1. Economic losses caused by the use of low-efficacy anthelmintic drugs in growing heifers
- Author
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Marta Lizandra do Rêgo Leal, Camila Balconi Marques, Marta Elena Machado Alves, Felipe Lamberti Pivoto, Camila Coelho Becker, Fernanda Silveira Flores Vogel, and Alfredo Skrebsky Cezar
- Subjects
Male ,040301 veterinary sciences ,Cattle Diseases ,0403 veterinary science ,Feces ,Animal science ,Ivermectin ,Food Animals ,Grazing ,Animals ,Medicine ,Anthelmintic ,Nematode Infections ,Parasite Egg Count ,Eggs per gram ,Ovum ,Anthelmintics ,business.industry ,Treatment regimen ,0402 animal and dairy science ,04 agricultural and veterinary sciences ,Levamisole ,040201 dairy & animal science ,Cattle ,Female ,Animal Science and Zoology ,medicine.symptom ,business ,Weight gain ,Brazil ,medicine.drug - Abstract
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.
- Published
- 2019