Ferraz da Costa Maria do Socorro, Guimarães Marcos Pezzi, Lima Walter Dos Santos, Ferraz da Costa Ana Julia, Facury Filho Elias Jorge, Araujo Ricardo Nascimento
Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Bloco i4, Sala 177, Avenida Antonio Carlos 6627, Pampulha, 31270-901 Belo Horizonte, MG, Brazil.
Departamento de Clínica de Ruminantes, Escola de Veterinária, Universidade Federal de Minas Gerais, Avenida Antonio Carlos 6627, Pampulha, 31270-901 Belo Horizonte, MG, Brazil.
J Vet Med. 2014;2014:759854. doi: 10.1155/2014/759854. Epub 2014 Oct 8.
The aims of this study were to evaluate the seasonal variation and frequency distribution of Rhipicephalus (Boophilus) microplus, Haematobia irritans, and Dermatobia hominis on crossbred heifers under field conditions in the northeast of Minas Gerais state, southeastern Brazil. From November 2007 to September 2009 (23 months), 40 heifers aged 16.6 ± 2.4 months were divided into groups A (1/4 Holstein × 3/4 Gir) and B (1/2 Holstein × 1/2 Gir) and had the monthly infestation estimated along with the climatic conditions. The mean maximum and minimum temperatures were 28.5 and 19°C, respectively. The ectoparasites were present on animals in all months of the year. The levels of ticks on the animals were low (3.0 ± 0.2 ticks/animal), with the highest density in midwinter. The temperature was the climatic factor that most influenced the tick levels. The population of H. irritans (13.9 ± 0.3 flies/animal) and D. hominis (1.5 ± 0.2 larvae/animal) on heifers was more influenced by rainfall and exhibited two population peaks during the year. 1/2 Holstein heifers harbored significantly more H. irritans and D. hominis than 1/4 Holstein heifers. The results are discussed considering the most appropriate periods to apply ectoparasiticides and the genetic make-up of the animals.
本研究的目的是评估在巴西东南部米纳斯吉拉斯州东北部的野外条件下，微小扇头蜱（牛蜱属）、血蝇和人皮蝇在杂交小母牛身上的季节变化和频率分布。从2007年11月至2009年9月（23个月），将40头年龄为16.6±2.4个月的小母牛分为A组（1/4荷斯坦×3/4吉尔牛）和B组（1/2荷斯坦×1/2吉尔牛），并结合气候条件对每月的寄生虫感染情况进行估算。平均最高温度和最低温度分别为28.5℃和19℃。全年各月动物身上均有外寄生虫。动物身上蜱的数量较低（3.0±0.2只/动物），在冬季中期密度最高。温度是对蜱数量影响最大的气候因素。小母牛身上血蝇（13.9±0.3只/动物）和人皮蝇（1.5±0.2只幼虫/动物）的数量受降雨影响更大，且在一年中出现两个数量高峰。1/2荷斯坦小母牛身上的血蝇和人皮蝇数量显著多于1/4荷斯坦小母牛。结合使用杀外寄生虫剂的最合适时期和动物的基因组成对结果进行了讨论。
