The role of porcine parvovirus (PPV) in inducing reproductive failure in swine has been extensively documented. However, information is not available as to the risk of ppv transmission by embryo transfer. Using the polymerase chain reaction (PCR) technique, PPV-specific DNA was detected in association with 4-day-old porcine embryos incubated in vitro in the presence of NADL-8 strain of PPV, despite attempts to rid the embryos of virus by either washing or treatment with pronase or trypsin. The presence of PPV in embryos collected from acutely infected swine was not detected by PCR, although PPV DNA was detected in the proximal portion of the reproductive tract during the early stages of infection. Viral-specific nucleic acid was not detected in embryos transferred from infected donors to seronegative recipients and retrieved and assayed on the 15th and 32nd days of gestation. Results of the use of PCR to detect PPV associated with swine female reproductive tract and embryos ascribe minimal risk to the transmission of PPV to seronegative recipients through embryo transfer.

Equine endometria representative of Kenney's categories I, II, and III were incubated in vitro with phosphate buffer, Streptococcus pneumoniae, or S zooepidemicus. Endometrial tissues from mares in estrus and diestrus were first categorized according to Kenney's classification, then were tested for adherence of S pneumoniae and S zooepidemicus to the epithelia. Bacteria were not observed when the endometrial tissue was incubated with phosphate buffer or S pneumoniae. There was no statistical difference in attachment of S zooepidemicus to endometrial tissue from mares in estrus or diestrus if endometrial classification was ignored. However, bacterial attachment was significantly (P less than or equal to 0.05) higher in category III endometrium during estrus.

The microscopic brush border membrane adherence assay was used to determine resistance (nonadherence) and susceptibility adherence) of Chinese pigs (n = 289) to the K88ac+ strain of Escherichia coli-mediated disease. This study estimates prevalence of resistance to diarrheal disease in multiple family lines (no common ancestry for a minimum of 3 generations) for the Chinese Meishan, Fengjing, and Minzhu breeds. Results of in vitro assays indicate that pigs of the Meishan breed are highly resistant (nonadherent) to K88ac+ E coli-mediated disease. The gene conferring susceptibility to K88ac+ E coli-mediated disease exists at low frequency in pigs of the Minzhu breed. Minzhu-type (crossbred) pigs of both phenotypes (susceptible and resistant) were identified in ratios consistent with a 1-locus gene model. Given that all susceptible pigs were from 1 site, frequency of susceptibility within this Minzhu population is estimated at 8%. Inheritance within the Fengjing breed is still unclear because a weakly adherent phenotype, as well as the resistant phenotype, was identified. The weakly adherent phenotype was observed in pigs derived from multiple family lines. Expression of the weakly adherent phenotype in terms of susceptibility to disease is not known at this time.