RESUMEN
@#This research was undertaken to evaluate the nematicidal activity of various concentrations of aqueous tinctures of 80 plant species towards L1–2 of S. papillosus. For the experiment with larvae of S. papillosus, there were used 0.19%, 0.75% and 3.00% aqueous tinctures of plants. Out of 80 tested species, nematicidal activity against L1–2 of S. papillosus was displayed by 20 plants. The greatest activity (LC50 = 0.060–0.069%) towards larvae of S. papillosus was exerted by Teucrium polium, Achillea millefolium, Genista tinctoria and Ulmus laevis. Less expressed nematicidal activity (LC50 = 0.070–0.079%) was recorded for Thalictrum minus, Stachys recta, Falcaria vulgaris, Lavatera thuringiaca. Even lower effect (LC50 = 0.080–0.089%) was shown by aqueous tinctures of Mentha × piperita, Achillea millefolium, Salvia nutans, Eryngium campestre and Cerasus fruticosa. The following plants could be arranged in declining order of effectiveness of nematicidal activity (LC50 = 0.090–0.165%) Malus sylvestris, Tragopogon orientalis, Erigeron annuus, Grindelia squarrosa, Urtica dioica, Daucus carota, Medicago sativa, Carduus acanthoides, Ulmus minor and Hieracium umbellatum. A far weaker effect on the nematodes was displayed by Bromopsis inermis and Tragopogon podolicus. Aqueous tinctures of 60 other studied species of plants exhibited low nematicidal activity in 3.00% aqueous tincture, while in 0.19% and 0.75% aqueous tinctures, no nematicidal activity was seen. The results of the research suggest that in the conditions of natural ecosystems, some species of plants of the Apiaceae, Asteraceae, Fabaceae, Lamiaceae, Malvaceae, Rosaceae, Ulmaceae and Urticaceae families could reduce vitality of free-living L1–2 larvae of S. papillosus.
RESUMEN
Durante un ensayo para evaluar la eficacia de dos formulaciones antihelmínticas para bovinos (Moxidectina como Cydectin NF® y Doramectina como Dectomax®), se estudiaron in vivo la carga parasitaria y las especies de estrongilidos presentes en caballos criollos venezolanos con altos contajes de estróngilos. El estudio fue llevado a cabo en la Estación Experimental La Iguana de la Universidad Simón Rodríguez (UNESR), Municipio Santa María de Ipire, estado Guárico (Venezuela), en cuatro caballos adultos con alto contaje de estróngilos (más de 1000 huevos por gramo de heces, hpg) mediante recuperación de parásitos post-tratamiento. Los animales fueron asignados a uno de los siguientes grupos (una hembra y un macho en cada uno); G1M: tratados con 0,4 mg/kg de peso corporal (PC) de Moxidectina, vía subcutánea (sc); G2D: tratados con 0,3 mg/kg de PC de Doramectina vía sc. Se tomaron muestras fecales (500 g aproximadamente) a las 24 y 48 h post-tratamiento para la recuperación in vivo de las especies de nemátodos Strongylidae presentes. En los animales tratados con Moxidectina sólo se obtuvieron nemátodos a las 48 h post-tratamiento. En los animales machos se recuperaron 325 parásitos, mientras que en las hembras se recuperaron 201 parásitos de la familia Strongylidae. En el grupo tratado con Doramectina, se observaron nemátodos a las 24 y 48 h post-tratamiento. En los machos se recuperaron 136 parásitos y en la hembra sólo tres parásitos. Se observaron seis géneros: Cylicocyclus, Coronocyclus, Cyathostomum, Cylicostephanus, Triodontophorus y Poteriostomum, y 16 especies, siendo Cylicocyclus nassatus la especie con mayor abundancia e intensidad. Posteriostomum imparidentatum se reporta por primera vez en caballos criollos venezolanos. La recuperación de parásitos post-tratamiento es una buena alternativa para la estimación de la carga y composición de la comunidad de parásitos estrongilidos cuando las necropsias no son posibles o no son deseables.
During an assay to evaluate the efficacy of two bovine anthelminthic formulations (Moxidectin as Cydectin NF® and Doramectin as Dectomax®), the in vivo parasitic burden and the strongyles species present in four adult Venezuelan Creole horses with a high strongylid count were studied. The study was carried out at Estación Experimental La Iguana de la Universidad Simón Rodríguez (UNESR), Municipio Santa María de Ipire, estado Guárico (Venezuela). A total of four adult horses with a high strongylid count (more than 1000 eggs per gram of feces) through a post treatment parasite recovery were used. Horses were allocated into 2 groups (one male and one female per group), as follows: Group I: two animals treated with a subcutaneous (sc) injection of 0.4 mg/kg body weight (BW) of Moxidectin; Group II: two animals treated with a sc injection of 0.3 mg/kg BW of Doramectin. Samples of feces (approximately 500 g) were collected at 24 and 48 h post-treatment for the in vivo recovery of the strongyles species present. The results showed that nematodes were only seen in animals from Group I 48 h post-treatment: 325 individual parasites of the Strongylidae family were recovered in males and only 201 in females. In Group II, nematodes were observed at 24 and 48 h post treatment, with 136 parasites recovered in males and only 3 in females. Six genuses were observed: Cylicocyclus, Coronocyclus, Cyathostomum, Cylicostephanus, Triodontophorus y Poteriostomum and sixteen species, being Cylicocyclus nassatus the species with more abundance and intensity. Posteriostomum imparidentatum is reported for the first time in Venezuelan Creole horses. The post-treatment parasite recovery is a good alternative for the estimation of the parasite burden and the composition of the strongylid parasite community when necropsy studies are not available or desirable.