Degradação de fezes de ovinos após tratamento com ivermectina

Abstract

Gastrointestinal parasites are the greatest health problem for small ruminants farming. High doses of antiparasitic drugs applied to these animals are eliminated mainly through feces and urine, and may impact non-target organisms on environment. The present study aimed to evaluate the degradation time of sheep feces after treatment with ivermectin (IVM). Thus, 10 sheep received 0.63 mg IVM/kg. On the same date of treatment, another 10 animals were kept as untreated controls. Seven and 14 days after treatment, each group of 10 animals was locked in a slatted floor pen, below which a screen was fixed to collect feces. The feces pool of treated and control animals was subdivided into four samples of approximately 200 g. Each sample was deposited in a Panicum maximum plot, that was marked with a toothpick and a colored tape, 1 m apart from each other. A 2x2 factorial design was established in which the effect of the treatment (ivermectin x control) and time after treatment (day 7 and 14) were evaluated, with 4 replicates. The fecal samples were visually monitored by photographic records. The fecal degradation score was evaluated, as well as other indicators of the presence of insects (holes, beetles, anthills). The evaluations were carried out 35, 49, 63 and 80 days after the treatment of the animals. In the feces material deposited after seven days of treatment, little or no material was observed, similar to what occurred with the control group. Likewise, there was little difference in the indicators of the presence of insects near the sample. In the feces deposited after 14 days of treatment, in the feces treated with ivermectin, there was a greater amount of fecal material in the environment in relation to the control group that had little or no material. Thus, there was a difference in the degradation time of feces from sheep after treatment with ivermectin compared to feces from control animals, even when the samples were collected 14 days after administration of the drug.