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Table 2 Assessment of ivermectin resistance at the dairy goat farms in the Czech Republic using the larval development test

From: Resistance of strongylid nematodes to anthelmintic drugs and driving factors at Czech goat farms

Farm LD50 ± SD LD99 ± SD Larval development ± SD (%) a Resistance status Recovered nematode species b
(ng.ml-1) (ng.ml-1)
1 0.22 ± 0.03 1.62 ± 0.28 0.0 ± 0.0 S
2 0.34 ± 0.08 5.80 ± 0.64 0.0 ± 0.0 S
3 33.20 ± 6.22 98.41 ± 6.01 4.5 ± 0.4 R Tel/Tri
4 2.21 ± 0.21 12.54 ± 2.69 0.0 ± 0.0 S
5 41.80 ± 1.34 101.39 ± 11.46 17.0 ± 2.7 R Tel/Tri, Hae
6 180.10 ± 35.14 226.00 ± 6.77 79.3 ± 5.1 R Hae, Tel/Tri, Oe/Cha
7 10.02 ± 1.28 76.31 ± 4.43 11.8 ± 1.9 R Tel/Tri, Hae, Oe/Cha
8 11.24 ± 0.66 52.18 ± 4.74 17.0 ± 2.8 R Tel/Tri, Hae, Oe/Cha
9 184.20 ± 22.45 266.44 ± 74.24 80.7 ± 6.3 R Tel/Tri, Hae
10 132.20 ± 14.42 604.80 ± 164.47 57.5 ± 2.2 R Tel/Tri, Hae
11 81.90 ± 34.72 436.59 ± 24.25 68.4 ± 1.7 R Tel/Tri, Hae, Oe/Cha
12 156.30 ± 7.21 258.00 ± 18.13 34.1 ± 3.6 R Tel/Tri, Hae
13 153.50 ± 21.85 549.92 ± 8.03 44.8 ± 5.9 R Tel/Tri, Hae
14 178.10 ± 14.78 228.20 ± 4.91 40.0 ± 4.3 R Hae
15 0.30 ± 0.12 2.19 ± 0.23 0.0 ± 0.0 S
16 0.18 ± 0.03 0.31 ± 0.06 0.0 ± 0.0 S
17 107.10 ± 9.97 352.80 ± 64.59 72.4 ± 6.8 R Tel/Tri, Hae, Oe/Cha
18 4.27 ± 0.01 16.77 ± 2.72 0.0 ± 0.0 S
19 3.77 ± 0.06 40.23 ± 1.20 0.0 ± 0.0 S
20 2.19 ± 0.23 5.70 ± 0.20 0.0 ± 0.0 S
21 20.10 ± 3.18 249.90 ± 13.19 3.5 ± 1.4 R Tel/Tri
22 2.16 ± 0.20 7.60 ± 0.45 0.0 ± 0.0 S
23 2.12 ± 0.19 11.60 ± 1.01 0.0 ± 0.0 S
24 2.74 ± 0.30 5.28 ± 0.65 0.0 ± 0.0 S
  1. Lethal doses (LD50 and LD99) of the ivermectin aglycone expressed as the mean of two measurements ± the standard deviation (SD), a total percentage of infective larvae detected at an ivermectin aglycone concentration of 21.6 ng.ml-1, S herd susceptible to ivermectin, R herd resistant to ivermectin (LD50 > 21.6 ng.ml- 1 and > 30% of larvae developed to L3 stage at 21.6 ng.ml- 1), b species richness of infective larvae recovered at an ivermectin aglycone concentration of 21.6 ng.ml-1; Tel/Tri Teladorsagia/Trichostrongylus, Hae Haemonchus, Oe/Cha Oesophagostomum/Chabertia, the larvae are sorted by their percent occurrence in the sample