Effect of eucalyptus oil no controle do carrapato bovino

This research was aimed at evaluating in vitro and in vivo effects of eucalyptus (Corymbia citriodora) oil on cattle ticks (Rhipicephalus (Boophilus) microplus). Negative control group and eight concentrations of eucalyptus oil (0.5; 1; 2; 5; 10; 20; 50; 100%), were used on in vitro trials with engorged female ticks. The efficacy of control ticks was 0; 30.5; 75.5; 91; 100; 100; 100; 100 and 100%, respectively. At the in vivo trial eighteen Holstein cows were allocated to three groups (negative control, eucalyptus oil at 3.5%--level estimated by regression analysis, accounting for 95% efficacy of control ticks on in vitro trial and amitraz at 0.025%). Engorged female ticks were counted before (mean of days -3, -2, -1) and after treatment (1, 2, 3, 5, 7, 10, 14, 21 days). The efficacy control tick was 0; 96.4 and 69%, respectively, at 21 days after treatment. On the 1st and 2nd milked after treatments, physiologic variables were evaluate and milk samples were collected to evaluate organoleptic properties in milk and yoghurt (negative control x phytotherapic treatment). Similar results were found with sensorial acceptance test of milk and physiologic variables. Key words: acaricide, milk organoleptic properties, phytotherapic, physiologic variables. Esta pesquisa foi conduzida com o objetivo de avaliar o efeito in vitro e in vivo do oleo de eucalipto (Corymbia citriodora) sobre o carrapato bovino (Rhipicephalus (Boophilus) microplus). Na experimentacao in vitro, foi utilizado o grupo controle negativo e oito concentracoes de oleo de eucalipto (0,5; 1; 2; 5; 10; 20; 50; 100%), em femeas ingurgitadas de carrapato. A eficacia de controle foi de 0; 30,5; 75,5; 91; 100; 100; 100; 100 e 100%, respectivamente. Para a experimentacao in vivo, foram constituidos tres grupos (controle negativo; oleo de eucalipto a 3, 5%--nivel estimado mediante analise de regressao, correspondendo a 95% de eficacia de controle do carrapato da pesquisa in vitro e amitraz a 0,025%), com dezoito vacas da raca Holandesa. Antes (media dos dias -3, -2,-1) e apos a aplicacao do produto (1, 2, 3, 5, 7, 10, 14, 21dias), foram contadas femeas ingurgitadas de carrapato. A eficacia de controle foi de 0; 96,4 e 69%, respectivamente, 21 dias apos o tratamento. Na 1a e na 2a ordenha apos a aplicacao dos tratamentos, foram avaliadas variaveis fisiologicas e coletadas amostras de leite para avaliar as propriedades organolepticas no leite e no iogurte (controle negativo x tratamento fitoterapico). O tes