Dr. Murai Éva szerk.: Parasitologia Hungarica 23. (Budapest, 1990)

Table 5 Toxicity test (without choice) in rats and mice Duration of rodenticide feeding Mortality Rodenticide consumption (g) Day of death Duration of rodenticide feeding n % mean extreme values mean extreme values RAT Till death 10/10 100 110 4 82 2 129. 6 6. 5 6-8 4 days 10/10 100 72 1 63 1 87 5 6. 8 5-9 3 days 10/10 100 52 0 35 4 69 4 6. 7 5-9 2 days 10/10 100 40 7 24 4 60 2 5 . 9 4 -10 1 day 10/10 100 17 0 9 o 25 0 6. 9 4-9 MOUSE Till death 10/10 100 18 9 9 6 25 0 6. 0 6 4 days 10/10 100 16 3 7 5 25 2 4 . 9 3-6 3 days 10/10 100 11 6 8 6 16 6 5 . 0 4-6 2 days 10/10 100 8 2 6 0 10 6 5 . 0 4-6 1 day 10/10 100 5 1 2 0 6 9 5 . 4 5-6 3. The aim of the third series of experiments was to determine to what extent sugar improved the acceptance of the poisoned bait. Namely, from palatability trials conducted earlier in Hungary and by HERMANN (1974) and HOWARD (1972, 1977) rats are known to like the sweet taste. In the free choice experiment we added different amounts (2.5, 5, 7.5 or 10 %) of sugar to the LANIRAT-B bait containing hulled oat as vehicle. Our aim was to determine the optimal sugar concentration. A sugar concentration of 5 % proved to be optimal (Fig. 2), as in the free choice experiments baits of this sugar concentration showed the highest level of acceptance (81.2 and 70.3 % for rats and mice, respectively). These are outstandingly good values and indicate extraordinarily high palatability. The mortality rate was consistently 100 % in these experiments, too, and the average time of mortality was 6.1-6.7 days (Table 2). 4. The LANIRAT-B formula of 5 % sugar concentration, which proved to be optimal in the appetibility tests, was compared to an outdated bait, TOMORIN-B (Table 3 and Fig. 4). The acceptance of these two baits was tested against EPA as standard. Table 3 shows that the laboratory rats preferred LANIRAT-B 4.3 times more to the EPA standard; however, they preferred the EPA standard 4.4 times more to the TOMORIN-B bait. These comparative palatability tests showed that the rats preferred LANIRAT-B nearly three times more to the TOMORIN-B bait (Table 3).