THE RELATION BETWEEN GENETICS AND TICK RESISTANTE IN DAIRY COWS: A LITERATURE REVIEW

Abstract

The dairy cattle’s farming is considered essential to the Brazilian economy. However, the occurrence of diseases caused by ticks of the genus Rhipicephalus [Boophilus] microplus may cause direct damage to dairy cows, resulting in low production yields. These parasites are controlled with chemicals agents, but due to the development of parasite resistance and intoxication, other methods, such as genetic resistance, are being studied. The main of this study was to analyze and describe, through a literature review, how genetic improvement can contribute to increasing the resistance of dairy cows to tick infestation. Through a search of the Google Scholar, Scielo, and PubMed databases, 30 scientific studies from the last 20 years that addressed the proposed topic were selected for this review. At the end, it was concluded that genetic improvement is an effective option for parasite control in dairy cattle farming, and can be achieved either by crossing genetically resistant breeds (zebu) with those most susceptible to tick development (European) or by genomic selection for grazing only the most resistant breeds, reducing costs in the purchase of chemical agents, contributing to the environment, reducing the chances of poisoning and helping to reduce the development of tick species with bigger resistance.