Use of farrowing rate as a measure of fertility of boars.

The first 100 single-boar services of 140 boars were analyzed to determine whether the farrowing rate resulting from initial services predicted the farrowing rate of subsequent services. The data were analyzed for the influence of parity, number of matings per estrus, season of service, and interaction of these variables on farrowing rate. Sow parity influenced farrowing rate.

Presence of antibodies to the major surface glycoprotein of Trypanosoma cruzi amastigotes in sera from Chagasic patients.

The surface of amastigote forms of Trypanosoma cruzi is covered by a stage-specific glycoprotein, Ssp-4. We show that Y strain-derived Ssp-4 is recognized by antibodies in sera from Chagasic patients. All 51 sera reacted with the surface of amastigotes by indirect immunofluorescence assays and immunoprecipitated Ssp-4.