Eficácia das Lactonas Macrocíclicas em bovinos naturalmente infectados na mesorregião do sertão paraibano.

Abstract

Gastrointestinal helminthes infections in bovines cause big economic losses, due to mortality and reduction of animals’ productivity. The control of these parasites is based mainly on the treatment of the animals with anthelmintics substances. However, this control is not always effective because of the constant appearance of populations of resistant parasites. This work aimed to contribute to the reduction of the problem of verminosis in 72 female bovines of Sindi and Gyr breeds and also the ones with non- specific breed standards. Within each breed, the animals were distributed in three treatments (moxidectine, ivermectine and doramectine), with a dose of 200 mcg/kg pv and a controlled group, in a totally casual treatment. Were collected feces to carry out the OPG, in day zero the vermifugation was carried out. The blood collection to analysis of the hematocrit (PCV) as well as the animals weighing to the days zero, seven, fourteen and twenty-one, post-treatment. To evaluate the resistance, it was used the reduction of eggs counting per gram of feces test and the coproculture. In the study with the animals of non-specific breed standards and the ones of Sindi breed, the following results were observed: to the evaluation, the reduction of eggs counting per gram of feces test and the coproculture were used. The following results to the reduction of eggs counting per gram of feces test were obtained, considering the breeds, the medicine and the days of evaluation: in the treatment of the non-specific breed standards animals, the moxidectine reduced 97% and in the ones of Sindi breed, it reduced 100%; with ivermectine on the ones with non-specific breed standards, it reduced between 100% and 2% and on Sindi breed between 50,28% and 91,79% and with doramectine on the ones with non-specific breed standards, between 92% and 70% and on Sindi breed between 86,8% and 91,79%. In coproculture, the genre Haemonchus, followed by Trichostrongylus, Cooperia, Oesophagostomun and Strogyloides were less identified after the treatments. There was no significant difference (p > 0.05) in the average weigh gain and hematological exam of the treated groups in relation to the controlled group. In the study with the animals of non-specific breed standards and Gyr breed, the following results were obtained: to the evaluation, it was used the reduction of eggs counting per gram of feces test and the coproculture. The following results were observed to the reduction of eggs counting per gram of feces test, considering the breed, the medicine and the days of evaluation: in the treatment of nonspecific breed standards animals the moxidectine reduced 97% and in the Sindi breed it reduced 100%; with ivermectine in non-specific breed standards animals between 99% and 2% and in Sindi breed between 50,28% and 91,79% and with doramectine in nonspecific standards breed animals between 92% and 70% and in Sindi breed between 86,8% and 91,79%. In coproculture, the genre Haemonchus, followed by Trichostrongylus, Cooperia, Oesophagostomun and Strogyloides, were less identified after the treatments. There was a significant difference (p > 0.05) in the average weigh gain of the treated and controlled groups. The hematological values did not show any significant changes, this happened, possibly, due to the fact that this parasite stays in the small intestines, and did not cause a huge harm on the animals.