Hepatic alterations predispose to post-breeding endometritis in horses?

Abstract

The liver is an important organ for metabolism and homeostasis, affecting all systems and has a considerably impact of the individual's energetic, hormonal and immunomodulatory function. The occurrence of equine persistent post-breeding endometrits (PPBE), the third most common condition in horses and the most important in terms of fertility, is strongly associated with the animal's systemic health, a condition that can be measure from the liver profile. Therefore, the objective of this study is to determine whether liver alterations can predispose female horses to the occurrence of PPBE. To this end, this study will evaluate serum liver biochemistry, measuring: aspartate aminotransferase (AST), creatine kinase (CK), gamma glutamyl transferase (GGT), albumin (ALB) and total protein (PT) from the 48 cycles of 21 mares. The tests will be carried out on blood samples taken from the mares at two different times: immediately before (T0) and 48 hours (T48) after artificial insemination (AI). After blood collection, serum and plasma was obtained using the Vacutainer® system, centrifuged (600 xg/15 minutes), separated and stored in microtubes, identified and stored at -80°C in triplicates. The analyses will be processed out using an automatic biochemical analyzer (EXC 200) and commercial kits. According to the results obtained at T0, the cycles will be distributed into two groups: one with a liver profile within normal parameters (healthy) and the other with alterations in the liver profile (liver dysfunction). The uterus from each mare's estrous cycle was previously assessed for content, vascularization, microbiology and cytology at T0 and T48 to diagnose PPBE. The mares were inseminated with cryopreserved semen immediately after ovulation is achieved. To this end, the mares were monitored for follicular development and uterine conditions using transrectal palpation and ultrasound. When they have a follicle e 35 mm and morphoechogenicity > 3 (score 1-4), ovulation was hormonally induced. Pregnancy was diagnosed 14 days after AI, and when the diagnosis is negative, a new cycle was monitored. Positive results were confirmed at 35 and 60 days after AI. Statistical analyses will be carried out using the Statistical Analysis Systems program (SAS Version 9.4; SAS Institute; Inc., Cary, NC, USA). The data will be subjected to analysis of variance and group means will be compared using the Tukey test at a 5% significance level. As a result, we expect to find a correlation between liver findings and a higher incidence of PPBE.