Flávia Aparecida Nogueira

Effects of Anacardium humile leaf extracts on the development of gastrointestinal nematode larvae of sheep

The rapid development of nematode resistance to anthelmintics has limited the success of small ruminant gastrointestinal helminthiasis control in several countries, stimulating the search for alternatives. The aim of this work was to evaluate the in vitro anthelmintic activity of Anacardium humile (Anacardiaceae) on gastrointestinal nematodes of sheep. Aqueous and ethanolic extracts of A. humile leaves were evaluated by the larval development inhibition assay at concentrations of: 187.5, 150, 100, 50, and 30 mg ml(-1); and 100, 80, 60, 40, and 20 mg ml(-1), respectively. Phytochemical analysis demonstrated the presence of tannins, flavenoids, and alkaloids in the leaves. The LD(50) was 10.14 mg ml(-1) for the aqueous extract and 23.24 mg ml(-1) for the ethanolic extract, providing evidence for the potential of this plant in the endoparasite control.

Diagnóstico do controle e perfil de sensibilidade de nematódeos de ovinos ao albendazol e ao levamisol no norte de Minas Gerais

The anthelmintic resistance is a major obstacle for the nematode control in ruminants and the presence of multiresistant nematodes could make impracticable the activity in a given area. The objective in this study was to evaluate the anthelmintic efficacy of albendazole and levamisole in sheep herds in northern Minas Gerais. The test was performed on ten farms, where we selected three groups of 12 lambs each. Two of these groups were respectively treated with levamisole (5mg/kg) or albendazole (10mg/kg). The third group did not receive treatment. Feces were collected at 0 and 7 day after treatment for the fecal egg reduction test. The nematode genus was evaluated with the identification of the larvae obtained from culture in the feces pre- and post-treatments. For all evaluated herds the levamisole showed high anthelminthic efficacy, which ranged from 90 to 100%. Only for one herd, the albendazole was effective and for six farms, the efficacy of this drug was less than 80%, considered insufficiently active. After the cultivation of larvae were identified mainly Haemonchus spp. and Trichostrongylus spp. The genus Haemonchus was the most prevalent even after treatment of sheep. It is emphasized the importance of in vivo efficacy tests for choosing anthelmintic drugs, since the susceptibility profile varied among sheep herds evaluated in this study.

Efficacy of aqueous extracts of Genipa americana L. (Rubiaceae) in inhibiting larval development and eclosion of gastrointestinal nematodes of sheep

The anthelminthic efficacy in vitro of the aqueous extract of Genipa americana L. leaves was evaluated at final concentrations of 20, 30, 50, 75 and 100 mg (dry matter)/mL through egg hatching inhibition (EHI) tests and quantitative cultures. The observed lethal concentration LC90 values for hatching and L3 development inhibition were 79.8 and 28.7 mg/mL, respectively. The extract was more effective in larval development inhibition (LDI) than in hatching inhibition. Phytochemical analysis revealed tannins and flavonoids in the extract. The utilisation of G. americana as an anthelminthic may represent a viable alternative to synthetic products, although further studies are needed to verify its in vivo efficacy and to assess its toxicity in sheep.

Variação sazonal da contaminação por helmintos em matrizes ovinas e borregos submetidos a controle integrado e criados em pastagens tropicais

The verminosis is one of the principal sanitary problems in ovine herds in Brazil and around the world. However, little is known about the seasonal variation of the helminth contamination and the effects of the combination of a strategy control and a tactical control in sheep raised under in the Northern Minas semiarid conditions. In this study, the objective was to evaluate the seasonal helminth contaminations in lambs and ewes under an integrated control in the North of Minas Gerais, Brazil. The research was carried through during December 2006 to November 2007. Monthly faecal samples from 30 lambs and 30 ewes of one farm were collected. During April 2007, 68 sheep of a second farm were also evaluated, corresponding to the peri-partum time to both farms. The samples were collected directly from the recto and the faecal egg count (FEC) was determined and evaluated by variance analysis. The ewe FEC increased significantly in May and October ,which were peri-partum periods. Lamb FEC increased significantly in March , which coincided with the rainy season end. The integrated control was efficient to reduce the contaminations after these related periods. After the larvae culture, the genus Trichostrongylus, Haemonchus and Strongyloides were the most observed to both dry and rainy periods. During April 2007 the ewe contamination was significantly higher in the second farm that did not treat these animals in the pre-partum.The verminosis is one of the principal sanitary problems in ovine herds in Brazil and around the world. However, little is known about the seasonal variation of the helminth contamination and the effects of the combination of a strategy control and a tactical control in sheep raised under in the Northern Minas semiarid conditions. In this study, the objective was to evaluate the seasonal helminth contaminations in lambs and ewes under an integrated control in the North of Minas Gerais, Brazil. The research was carried through during December 2006 to November 2007. Monthly faecal samples from 30 lambs and 30 ewes of one farm were collected. During April 2007, 68 sheep of a second farm were also evaluated, corresponding to the peri-partum time to both farms. The samples were collected directly from the recto and the faecal egg count (FEC) was determined and evaluated by variance analysis. The ewe FEC increased significantly in May and October ,which were peri-partum periods. Lamb FEC increased significantly in March , which coincided with the rainy season end. The integrated control was efficient to reduce the contaminations after these related periods. After the larvae culture, the genus Trichostrongylus, Haemonchus and Strongyloides were the most observed to both dry and rainy periods. During April 2007 the ewe contamination was significantly higher in the second farm that did not treat these animals in the pre-partum.

Ocorrência e tratamento de miíases cutâneas em ovinos criados em condições semiáridas no norte de Minas Gerais

Cutaneous myiasis was investigated in 10 sheep herds during one year in northern Minas Gerais, Brazil, and factors related to its occurrence were analyzed. The sheep were predominantly hybrid Saint Ines, bred in semi-extensive systems. A total of 50 cases were registered and the highest incidence occurred during March (22%) and April (18%), months with high temperatures and high relative humidity of the air. There was no influence of sex and age for the occurrence of myiasis. The lesions were mostly found on the legs (34% of the cases). Pododermatitis (38% of the cases), omphalophlebitis (10%), lymphadenitis (6%) and dermatobiosis (6%) were the predisposing factors more frequently associated with myiasis. The myiasis was not correctly treated by the owners, but after implantation of a correct therapy, 92% of the lesions presented cure within 7 to 30 days. The results show the importance of preventive strategies based on the predisposing factors identified in this study. The constant inspection, identifying wounds and precociously treating the lesions, should be routine especially at the end of rainy season and when predisposing factors are present.