Effects of 3 Rodent Beddings on Biochemical Measures in Rats and Mice.

Components of bedding might interact with experimental treatments and affect the outcome of various experiments. Here we studied the biochemical effects of 3 rodent bedding materials that are commonly used in Egypt. Male and female rats and mice were assigned randomly into 4 single-sex and single-species groups (10 animals per group). Three types of bedding-rice straw, wheat straw, and pine wood shavings-were evaluated. After 4 wk, animals were euthanized, and biochemical parameters were measured. In male and female rats given wood shavings, serum ALT activity and malondialdehyde concentration increased whereas catalase activity decreased compared with levels in the wheat straw group. In contrast, ALT activity and malondialdehyde concentrations decreased but CAT activity increased in rats housed on rice straw compared with wheat straw. Serum AST and ALT activities increased in male and female mice exposed to rice straw, whereas the malondialdehyde concentration increased and catalase decreased in the wood shavings group relative to the wheat straw group. In mice exposed to wheat straw, AST and ALT activities and malondialdehyde concentrations decreased and CAT activity increased compared with the other groups. Because our results showed that exposure to wood shavings affects some biochemical parameters of rats and mice, we do not recommend its use as laboratory animal bedding. We consider that, of the materials tested, rice straw bedding is the best bedding material for rats, whereas wheat straw is best for mice.