[Effects of feed and mating age on reproductive performance in Syrian hamsters]

In order to utilize Syrian hamsters in selection experiments, we investigated desirable conditions of feed and mating age for reproduction in females. Hamsters were subdivided into two groups, raised on pellet feed for herbivores (ZC-2) and breeding (MB-1), respectively. Half of the hamsters in each group were switched to the other feed, respectively, after mating. They were mated at 8 or 12 weeks of age. In the group that has been fed on ZC-2 before mating and MB-1 after mating, there was significantly more females giving birth and weaning, and exhibited the largest litter size and litter weight at 3 weeks of age (P < 0.01). The hamsters of the groups mated at 12 weeks of age exhibited a higher percentage of females giving birth and litter size and litter weight at birth than those at 8 weeks of age, but that was no significant difference in litter size and litter weight at 3 weeks of age. We conclude that Syrian hamsters raised by fibrous feed before mating gave optimal reproductive performance.