Determination of the relationship between ovine ²-globin haplotypes and resistance to infection by Haemonchus contortus in Santa Inês, Texel and White Dorper breeds

Abstract

The growing consumer acceptance by products of ovine origin has driven sheep farming in Brazil, but although the national territory wastes a diversity of breeds in the most diverse biomes and regions of the country, production is not sufficient to meet the demand itself, as tonnes of sheep meat are imported annually. In this context, gastrointestinal nematodes (GIN) are the major bottleneck in this production system, especially the hematophagous species and cause of anemia, Haemonchus contortus, prevalent in Brazilian herds. The use of anthelmintics (AH) to control this NGI is no longer so effective, since its indiscriminate use has caused great resistance by the parasite, thus evidencing the need for alternative and efficient methods for its control. Thus, the present project aims to investigate the correlation of the different haplotypes of ovine ²- globin (Hb-AA, Hb-AB and Hb-AB) in the Santa Inês, White Dorper and Texel breeds, with different phenotypes of resistance and susceptibility to infection by H. contortus. The identification and selection of individuals and breeds more resistant to NGI can be considered a tool for integrated use of parasitic control. In this way, it is expected to contribute to the growth of the small ruminant production chain. by studying the association of ²- globine haplotypes, aiming to provide a future tool in the selection of H. contortus resistant sheep.