A pilot study of elevated abortion and stillbirth ratios in cattle in the foothills of the Eastern plains of Colombia

Abstract

Health and production monitoring of around 80 commercial cattle enterprises in the foothills of the Eastern plains of Colombia showed that abortion and stillbirth ratios exceeded 0.10 in about one-quarter of the farms. A case-control approach comparing three farms with elevated abortion/stillbirth ratios (at least 0.10) with six farms with low ratios (0.03 or less) was adopted for an initial appraisal of the possible role of various infectious as well as non-infectious causes. The abortion histories and estimates of the age of the aborted fetuses were compiled from the available records. Management practices and environmental variables were assessed using a questionnaire. Laboratory examinations were carried out on a sample of 30 female cattle from each of the nine farms (serology for Brucella abortus and Chlamydia psittaci, five serovars of Leptospira interrogans, and infectious bovine rhinotracheitis virus ) and the breeding bulls (isolation attempts of Trichomonas fetus, Campylobacter fetus, and Haemophilus somnus). The prevalence of antibodies to Chlamydia psittaci was significantly lower and the seroprevalence of Leptospira interrogans serovar hardjo was significantly higher on the case farms while no distinct differences were found for any of the other variables examined. On two of the case farms, 28.3% of the cattle had titers of at least 1:400 to serovar hardjo as opposed to 2.2% of cattle on the control farms ( P < 0.01). On these two farms 36% ( 10 28 ) of the abortions occurred in the second trimester of gestation while on the third case farm most abortions occurred around term at the end of the dry season.