Abstract
Recently a Mongolian gerbil has become a useful laboratory animal, while little ofthe basic data are known about the breeding and growth of this laboratory rodent.In our animal center, an inbred strain of the seizure prone gerbil has been producedand kept these ten years. The data on the breeding and growth of the animal wereobtained and described as following in the present paper. 1. The mean life span was26±14month old for males and 27±13 month old for females.2. The mean bodyweight of the Mongolian gerbils at 16 weeks of age was 72±5.6g for males and 62±7.3gfor females.3. The mean litter size at birth was 4.8±1.7 head. (range; 1-9) 4.More newborn pups were born in the warm seasons (March-October) than the coldseasons (November-February) . 5. The mean rate of weaning was 80.2%. 6.Theman litter size was relatively constant in each generation.
