German, A., Unit of Vertebrate Pest Control, ARO, The Volcani Center, Bet Dagan, Israel

Reproduction of 105 females of Levant vole (Microtus guentheri), which ingested diethylstilbestrol (DES) with their mothers' milk at the age of 0-12 days, and of 62 control females, was studied. In most cases ingestion of DES did not cause sterility, but delayed sexual maturity by 1.5-2 months. This delay was observed in all of the females which ingested DES when they were newborn and 1 day old, in 50% of those that received it at the age of 2 days, and in only 30-40% of those that received it at an older age. Ingestion of DES had no effect on litter size or sex ratio. The total pup production of females which were given DES through their mothers' milk was about half that of control females. © 1981 Springer Science + Business Media B.V.