Resistência contra ectoparasitas em bovinos da raça Crioula Lageana e meio-sangue Angus avaliada em condições naturais

Abstract

Pesq. Vet. Bras. 34(2):141-146, fevereiro 2014 141 RESUMO.-Este trabalho foi desenvolvido com o objetivo de avaliar a resistência aos ectoparasitas em bovinos jovens da raça Crioula Lageana e meio-sangue Angus em condições naturais. Foram utilizados 10 machos castrados em cada grupo, recém desmamados (6-8 meses) e mantidos sob as mesmas condições de manejo, em pastagens cultivadas de inverno e verão, no município de Monte Castelo -SC, sofrendo infestação natural por ectoparasitas. A cada 28 dias, fêmeas de carrapatos (Rhipicephalus (Boophilus) microplus) com tamanho acima de 4 mm foram quantificadas nos dois lados do corpo de cada animal, bem como os nódulos com larvas de Dermatobia hominis. A espessura da capa do pelame foi também avaliada a cada coleta e os animais foram classificados quanto à coloração do pelame. Os animais da raça Crioula Lageana foram mais resistentes às infestações por D. hominis e R. microplus. Não houve diferença entre a disposição de carrapatos e bernes conforme os lados direito e esquerdo dos animais. Os animais de pelagem escura albergaram a maior porcentagem de ectoparasitas nos grupos avaliados. This study was carried out to evaluate the breed resistance against ectoparasites infestations in Crioula Lageana and crossbred Angus male calves under natural condition. Ten weaned and neutered male calves (6-8 months) of each group were kept together in winter and summer pastures in Monte Castelo, Santa Catarina State. Every 28 days, female ticks (Rhipicephalus (Boophilus) microplus) more than 4 mm long were counted on the right and left side of the body of each animal, as well as the D. hominis nodules. Coat thickness also was measured at each sampling and all animals were classified according coat color. Crioula Lageana group was less infested by D. hominis than crossbred Angus in five times and by ticks in the infestation peak (P<0.05). There were no differences in the distribution of the ticks and grubs between animal body sides. Dark-haired animal in both groups were the most susceptible.

Genome-wide association studies for tick resistance in Bos taurus × Bos indicus crossbred cattle: A deeper look into this intricate mechanism

“…Breeds of Bos indicus are genetically more resistant to ticks than Bos taurus due the presence of naturally selected genes throughout their evolutionary process (Ibelli et al, 2012;Ayres et al, 2015). Genetic variability for bovine tick resistance has been reported (Cardoso et al, 2014), showing potential for the improvement of this trait. According to Walker (2011), individual ability of cattle to acquire tick immunity is hereditary.…”

Reactive oxygen species and evaluation of the quality of carcasses and beef meat from cold storage slaughterhouses located in the Federal District and Surroundings (Brazil)

“…After the desensitization, bleeding and skinning procedures, pieces of approximately 3.0 cm of the extensor carpi radialis muscle were collected and frozen in liquid nitrogen for the subsequent quantification of reactive oxygen species. Next, the number and location of hematomas in the carcasses were evaluated, dividing them into regions proposed by the methodology by Cardoso et al, [19].…”

One Health Approach to Identify Research Needs on Rhipicephalus microplus Ticks in the Americas

“…The incorporation of tick resistant cattle is a feasible tool to reduce the annual frequency of acaricide treatments. The genetic basis of host response variation to tick infestation within and between breeds is a widely known phenomenon [ 76 , 77 , 78 , 79 , 80 , 81 , 82 , 83 , 84 , 85 , 86 ]. In this sense, Bos indicus cattle are generally considered to be more resistant to ticks than Bos taurus breeds, and particular breeds from Africa (e.g., Afrikander, Nguni and N’Dama) and America (e.g., Colombian Creole breed Romosinuano, Brazilian Creole Lageano, Argentine Creole Cattle) have also shown high levels of resistance to ticks [ 77 , 78 , 81 , 83 , 85 , 86 ].…”

“…The genetic basis of host response variation to tick infestation within and between breeds is a widely known phenomenon [ 76 , 77 , 78 , 79 , 80 , 81 , 82 , 83 , 84 , 85 , 86 ]. In this sense, Bos indicus cattle are generally considered to be more resistant to ticks than Bos taurus breeds, and particular breeds from Africa (e.g., Afrikander, Nguni and N’Dama) and America (e.g., Colombian Creole breed Romosinuano, Brazilian Creole Lageano, Argentine Creole Cattle) have also shown high levels of resistance to ticks [ 77 , 78 , 81 , 83 , 85 , 86 ]. Because the tick burden diminishes with the increasing percentage of B. indicus genes in synthetic cattle breeds, the incorporation of more resistant cattle to tick infestations should be considered in areas infested with R. microplus where British breeds of cattle are still dominant, or cattle with a dominant composition of British genes, which are highly susceptible to R. microplus infestations.…”