INTRAUTERINE FLUID ACCUMULATION IN ESTROUS MARES

Intrauterine fluid (IUF) was collected using a tampon from mid-oestrou s mares (n=57) with and without ultrasonically detectable accumulation s of free intraluminal fluid. Bacteria were cultured and neutrophils c ounted from all samples (n=57). Total protein concentration, trypsin-i nhibitor capacity (TIG), and plasmin, 8-glucuronidase (B-Gase) and N-a cetyl-beta-D-glucosaminidase (NAGase) activities were determined in 27 IUF samples. The motility of spermatozoa in the presence of IUF, IUF extended with Kenney's medium (1:1) and Kenney's medium alone was anal ysed in 9 samples using a Hamilton-Thorn motility analyser. Thirty-fiv e mares were inseminated immediately after collection of IUF, and ever y second day until ovulation. Embryos were recovered nonsurgically 6 d ays after ovulation. After embryo transfer, fluid accumulations were r ecorded during oestrus and an endometrial biopsy specimen taken (n=53) . In the beginning of oestrus, fluid accumulations were detected in 39 % (22/57) of mares, while on the day when IUF was collected, fluid acc umulations were observed in 26% (15/57) of mares. The fluid was anecho genic, and in 80% of the mares located in the uterine body. None of th e mares exhibited cytological or bacteriological evidence of acute end ometritis. Total protein concentrations, TIC and B-Gase activities in IUF were statistically significantly lower in mares with fluid accumul ations (n=14) than in mares without fluid accumulations (n=13) (p<0.01 ). The addition of undiluted IUF to extended semen significantly reduc ed total and progressive motilities, path velocities and percentages o f rapid spermatozoa (p<0.05) in vitro. On endometrial biopsy, fibrosis was found to be more prominent (p=0.025) in mares with fluid accumula tions (n=9) than in mares without (n=44). It was concluded that anecho genic fluid accumulations during oestrus were associated with composit ional changes in IUE Although IUF had negative effects on spermatozoal motility in vitro, the presence of fluid accumulations at the time of insemination did not affect embryo recovery rates.