On Effectiveness of Mouse-Like Rodent Control Methods in Livestock Breeding Complexes
Mouse-like rodents cause huge damage to farming industry, increasing the risks of mechanical damage, epidemics and epizootics. In livestock breeding complexes, chemical deratting events are particularly difficult, since it is necessary to take into account the susceptibility of farm animals to poisons used in rodent control. The subject matter of my study is effectiveness of modern chemical and mechanical methods of mouse-like rodent control. Aimed to selecting effective combinations of chemical and mechanical methods of disinfestation for use in the practice of struggle against rodents in livestock farms, I outlined history and practice of pest control, primarily in Russia, and carried out series of experiments on 230 rats Rattus norvegicus Berk. and 240 house mice Mus musculus L. followed by comparative analysis of the effectiveness of chemical and mechanical means of combating rodent control. In my experiments, I used finished forms of rodenticides in the form of grain bait, granule, soft and paraffin pellets, capsules, wafers, tablets, pastes with active substances with a certain concentration. During the experiment, I performed a comparative analysis of poison bait palatability and feed alternative, defined death time for rodents and number of dead animals as a percentage of the total rodents numbers in the experiment. The criteria for evaluating the effectiveness of finished forms were the following indicators: (i) for acute-effect rodenticides: (a) death of mice and rats in the presence of an alternative feed - at least 80%; death time (24-hour period) - no more than 3%; (b) mice and rats’ palatability of ready form of rodenticides or prepared standard poisoned bait in the presence of alternative food - not less than 10% of the daily ration; (ii) for anticoagulants of 1st generation: (a) death of mice and rats in the presence of an alternative feed - 80%; time of death (24-hour period) - not more than 14%; (b) mice and rats’ palatability of the ready form of rodenticides or prepared standard poisoned bait in the presence of alternative food (except bait for mice based on ethilphenacyn, zookumarin (d,l-3 alfa-acetonylbenzyl-4-oxycumarine), coumatetralyl) - not less than 15% of the daily ration; (c) mice’s palatability of the ready forms of rodenticides or prepared standard poisoned bait on the basis on ethilphenacyn, zookumarin, coumatetralyl in the presence of alternative food - not less than 20% of the daily ration; (iii) for anticoagulants of 2nd generation: (a) death of mice and rats in the presence of an alternative feed - not less than 90%; time of death (24-hour period) - not more than 10%; (b) mice and rats’ palatability of the ready form of rodenticides or prepared standard poisoned bait in the presence of alternative food - not less than 15% of the daily ration. For evaluating effectiveness of repellents I carried out followings. Experiment was performed in a cage divided into two halves by a partition with two openings. Rodent of the nest part of the cage strives through this or that hole to get into half, where food and water are. In the experiment, one of the holes was closed with filter paper screen treated by repellent solution, while the other hole was blinded by untreated screen. I assessed repellent efficacy by ‘damage factor’ that was determined by ratio of number of damage done by rodent in repellent-treated screen to the number of those in untreated one. The criterion for evaluating the mechanical device (traps, live-traps) was an efficient operation it is not less than 80% of cases, for adhesive mass it was possibility to hold at least 80% of animals weighing no more than 100 g. I have shown that (i) the most effective for rodents control are means based on anticoagulants (such as bromadiolone, diphenacyne, phloucumaphen, brodifacoum, a-naphthylthiourea), and the mechanical traps (adhesive, spring traps, live-traps, creel-like traps); (ii) adhesive traps are unfit for rat control due to relatively large rat body mass; (iii) household ultrasonic insect repellent does not affect the behavior of mice; it induces deterrent effect in the rat only at a frequency of 22 kHz; (iv) chemical repellant based lavandin oil attracted animals instead of driving them; (v) grains, pellets and soft briquettes were most effective ready forms for chemical both mice and rats control; (vi) mice were more resistant to anticoagulants than rats. The average mortality in mice by advancing anticoagulants was 5-7 days, while for rats it was 3-5 days; (vii) male rats are less resistant to the toxic effects, particularly phloukumaphen, compared with females ones, according to their more early mortality. However, these differences may be due to the fact that male rats are better to eat all the bait offered to them, resulting in an average daily dose of poison is greater. I conclude, to successfully rodent control in livestock enterprises it is better to use complex tools (anticoagulants-based rodenticide in conjunction with the mechanical traps). To improve rodents control efficiency indoors in places inaccessible to farm animals, it is advisable to use such formulations as paraffin pellets and briquettes soft. Etched grain can be placed only where farm animal does not find it invariably, i.e. in storage rooms, pantries, warehouses. In the vicinity of farm animals, it is safer to place mechanical traps: adhesive stickum, traps, live-traps and ‘bait houses’. Contents of ‘bait houses’ may be varied: pastes and gels deposited on the wall, the bait finished forms of different active ingredients.