Resistência anti-helmíntica e controle biológico de nematódeos gastrintestinais de ovinos em ambiente semiárido.

Abstract

In Chapter I, the objective of this study was to evaluate the action of Monepantel and other anthelmintics on gastrointestinal nematodes of sheep of the Paraíba Semi-arid. The second is the influence of the three-year storage time of M. thaumasium pellets on the predation of infective larvae of tricostrongilide sheep. The first study was developed in 20 properties, where we used 30 sheep from each farm without anthelmintic treatment for at least three months. The animals were divided into five groups: group I, treated with 2.0 mL / 10 kg of 10% Albendazole; group II, treated with 2.5 ml / 10 kg Ivermectin 0.08%; Group III treated with 1.0 mL / 10 kg of 10% Closantel; Group IV, treated with 1.0 mL / 10 kg of 5% Levamisole Hydrochloride; and group V treated with 1.0 mL / 10 kg of 2.5% Monepantel. Fecal samples were collected at days zero and ten to perform fecal analyzes. To evaluate the resistance, the reduction test was applied in egg count per gram of feces (RCOF) and coproculture. Multiresistance was observed in all the properties evaluated, where 95% of the farms had high resistance to Albendazole, 85% to Ivermectin, 80% to Closantel, 40% to Levamisole and 45% to Monepantel. The second TRCOF for Monepantel was performed four months after the first one at property 15, where the vermifuge was ineffective, resulting in 75% efficacy. Two sheep were euthanized and necropsied, and Haemonchus contortus, Trichostrongylus axei, Trichostrongylus colubriformis, Oesophagostomum columbianum and Trichuris ovis were recovered. The second study was carried out at the Federal Institute of Paraíba, Sousa campus. Eight negative OPG sheep were divided into four experimental groups: Group I, 3g / 10kg of pellets of M. thaumasium - 36 months of storage, dose only; Group II, 3g / 10 kg of M. thaumasium pellets - freshly produced, single dose; Group III, 3g / 10 kg p.v, of pellets without fungi; Group IV, control. Every 24 hours, up to 120 h, the faeces of the animals were collected and sent to the Veterinary Parasitology Laboratory for analysis. Fifteen grams of feces from each animal were weighed and five grams of expanded vermiculite were added, the coprocultures were added and 1000 infective larvae (L3) of tricostrongilídeos of ovinos, being the larval recovery realized after seven days. It was observed that the predation of larvae in Group I (M. thaumasium - 36 months) did not differ statistically (p> 0.01) from Group II (M. thaumasium - recent), respectively presenting reductions of 75 and 79%. Both groups added peak predation to larvae at 72 h. The genus of helminth most recovered in coprocultures was Haemonchus sp. It was concluded that the gastrointestinal nematodes of sheep are resistant to monepantel and that the occurrence of multi-resistance to anthelmintic by these nematodes was frequent. It was concluded that the 3-year storage period of M. thaumasium in the alginate matrix did not influence the efficacy of predation of sheep trichotrongilide larvae with high reduction of larval recovery and presence of fungal activity in the feces up to 96 hours after administration animals.