Estudo da eficácia de três classes de anti-helmínticos em ovelhas prenhas

Abstract

Parasitosis is one of the issues that strongly impact sheep production, affecting the production system as a whole and sometimes even leading the animal to death. This study aims to evaluate the effectiveness of three anthelmintic classes in pregnant ewes, managed in Natural Pasture. The experiment was conducted in a private property within the municipality of Lavras do Sul / RS, located in the Campanha Gaucha region. Forty half blood Corriedale, originated from crosses with purebred Corriedale sheep were used. On day zero (D0) the collection of feces was carried out directly from the rectum to determine, through laboratory diagnosis, eggs count per gram of feces (ECG) and faces culture technique. Subsequently, the animals were divided in 4 groups of 10 sheep each. Group 1 received the active principle Ivermectin 1% (T1), Group 2 received Closantel (T2), Group 3, Levamisole (T3), and animals from Group 4 did not receive any dosage, called control group. The animals were also evaluated by body weight and your body condition score (BCS). The animals were kept in Natural Pasture with mineralized salt offer and after 14 days were taken more samples of feces for ECG and feces culture technique. It was observed a reduction of ECG (P> 0.05) in groups given Closantel and Levamisole treatments, with efficacy over 95% just for the Closantel Treatment. The species of parasites found were Haemonchus spp, Trichostrongylus spp, Ostertagia spp, Cooperia spp, Bunostomum spp and Oesophagostomum spp, 75%, 21%, 2%, 1% and 1% of variability, respectively. For parasitic resistance results it was observed an anthelmintic inefficiency with Ivermectin at 1%. Treatment with Closantel was 98% effective, and treatment with Levamisole, 89%. When comparing the mean of ECG between treatments in each application, there was significant difference between Ivermectin at 1% and Closantel, but there was no significance between Ivermectin at 1%, Levamisol and Control. There was efficacy in only one active principle used, the others were not efficient in controlling the parasitosis in the studied property.