Abstract
This study aimed to describe the duration of inflammation after intrauterine infusion of polyvinylpyrrolidone-iodine (povidone-iodine, PVP-I), determine the effect of PVP-I infusion on the subsequent fertility, and evaluate the histopathology of the endometrium in dairy cows. In Experiment 1, 120 lactating clinically healthy Holstein-Friesian cows at 5 weeks postpartum (W5) were equally divided into three groups: intrauterine infusion of 2% PVP-I (PVP), saline (SAL), and no treatment (NTX). Endometrial cytology was performed daily from D0 (W5) to D7 to determine the percentage of polymorphonuclear cells (PMN%) in 44 of the 120 cows. All cows received timed artificial insemination at D17. In Experiment 2, 25 cows were randomly classified into sacrifice at 24 hr or 48 hr after 2% PVP-I infusion (PVP24 and PVP48), and 24, 48, 72, or 96 hr after SAL infusion (SAL24; SAL48; SAL72; SAL96), or no treatment (NTX). Histopathology was performed on the uterus of each cow. In Experiment 1, PMN% was greater in PVP (P<0.05) than in SAL and NTX, on D1, but decreased to a level similar to that of the other groups by D2. Conception rate was higher (P<0.05) in PVP cows compared to SAL and NTX cows. In Experiment 2, stratified columnar epithelium in the uterus disappeared in PVP24 and SAL24. The epithelium was regenerated in PVP48, SAL72, and SAL96, but not in SAL48. In conclusion, the results of the study suggest that PVP-I induces transient uterine inflammation, promotes regeneration of endometrial epithelial cells and improves fertility.