Monocyte function in pregnant and non-pregnant dairy cows.

Abstract

The main goal of this project was to investigate the differences in monocyte population and function between pregnant and non-pregnant dairy cows. Evaluating the differences in monocyte function may help to understand the immunosuppression of periparturient dairy cows. Blood was collected from three pregnant cows and four non-pregnant cows. The peripheral blood mononuclear cells (PBMCs) were incubated in six well plates for 3 hours, after which the monocytes were collected. Each cow was sampled twice, with 2-5 days in between. There was no difference in the total blood monocyte population as a percentage of the circulating PMBCs between pregnant and non-pregnant dairy cows, but pregnant cows showed a slightly increase in CD14+ cells as a percentage of the whole blood monocyte population. Dairy cows in late gestation (270 days) showed a decrease in MHCII expression on the CD14+ subpopulation compared with non-pregnant cows and cows in early gestation (120 days). This project showed that monocytes function of non-pregnant, early pregnant and late pregnant dairy cows are different. More research is needed to determine the magnitude of the differences and the consequences for cow health.