的风险。
