The importance of seminal plasma on the fertility of subsequent artificialinseminations in swine

Yorkshire x Landrace sows and gilts were used in a 3 x 2 factorial arrangem ent of treatments to determine the effect of uterine inflammation induced b y either killed spermatozoa (KS) or bacterial lipopolysaccharide (LPS) on t he fertility of a subsequent, optimally timed Al. Estrus was detected with a mature boar twice daily. Twelve hours after the first detection of estrus , females received intrauterine infusions of an inflammatory stimulus consi sting of a 100-mL dose of extender containing 3 x 10(9) KS (n = 40), 20 mu g of LPS (n = 40; positive control) or extender alone (n = 40; negative con trol). An insemination was performed 12 to 18 h later with 3 x 10(9) motile spermatozoa (i.e., fertile Al) suspended in either 100 mt of seminal plasm a (SP; n = 60) or extender replenished with of estrogens (5 mu g of estradi ol-17 beta, 4.5 mu g of estrone sulfate, and 2 mu g of estrone; n= 60). Tra nscutaneous ultrasound was performed at the time of fertile Al and again 24 h later to detect the presence or absence of preovulatory follicles. A fer tile Al performed within 24 h before ovulation was considered optimal. Conc eption (CR) and farrowing rates (FR) were greater in females that received a fertile AI diluted with SP compared with extender (P < .01), and there wa s a significant (P < .05) treatment x fertile AI dilution medium interactio n for both CR and FR. Females that received a fertile Al 12 h after infusio n of extender had similar CR and FR regardless of fertile AI dilution mediu m. After inducing an inflammatory response with either KS or LPS, CR and FR were higher in females that received a fertile Al diluted with SP compared with fertile AI dilution with extender (P < .05). The effects of treatment and Al dilution media and their interactions were not significant for litt er size in females that farrowed. These results show that the fertility of a subsequent Al can be impaired when semen is deposited into an inflamed en vironment created by an earlier Al, and this impairment was offset by inclu sion of SP in the subsequent insemination.