Efficacy of brodifacoum, A second-generation anticoagulant, against house rat, Rattus rattus (Linnaeus)

Brodifacoum is the most potent second-generation anticoagulant that inhibits the expression of the gene responsible for the synthesis of vitamin K epoxide reductase with approximately 100-fold higher affinity. The study revealed 100% mortality of rats within 3-6 days in no-choice tests and 33.3-66.7% mortality within 3-9 days in bi-choice tests. The lethal feeding period LFP₅₀ determined was 1.81 and 1.82 days in male and female rats, respectively. No significant effect of treatment was observed on body weight and weight of liver, kidneys and spleen. Plain bait consumption was reduced significantly after treatment under no-choice tests. A significant increase in PT (prothrombin time) and APTT (activated partial thromboplastin time) was observed after 24 h of treatment in no-choice tests. The post-treatment INR (international normalized ratio) was 6.2-13.6 in nochoice tests and 2.0-6.2 in bi-choice tests. After two treatments in poultry farms, significantly higher rodent control success was achieved with brodifacoum and bromadiolone baits compared to zinc phosphide bait. The study suggest use of ready-to-use brodifacoum bait in controlling populations of R. rattus as an alternative to other anticoagulant rodenticides.