Reproduction and Growth of Mice of three Strains, after Transfer to -3° C

Abstract

Mice of strains A, C57BL and GFF were mated at environmental temperatures of 21 and - 3° C, with a few pairs also at 10° C. All pairs had nesting material. Growth was reduced at -30° C. in all strains. Weights of A and C57, but not GFF, young on weaning at 3 weeks were reduced at -3° C. The number of litters per pair, and of young weaned per pair, was reduced at -3° C. for all strains, but especially C57 and GFF. The fertility of the GFF strain at 21° C. is lower than that of the other strains: consequently, the GFF mice did very badly in the cold. Reproductive performance at 10° C. was similar to that at 21° C. for all strains.