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Abstract

Objective

To identify morphologic differences in ovaries from cows persistently infected with bovine viral diarrhea virus (BVDV) and determine ovarian cell types infected in these cows.

Design

A comparative study of ovaries in cattle persistently infected with BVDV and cattle not persistently infected with BVDV, using morphologic and immunohistochemical analysis.

Animals

6 postpubertal cows persistently infected with BVDV and 6 postpubertal cows not persistently infected with BVDV.

Procedure

Ovaries were compared morphologically by counting the number of normal structures present on 3 histologic sections taken from each ovary. Immunohistochemistry was accomplished, using an indirect, monoclonal antibody-linked, avidin-biotin-peroxidase complex procedure.

Results

Significant (P < 0.01) decrease in the number of tertiary follicles, graafian follicles, atretic follicles, and corpus hemorrhagicum/luteum/albicans was observed in cows persistently infected with BVDV. No difference in numbers of primordial or secondary follicles was observed. Immunostaining of BVDV antigen in luteal cells and macrophage-like cells was evident in ovaries from cows persistently infected with BVDV.

Conclusions

Cows persistently infected with BVDV appear to have significant morphologic changes in their ovaries that suggest reduction in normal ovarian activities. Furthermore, BVDV antigen can be identified in specific ovarian cell types in cattle persistently infected with BVDV.

Clinical Relevance

The changes observed may reduce reproductive performance in cows persistently infected with BVDV, and may be of importance when trying to salvage valuable genetic material from persistently infected cows through embryo transfer. It is yet to be determined whether similar findings are true in cows acutely infected with BVDV. (Am J Vet Res 1996;57:830–833)

Free access
in American Journal of Veterinary Research

Abstract

Objective

To compare recombinant transmissible gastroenteritis virus (TGEV) spike protein, (SP) R2-2, with attenuated live virus (ALV) vaccine in sows during late pregnancy.

Animals

13 TGEV-seronegative sows and their pigs.

Procedure

At prepartum weeks (PPW) 6 and 4, sows of groups 1 and 2 received ALV via the oral/intranasal (O/IN) route. At PPW 2, group-1 sows received ALV IM and group-2 sows received SPR2-2 IM. Group-3 sows received SPR2-2 IM at PPW 4 and ALV O/IN at PPW 2. Sows of group 4 (negative controls) were inoculated O/IN with mock-infected ST cell fluids at PPW 6 and 4 and IM with Sf9 cell lysates at PPW2 (n = 2), or IM with Sf9 cell lysates at PPW4 and O/IN with mock-infected ST cell fluids at PPW2 (2). Serum, colostrum, and milk samples were tested for antibody to TGEV, and a lymphoproliferative (LP) assay was done on blood mononuclear cells. Suckling pigs were challenge exposed with virulent TGEV.

Results

Sows of groups 1 and 2 had higher IgG and significantly higher antibody titers in colostrum; their pigs had significantly higher serum antibody titer. At challenge exposure of their pigs, LP responses of group-2 sows were significantly higher than those of sows in the other 3 groups. Mean pig mortality ranged from 43 (group 2) to 92% (group 4). Significant negative correlations were observed among litter mortality and sow LP response, colostral titer, and pig serum titer at time of challenge exposure.

Conclusions

In sows vaccinated twice with attenuated live TGEV, the recombinant SPR2-2 administered IM may be comparable to ALV administered IM as a booster. Vaccination failed to provide complete protection to suckling pigs after challenge exposure. (Am J Vet Res 1998;59:1002–1008)

Free access
in American Journal of Veterinary Research