Institute of Animal Science (APTA-SAA), Rua Heitor Penteado, 56, Nova Odessa, São Paulo, 13380-011, Brazil.
Department of Biochemistry and Immunology, Ribeirão Preto Medical School, Ribeirão Preto, São Paulo, Brazil.
Exp Appl Acarol. 2019 Sep;79(1):99-106. doi: 10.1007/s10493-019-00413-0. Epub 2019 Sep 5.
Given the difficulties of controlling the tick Rhipicephalus microplus due to acaricide resistance, this study aimed to ascertain whether shearing could reduce infestation in cattle. 17 taurine cattle were sheared on the anterior third of one randomly selected side. Shearing was undertaken using a machine with a blade, leaving coats with a thickness of 1 mm. Subsequently, eight evaluations were performed once a week, counting adult females of R. microplus with a diameter > 4.5 mm on the anterior third of both sides (shorn and unshorn). The coat length was also monitored by taking five hair samples from each animal fortnightly (1, 15, 29, 43 and 57 days post shorn) from a central area of both shoulders (shorn and unshorn). The tick counts and hair length data were transformed for normalisation and were analysed using mixed models. The tick and hair length means were significantly higher for the unshorn side. Tick counts were significantly lower on the sheared side until the fifth evaluation, with the final three presenting no differences between the sides. The hair length was significantly lower for the sheared side during the five evaluations. We conclude that as the hair length increased, there was also an increase in the number of ticks on the sheared side. Although this method is not practical for large herds, it can be deemed an option in extreme conditions of tick infestation. In addition, the study reinforces the suggestion that the selection and/or use of cattle with shorter hairs may contribute to reduced tick infestation.
鉴于抗蜱螨剂的 tick Rhipicephalus microplus 难以控制，本研究旨在确定剪毛是否可以减少牛的感染。17 头 Taurine 牛被随机选择的一侧的前三分之一剪毛。使用带有刀片的机器进行剪毛，使毛发的厚度为 1 毫米。随后，每周进行八次评估，在两侧前三分之一处计算直径 > 4.5 毫米的 R. microplus 成年雌性蜱（剪毛和未剪毛）。通过每月从每个动物的两个肩部中央区域（剪毛和未剪毛）取五个毛发样本，监测毛发长度。蜱计数和毛发长度数据进行了归一化处理，并使用混合模型进行了分析。未剪毛侧的蜱和毛发长度均值明显更高。直到第五次评估，剪毛侧的蜱计数明显较低，最后三次评估两侧之间没有差异。在五次评估中，剪毛侧的毛发长度明显较低。我们得出的结论是，随着毛发长度的增加，剪毛侧的蜱数量也会增加。虽然这种方法对于大型牛群不可行，但在蜱严重感染的极端情况下可以考虑这种方法。此外，该研究证实了选择和/或使用毛发较短的牛可能有助于减少蜱感染的建议。
