The relationship between heat shock proteins and pregnancy loss in Holstein dairy cows

The objective of this was to consider relationship between heat shock proteins (HSP) with early embryo loss and pregnancy loss in Holstein dairy cows during summer season. Thirsty-two Holstein cows (with milk production> 30 Kg/d and 3.3±1.7 in parity) were selected. All cows were synchronized by G7G heat synchronization protocol. Blood samples were collected from all cows at d 16 after timed artificial insemination (TAI) to measure ISG15 gene expression. According to ISG15 results, 16 cows showed early embryo loss, then HSP gene family (HSP27, HSP40, HSP60, HSP70 and HSP 90) were compared between healthy cows and those with early embryo loss using t-test. Beta-actin gene was used as a housekeeping gene to compare results. Results showed ISG15 gene expression were greater in pregnant cows compared to early embryo loss (6.6 fold). Among HSP family gene considered in present study, HSP27 and HSP60 gene expression were similar between groups (p < 0.05). HSP40, HSP70 and HSP 90 genes expression were lower in pregnant cows compared to early embryo loss (4.7, 3.6 and 5.2 fold, respectively). In conclusion present study results showed among HSP family, there was an association among HSP40, HSP70 and HSP 90 genes expression and early embryo loss.