Bedding material is the material closely contacted with the feeding and using process of experimental animals, which is used to absorb the excreta of animals, reduce the concentration of ammonia in the cage, and keep the cage dry. It is an important environmental factor related to the health and welfare of experimental animals, affecting the physiological activities of experimental animals and the accuracy of experimental results.

At present, the commonly used cushion materials are wood cushion (shavings, sawdust), corncob, straw, recycled paper, new cushion materials, etc. Among them, because of its rich resources and low price, wood cushion has become the most commonly used contact cushion. There are two kinds of commercial wood cushion products: wood chips and shavings. In contrast, shaving pad has the advantages of soft texture, good comfort and water absorption, suitable for nesting, and not easy to adhere to animal fur to affect the appearance. In order to meet the needs of transportation and storage space, commercial compressed shaving bedding materials have been developed.

When making wood bedding, it is necessary to avoid using pine and cedar materials with aromatic smell. This kind of fragrant volatile compounds can induce the activity of liver microparticle enzyme, damage the liver cells, greatly disturb the animal experiments in pharmacology and toxicology, and harm the health of animals at the same time. At present, poplar and birch are the main raw materials used in the production of shaving pad in China. So what's the difference between these two kinds of materials?

Poplar has the advantages of fast growth, strong adaptability, good processing performance and wide use of wood. It is the first choice of fast-growing and high-yield forest and short-term industrial forest in China. It is widely planted in the north and south of China, with rich resources. Birch is a kind of deciduous tree or shrub, which is mainly distributed in Northeast and North China. Its material is white, its texture is straight, its structure is fine, and its hardness is medium. It is one of the excellent tree species suitable for pulping and papermaking. Both poplar and birch can meet the requirements of experimental animal bedding. But what's the difference between the two kinds of shaving padding after compression? We did a small experiment for this.

We split some of the two kinds of compressed shaving pad on white paper and put the upper pad in one place. As can be seen from the figure, more fine particles and powder can be seen under the Compressed Poplar shaving cushion pile. In the actual use process, these fine particles and powder will become the dust in IVC cage or isolator, affect the cage environment of animals, and more easily block the filtering system of equipment. This may be due to the fiber properties of poplar, which produce more powder in the compression process. In addition, comparing the texture of the two, we can feel that birch wood is softer and more animal friendly.

To sum up, we recommend birch as the raw material in the selection of compressed log cushion.