Direct genomic value daughter pregnancy rate and services per conception are associated with characteristics of day-16 conceptuses and hormone signaling for maternal recognition of pregnancy in lactating Holstein cows

Objective: Our objective was to test the hypothesis that sorting Holstein dairy cows with high direct genomic value for daughter pregnancy rate (DGV-DPR) and low services per conception records improves interferon tau production and endometrial signaling for maternal recognition of pregnancy.Materials and Methods: Lactating Holstein cows (n = 86) were sorted by DGV-DPR into high-and low -fertility groups with the Clarifide (https://www.zoetisus.com/ animal-genetics/dairy/clarifide/clarifide.aspx#) DNA test and low and high services per conception from farm records. High-fertility nonpregnant (NP) cows were not inseminated (n = 7) and served as controls. High-fertility pregnant (HP; n = 7) and low-fertility pregnant (LP; n 6) cows received timed AI. Conceptuses, uterine flushings, endometrial biopsies, and peripheral blood mononuclear cells were collected on d 16 of pregnancy or the estrous cycle.Results and Discussion: Conceptuses from HP cows were longer (P < 0.05) than those from LP conceptuses. Concentrations of interferon tau in uterine flushings were greater (P < 0.05) in HP compared with LP and NP cows, positively correlated with DGV-DPR (r = +0.68; P 0.05), and negatively correlated with services per conception (r = -0.59; P < 0.05). Endometrial ISG15 mRNA and protein were upregulated (P < 0.05) in HP compared with NP. Low-fertility pregnant cows had intermediate en dometrial levels of ISG15 mRNA between HP and NP, and ISG15 protein tended (P < 0.10) to be greater in LP compared with NP cows. This tendency was also observed for increased ISG15 in HP compared with NP in peripheral blood mononuclear cells.Implications and Applications: Results supported the hypothesis and provided evidence to suggest that Holstein cows with greater DNA-based DGV-DPR values and fewer services per conception have increased conceptus length and enhanced signaling for maternal recognition of pregnancy.