Sexual behavior of castrated boars treated with prostaglandin F2α

Abstract

The objectives were to test the hypothesis that exogenous prostaglandin F(2alpha) (PGF(2alpha)) temporarily restores sexual behavior of castrated boars, and to evaluate effects of PGF(2alpha) on serum hormone concentrations. At 35 d after castration, nine lean-type adult boars were randomly assigned to three treatments in a 3x3 latin square (with three replicates). Treatments were three doses of PGF(2alpha) doses (0, 10, and 20mg) and three periods of treatment, with 5 d between each period. Serum testosterone (T) concentrations were non-detectable at the start of the experiment. Serum concentrations of estradiol (E2), LH, prolactin (PRL), and cortisol were unaffected (P>0.05) by PGF(2alpha) treatment. The interval from treatment to ejaculation in boars treated with 10mg (758s) or 20mg (660s) PGF(2alpha) did not differ, but were different (P < 0.05) from control boars (>1 800s). Ejaculation duration and false mounts differed (P < 0.05) between control boars and boars treated with 10 or 20mg PGF(2alpha). In conclusion, PGF(2alpha) treatment did not change serum concentrations of T, E2, LH, PRL, or cortisol, but restored sexual behavior. This restoration may have been due to an effect of PGF(2alpha) directly in specific areas of the brain, or indirectly via release of other hormones that stimulated areas in the brain that affected sexual behavior.