Bovine viral diarrhea virus: Its effects on estradiol, progesterone and prostaglandin secretion in the cow

Bovine viral diarrhea virus (BVDV) is a major cattle pathogen responsible f or a spectrum of symptoms, including reproductive failure. This study was d esigned to establish the effects of BVDV infection on estradiol, progestero ne and PGF2alpha secretion in the cow. Seven BVDV-free cows were challenged with non-cytopathogenic BVDV (strain Pe 515: 5x10(6) tissue culture infect ed dose(50)) so that peak viremia occurred during the initial phase of lute al development in a synchronized estrous cycle. Ovulation was also synchron ized in 7 sham-infected animals. Within 2 wk of inoculation, viremia, leukopenia and serum neutralizing anti bodies were recorded in all of the BVDV-infected cows but not the sham-infe cted animals. Between Day 4 and Day 9 post estrus the BVDV-infected cows ha d significantly (P<0.01) lower plasma estradiol levels than the sham-infect ed animals. However, the BVDV infection did not alter rectal temperatures, plasma progesterone concentrations or PGF2alpha secretion 17, 18 and 19 d p ost estrus. These data highlight a potential causal link between BVDV virem ia, endocrine dysfunction and poor fertility in the cow. (C) 1999 by Elsevi er Science Inc.