Open AccessMoxidectin: A Viable Alternative for the Control of Ivermectin-Resistant Gastrointestinal Nematodes in Beef Cattle
Author(s) -
Dyego Gonçalves Lino Borges,
Mário Henrique Conde,
Cibele Cristina Tavares da Cunha,
Mariana Green de Freitas,
Elio Moro,
Fernando de Almeida Borges
Publication year - 2022
Publication title -
acta veterinaria
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.308
H-Index - 17
eISSN - 1820-7448
pISSN - 0567-8315
DOI - 10.2478/acve-2022-0002
Subject(s) - moxidectin , ivermectin , anthelmintic , abamectin , beef cattle , veterinary medicine , biology , doramectin , feces , placebo , weight gain , zoology , medicine , body weight , agronomy , pesticide , paleontology , alternative medicine , pathology , endocrinology
The increasing prevalence of anthelmintic resistance in cattle especially for avermectins, is a challenge for controlling parasites in some herds. Thus, field studies demonstrating the increase in productivity by the use of anthelmintic formulations, even when a suboptimal treatment (efficacy below 95%), can contribute to the development of gastrointestinal nematodes control programs in beef cattle. The objective of the present study was to evaluate the anthelmintic efficacy and productive performance in pasture-raised beef calves, treated with macrocyclic lactones. A Split plot in time randomized block design was used to assess weight gain and reduction in fecal egg count (FECs) of treatments: 1% moxidectin (1% MOX), ivermectin (IVM) and abamectin (ABM) (2.25% IVM+1.25% ABM), 4% IVM, 3.15% IVM and placebo. For the evaluation of FECs and weight gain of the animals, individual samples were collected seven days before treatment and, +14, +30, +56, +91 and +118 days post-treatment (DPT). The efficacies in the 14th DPT were: 72.3% (1% MOX), 22.1% (4% IVM), 22% (2.25% IVM + 1.25% ABM) and 0% (3.15% ivermectin). 1% MOX was the only treatment that resulted in a significant increase in weight gain of the animals compared to the placebo group after 118 days of treatment, with a difference of 7.6 kg. Therefore, MOX remains a viable alternative for the control of helminths resistant to avermectins and still capable of resulting in significant productive gains, even with an efficacy below 95%.