Early pregnancy diagnosis in cattle through the expression of interferon-tau stimulated genes in neutrophils

Abstract

The early pregnancy diagnosis may allow a reduction in the interval of inseminations, resulting in a shorter calving to first service interval, a reduction in the calving interval and a positive impact on the profitability of the livestock production system. In the present study, the central thesis is based on the fact that the bovine concept can stimulate transcripts in immune cells that would serve as biomarkers in the blood and could be detectable at the beginning of gestation, thus allowing the development of an early method (before 21 days post-insemination) and innovative pregnancy diagnosis in cattle. The main objective of this study was to develop a laboratory method for the diagnosis of gestation by quantifying the abundance of interferon tau-stimulated genes (ISGs) in polymorphonuclear immune cells (PMNs; neutrophils), which are more sensitive to interferon stimulation than mononuclear immune cells (PBMCs, monocytes, lymphocytes). The first stage of the study will consist in the characterization and comparison of ISG expression in PBMCs and PMNs in the initial period of gestation (Days 12 to 20 post-insemination) in pregnant and non-pregnant heifers, and later evaluation of the viability of using the technique as early pregnancy diagnosis. In the second stage, the accuracy of the gestational diagnosis will be analyzed by quantifying the expression of ISGs in PMNs. Through the results obtained, it is expected that the new knowledge and innovative methods serve as a basis for the development of techniques for dairy and beef farming, aiming the progress of animal production. (AU)