Preventive and acaricid efficacy against Rhipicephalus microplus of abamectin association with fluazuron in artificially infested cattle

Abstract

The purpose of the research was to evaluate the acaricide and preventive efficacy of association abamectina 0.6% and fluazuron 3.0% in control of Rhipicephalus microplus in artificial infestations cattle. Were selected 12 cattle, that were kept stabled, crossbreeds Gir x Dutch, males, composing six animals per group. The control group animals received no treatment, while animals in the treated group received the formulation within the association in a single dose of 600 mcg of abamectin and 3 mg of fluazuron per Kg of body weight by route “pour-on”. The infestations on the control and treated groups were performed with 2500 larvae of Rhipicephalus microplus, in days -23, -21, -19, -17, -15, -13, -11, -9, -7, -5, -3, -2, -1and the collecting of engorged females it was performed in days -3 to +91, daily. To evaluation the preventive efficacy, the infestations continued in days +7, +14, +21,+28, +35, +42, +49, +56, +63, +70 and the collecting of engorged females followed daily until day +94. The efficacy against reinfestation was calculated on days +7, +14, +21, +28, +35, +42 +49, +56, +63 and +70. Statistical analysis between the average engorged females recovered between the groups control and treated showed that there was a significant difference (p≤0,05) for all subsequent time taken to treatment. The tested product showed acaricide effectiveness results of 0,00%; 6,81%; 62,64%; 85,11%; 98,38%; 97,38%; 96,84%; 97,63%; 98,14%; 97,32%; 97,54%; 98,11%; 99,22%; 97,93%; 98,13%; 96,78%; 96,17%; 99,05%; 98,57%; 98,59%; 97,23%; 96,10%; 99,31% respectively for the experimental days +1, +2, +3, +4, +5, +6, +7, +8, +9, +10, +11, +12, +13, +14, +15, +16, +17, +18, +19, +20, +21, +22, +23 for treated group. The mean of the efficacy over the 23 days after treatment was 97,8%. The preventive effectiveness results of 98,12%; 98,68%; 98,36%; 97,88%; 96,76%; 96,45%; 96,84%; 97,03%; 95,36% and 87,07% respectively for the experimental days +7, +14, +21, +28, +35, +42, +49, +56, +63, +70. The association abamectin 0.6% with fluazuron 3.0% was effective against reinfestation by larvae of R. microplus until day 60 after treatment.