Toxicity of anticoagulant rodenticides against Rattus rattus

The potency of four anticoagulant rodenticides viz., brodifacoum, flocoumafen and difenacoum along with bromadiolone at 0.005% cone were evaluated against Rattus rattus under no-choice and choice feeding trial. In both choice and no-choice feeding trials the efficacy of brodifacoum wax block was significantly better than flocoumafen and difenacoum but at par with bromadiolone. In no-choice feeding trial, 100 per cent mortality was achieved with brodifacoum and bromadiolone within 4–9 days observation period but significantly lower mortality was recorded in flocoumafen (80%) and difenacoum (60%). The wax block formulation of difenacoum showed poor palatability as more consumption of plain bait was recorded over poison bait against test animals. Under nochoice test, the poison ingested between male and female was not significant in case of all the toxicants but between brodifacoum and flocoumafen, the difference was significant under choice test. The post treatment consumption of bait was significantly lower in case of brodifacoum and bromadiolone in comparison to flocoumafen and difenacoum. This showed the effectiveness of these two rodenticides (brodifacoum & bromadiolone) against rodent species.