Consequences of Premature Weaning on the Reproduction of Mothers and Offspring in Laboratory Mice

A decrease of energy expenditure per offspring is expected to benefit the mother by increasing the number of offspring she can produce, and to inflict costs upon the young by decreasing their reproductive value. To evaluate the benefit-cost functions of shortened suckling times in house mice, the young were separated from their mothers prior to natural weaning. During two following litters of mothers and young, time of birth and numbers born were recorded. The impact of the resulting effects on the lifetime reproduction of mothers and young were evaluated by model calculations assuming population equilibrium, exponential population growth or exponential growth limited by population breakdowns.