[Experimental deratization on a commercial swine-breeding farm]

Continuous eighth-month deratization was carried out on an industrial swine breeding complex, having great numbers of the black rat (R. rattus). Anticoagulants were chiefly used, maintaining permanent sites of poisonous baits. The lowering of rat numbers was followed up at two-month intervals in the individual productional sectors. Some indices were determined, such as intensiveness, extensiveness, and effectiveness. It was found that each of these indices characterized particular aspects of the deratization process on the complex as a whole and in the various sectors. A suggestion is made to use all indices in combination in assessing the effect of deratization on such complexes, particularly when due attention is to be paid to the epizootic importance of deratization. With regard to the economic effect it has been established that even with uninterrupted process of deratization for a long period of time on the entire area of a swine breeding complex this measure is economically expedient. Great amounts of valuable feed are economized owing to the lower number of rodents.