Economic losses caused by the use of low-efficacy anthelmintic drugs in growing heifers
The aim of this study was to compare the economic revenue related to the use of low- or high-efficacy anthelmintic drugs within suppressive or strategic schemes of treatment in growing heifers. Heifers raised in a semi-intensive grazing system in southern Brazil were used. Levamisole and ivermectin were selected as the high- and the low-efficacy drugs, respectively, based on a previous efficacy test. Subsequently, these drugs were used within strategic (Strat; four times per year) or suppressive (Supp; once a month) treatment regimens in the heifers, and their liveweight and eggs per gram of feces counts were monthly evaluated during a 13-month period. The total costs of the treatments and their cost-benefit ratio in regard to liveweight gain were calculated. Final mean liveweight gains (kg) observed were 126.7 (Strat-Low), 133.6 (Supp-Low), 141.3 (Strat-High), 142.9 (Supp-High), and 125.8 (Control). Treatments with a high-efficacy drug resulted in monetary gains of US$ 19.56 (Strat-High) and US$ 14.98 (Supp-High), but Supp-Low and Strat-Low treatments caused economic losses. Total cost of the efficacy test (US$ 374.79) could be paid by the additional liveweight gain of 20 heifers from the Strat-High group. These results showed that it would be preferable not to treat the heifers against GIN if compared with treating them with a low-efficacy drug. In addition, we showed that the use of four treatments per year with a high-efficacy drug—selected by efficacy test—resulted in a profitable management to control GIN in growing heifers raised in a semi-intensive gazing system in southern Brazil.
KeywordsCattle Economic Nematodes Parasite resistance Weight gain
The authors are grateful for the support of equipment necessary for the accomplishment of parasitological techniques of Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES).
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
- Coles, G.C., Bauer, C., Borgsteede, F.H.M., Geerts, S., Klei, T.R., Taylor, M.A., Waller, P.J., 1992. World Association for the Advancement of Veterinary Parasitology (W.A.A.V.P.) methods for the detection of anthelmintic resistance in nematodes of veterinary importance, Veterinary Parasitology, 44, 35--44CrossRefGoogle Scholar
- Cristel, S., Fiel, C., Anziani, O., Descarga, C., Cetrá, B., Romero, J., Fernández, S., Entrocasso, C., Lloberasi, M., Medus, D., Steffan, P., 2017. Anthelmintic resistance in grazing beef cattle in central and northeastern areas of Argentina—an update, Veterinary Parasitology: Regional Studies and Reports, 9, 25--28Google Scholar
- Edmonds, M.D., Vatta, A.F., Marchiondo, A.A., Vanimisetti, H.B., Edmonds, J.D., 2018. Concurrent treatment with a macrocyclic lactone and benzimidazole provides season long performance advantages in grazing cattle harboring macrocyclic lactone resistant nematodes, Veterinary Parasitology, 252, 157--162CrossRefGoogle Scholar
- Geurden, T., Chartier, C., Fanke, J., di Regalbono, A.F., Traversa, D., von Samson-Himmelstjerna, G., Demeler, J., Vanimisetti, H.B., Bartram, D.J., Denwood, M.J., 2015. Anthelmintic resistance to ivermectin and moxidectin in gastrointestinal nematodes of cattle in Europe, International Journal for Parasitology: Drugs and Drug Resistance, 5, 163--171PubMedGoogle Scholar
- Heckler, R.P., Borges, D.G.L., Vieira, M.C., Conde, M.H., Green, M., Amorim, M.L., Echeverria, J.T., Oliveira, T.L., Moro, E., Van-Onselen, V.J., Borges, F.A., 2016. New approach for the strategic control of gastrointestinal nematodes in grazed beef cattle during the growing phase in central Brazil, Veterinary Parasitology, 221, 123--129CrossRefGoogle Scholar
- Lopes, W.D.Z., dos Santos, T.R., Sakamoto, C.A.M., de Lima, R.C.A., Valarelli, R.L., Paiva, P., da Costa, A.J., 2013. Persistent efficacy of 3.5% doramectin compared to 3.15% ivermectin against gastrointestinal nematodes in experimentally-infected cattle in Brazil, Research in Veterinary Science, 94, 290--294CrossRefGoogle Scholar
- Martínez-Valladares, M., Geurden, T., Bartram, D.J., Martínez-Pérez, J.M., Robles-Pérez, D., Bohórquez, A., Florez, E., Meana, A., Rojo-Vázquez, F.A., 2015. Resistance of gastrointestinal nematodes to the most commonly used anthelmintics in sheep, cattle and horses in Spain, Veterinary Parasitology, 211, 228--233CrossRefGoogle Scholar
- Morel, N., Signorini, M.L., Mangold, A.J., Guglielmone, A.A., Nava, S., 2017. Strategic control of Rhipicephalus (Boophilus) microplus infestation on beef cattle grazed in Panicum maximum grasses in a subtropical semi-arid region of Argentina, Preventive Veterinary Medicine, 144, 179--183CrossRefGoogle Scholar
- Ramos, F., Portella, L.P., Rodrigues, F.S., Reginato, C.Z., Pötter, L., Cezar, A.S., Sangioni, L.A., Vogel, F.S.F., 2016. Anthelmintic resistance in gastrointestinal nematodes of beef cattle in the state of Rio Grande do Sul, Brazil, International Journal for Parasitology: Drugs and Drug Resistance, 6, 93--101PubMedGoogle Scholar
- SAS Institute, 2011. Statistical analysis system user’s guide: statistics, version 9.3. Cary, USAGoogle Scholar