Control of Rattus rattus with cholecalciferol: laboratory acceptance of freshly prepared and ready-to-use bait formulations

Abstract

The efficacy of cholecalciferol (vitamin D 3) was determined for the control of Rattus rattus in laboratory trials. Two ready-to-use bait formulations (Quintox ® cake and pellets) and freshly prepared poison bait of 0·075% cholecalciferol, using locally available grains, were offered in different combinations in choice and no-choice tests to assess the relative acceptance. Freshly prepared poison bait was preferred to cake or pellet formulations. In no-choice tests, fresh poison bait gave 100% mortality, whereas in choice tests, 70–100% mortality was achieved by offering different combinations of untreated bait, fresh poison bait, Quintox cake and pellets, The rats consumed toxic levels of cholecalciferol in 1–2 days and then showed a sharp decline in feeding, even offered untreated bait. The majority of the rats died within one week after poison bait consumption. High mortality of R. rattus in all the trials suggested field trials of cholecalciferol for the control of commensal rodents.