Steroid concentrations in follicular fluid of sows treated with dexamethasone

The effect of injecting the glucocorticoid, dexamethasone (DXM), on ovarian follicular development and steroid concentrations in the sow was investigated. Control sows were injected with 1 ml physiological saline solution i.m. and treated sows were injected with 30 μg kg−1 bodyweight DXM i.m.; both treatments were administered every 12 h from Days 9 to 14 of the estrous cycle. Two experiments were conducted. In Experiment one, follicular fluid was collected and pooled from sows under sodium pentobarbital anesthesia on Days 5, 8, 12, 15, 17 and 19 for control animals and on Days 12, 15, 17, 19 and 26 (Day 5 of next cycle) for DXM-treated animals. Sows given DXM subsequently exhibited poorly defined signs of estrus. On Day 26 their ovaries possessed numerous small cyst-like follicles but few corpora lutea compared to control ovaries that contained corpora lutea and newly developing follicles on Day 5. Androstenedione and estradiol concentrations were lower (P < 0.05) in follicular fluid from DXM-treated sows on Day 12. Progesterone concentrations varied through the cycle but, like testosterone and estrone values, did not differ significantly between treatments.