Efficacy and productive performance of moxidectin in feedlot calves infected with nematodes resistant to ivermectin

Authors
Fazzio, Luis Emilio; Streitenberger, Nicolás; Galvan, Walter Ruben; Sánchez, R. O.; Gimeno, Eduardo Juan; Sanabria, Rodrigo Eduardo Fabrizio
Publication Year
2016
Language
English
Format
article
Status
Published version
Description
Anthelmintic resistance (AR) of gastrointestinal nematodes to macrocyclic lactones is an increasingly common worldwide phenomenon limiting cattle production. This has motivated the search for alternatives, such as new active compounds, added drug synergisms, different doses, and alternate administration routes. The aim of this study was the assessment of moxidectin (MXD) performance in feedlot calves with a history of AR to ivermectin (IVM). Crossbred female calves aged 6-7 months and weighing 163 kg (SD = 34 kg) were divided into 3 groups of 35 animals each. They were assigned to the following antiparasitic treatment groups: IVM group (0.2 mg/kg IVM); MXD group (0.2 mg/kg MXD), and ricobendazole + levamisole (RBZ + LEV) group (7.5 mg/kg RBZ + 8 mg/kg LEV). On days 0, 26, and 47, fecal samples were taken and the weight of each animal was registered. Anthelmintic efficacy (by fecal egg count reduction), total weight gain (TWG) and average daily weight gain (AWG) were compared between the groups. A mixed SAS procedure was used for statistical analysis. Fecal egg count reduction 26 days post-treatment (PT) was calculated at 28% for the IVM group, 85% for the MXD group, and 99% for the RBZ + LEV group. AWGs (Standard Error) of 1.095 g (56), 1.264 g (49), and 1.340 g (52) were registered for the IVM, MXD, and RBZ + LEV groups, respectively (p < 0.05). Coprocultures revealed that MXD more effectively reduced Haemonchus spp. and Cooperia spp. egg counts than IVM. This resulted in higher AWGs and TWGs for this group; similar results were seen for the RBZ + LEV group as well. In this study, animals treated with MXD gained about 160 more g/day than animals treated with IVM. This represents a gain of 16 USD per animal over the 47 day trial.
Fil: Fazzio, Luis Emilio. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; Argentina
Fil: Streitenberger, Nicolás. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; Argentina
Fil: Galvan, Walter Ruben. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; Argentina
Fil: Sánchez, R. O.. Laboratorio Mesopotámico de Diagnóstico Veterinario; Argentina
Fil: Gimeno, Eduardo Juan. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; Argentina
Fil: Sanabria, Rodrigo Eduardo Fabrizio. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; Argentina
Subject
AVERAGE WEIGHT GAIN
CATTLE
COOPERIA
HAEMONCHUS
MACROCYCLIC LACTONES
Otras Ciencias Veterinarias
Ciencias Veterinarias
CIENCIAS AGRÍCOLAS
Access level
Restricted access
License
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
Repository
CONICET Digital (CONICET)
Institution
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identifier
oai:ri.conicet.gov.ar:11336/54562