Summary: Positively perturbed generators of locally Lipschitz continuous increasing integrated semigroups on an abstract \(L\) space are again generators of locally Lipschitz continuous increasing integrated semigroups. Positively perturbed generators of positive dual semigroups on a dual abstract \(L\) space are generators of semigroups with various continuity properties in the weak* topology. These results are reformulated in terms of cumulative outputs and then applied to age-structured models for population dynamics.