The impact of anthelmintic resistance on beef cattle productivity

CANTON, C.; CEBALLOS, L.; MORENO LAURA; FIEL, C.; DOMINGUEZ, P.; CANTÓN, L.; BERNAT, G.; LANUSSE, C.; ALVAREZ, L.

Kuala Lumpur

Congreso; 26º Conference of the World Association for the Advancement of Veterinary Parasitology WAAVP. Kuala Lumpur, Malaysia; 2018

The World Association for the Advancement of Veterinary Parasitology WAAVP.

WAAVP 2017 Abstract Book.pdfOral Presentation ? 5 Sept 2017: Drug ResistanceAbstract No: 4531 5 Sept 2017, 1500 - 1515 The impact of anthelmintic resistance on beef cattle productivity Candela Canton*1 ; Laura Ceballos1 ; Laura Moreno1 ; Cesar Fiel2 ; Paula Domínguez1 2 ; Lucila Canton1 ; Giselle Bernat2 ; Carlos Lanusse1 ; Luis Alvarez1 1 Laboratorio de Farmacología/ Centro de Investigación Veterinaria Tandil, UNCPBA-CICPBA-CONICET, Facultad de Ciencias Veterinarias/ Argentina 2 Laboratorio de Parasitología/ Centro de Investigación Veterinaria Tandil, UNCPBA-CICPBA-CONICET, Facultad de Ciencias Veterinarias/ Argentina Abstract Content The goal of the current study was to evaluate, in a commercial beef-cattle farm, the impact of anthelmintic resistance (AR) on the productivity of calves naturally infected with gastrointestinal nematodes resistant to ivermectin (IVM) and moxidectin (MXD).This trial included two herds grazing on different forage resources: Herd A in a maize-winter forage crop rotation (low re-infection) and Herd B in a two-year-old Agropyrum pasture (high re-infection). In each herd, eighty male calves were randomly allocated into four groups (n= 20): Control group (CG): without anthelmintic treatment; IVM group: treated with IVM (0.2 mg/kg); MXD group: treated with MXD (0.2 mg/kg); IVM+RBZ group: treated with IVM and ricobendazole (RBZ) (0.2 and 3.75 mg/kg, respectively). All treatments were given by the subcutaneous route. The clinical efficacy was determined by FECRT 20 days post-treatment. On days 0, 20, 35, 67 and 90, individual weights were registered. The clinical efficacies were 42% (IVM), 67% (MXD) and 99% (IVM+RBZ). Cooperia spp. and Haemonchus spp. were the genera involved in AR. In Herd A the total weight gains (TWGs) in the 90 day-period increased by 0% (IVM), 59% (MXD) and 90% (IVM+RBZ) compared with the Control group. In Herd B the TWGs increased by 64% (IVM), 97% (MXD) and 151% (IVM+RBZ) compared with the Control group. The effect of AR on live weight gains was significant (Tukey, P