Reproduction Abstracts

Dairy herd fertility is in decline and poses a significant economic problem, with associated animal welfare concerns. One factor that may contribute to this decline is exposure to environmental chemicals (ECs) some of which have endocrine disrupting activity and have been linked to declining fertility in other species. We hypothesised that ECs are present in bovine ovarian tissue at levels able to perturb luteal development and function. The tissue content of DEHP and a panel of PCB congeners was determined in abattoir-derived bovine ovaries (n=4), following tissue extraction and gas chromatography linked to mass spectrometry (GC–MS). Both DEHP and several PCBs were detected in bovine ovarian tissue. DEHP and PCB153 were detected well within the analytical range (1.51 μg/g and 0.039 ng/g respectively), whilst mean concentrations of PCBs 52, 101, 118, 138, 153 and 180 were just above the detection limit of 0.02 ng/g. Due to the importance of angiogenesis in luteal growth and subsequent progesterone secretion, the dose-dependant effect of DEHP was further investigated utilising a bovine luteal angiogenesis culture system (n=3). DEHP did not alter the degree of luteal endothelial cell network formation or progesterone production over 9 days in culture. In conclusion, ECs are present in the bovine ovary and DEHP, at environmentally relevant concentrations, does not appear to influence luteal angiogenesis or steroidogenesis in vitro. Other individual and combined ovarian ECs are under investigation.

Robert Thompson was supported by the SRF vacation scholarship.