Like waking up from a terrible nightmare, our vaccination ordeal has finally come to an end.

Last May, we finished vaccinating a group of bred heifers in preparation for turning them out to pasture.

Of the eleven heifers vaccinated, five were moved into the dry cow group. The other six we would be bringing over to pasture the next week.

The vaccination was administered uneventfully, and the close-up heifers cooperated very nicely during the move from the heifer yard to the dry cow pen.

Four days later, we found Lindy's aborted heifer calf. We figured it was due to her move into the dry cow group, chalked it up to bad luck, and tried to decide what to do with Lindy. She was only due on the Aug. 18. We didn't know if we should try to milk her - and hope her milk would come in - or just try to get her bred back as soon as possible. We chose to milk her, with the thought that we could always dry her up if her milk didn't come in.

Then, on May 13 we found Daphne's and Dreamer's calves. At that point, we called the vet. We collected the heifers' aborted bull calves, pulled blood from the heifers and sent everything down to the University of Minnesota's Veterinary Diagnostic Laboratory, hoping the team down there could give us some answers to all of the questions we were asking.

In the meantime, Demeter aborted on May 15. Another bull calf.

Within a few days it became apparent Jolene was going to lose her calf as well. Being the furthest along, her bull calf almost looked mature enough to live when it arrived on May 18.

At one point Glen said, "This really sucks, but I'd really be mad if all these aborted calves were heifers."

We chose to milk Daphne, Dreamer, Demeter and Jolene as well. Their milk came in slowly, but it came in. Without full udder development and none of the calming that comes with becoming a mother, these five heifers were firecrackers. At times, it hardly seemed worth dealing with all the trouble.

We kept our chins up, though. Until Grace aborted, too. That's when I lost it. She's the daughter of my Ginny cow and, therefore, one of my favorite red heifers. We had some trouble catching her in heat, so when she finally settled, I had been ecstatic.

While walking past the heifer yard one morning, the way she was just standing there alone by the bale feeder struck me as odd, and a feeling of dread began to creep over me. As I got closer, I saw she was standing there guarding her tiny calf, still floating peacefully in its amniotic sac.

I collected her calf and placenta. I was still standing over the sink examining the tiny bull calf when Glen came into the milkhouse. My tears erupted like a volcano. Somehow I had been keeping my cool with the other abortions, but Grace's was more than I could handle. She was only four-and-a-half months pregnant when she lost the calf and it was clear we would not be milking her.

The fetuses and placentas from the last three abortions were sent in for testing as well. By the end of May we had results: all six of the abortions were caused by the infectious bovine rhinotracheitis (IBR) virus.

At that point we started looking at the vaccine the heifers had received just prior to aborting. There had been no clinical signs of IBR in any of our animals, and our veterinarian thought it was just too unlikely that so many heifers would abort at the same time from exposure to a field strain of IBRV.

The heifers had been vaccinated with a five-way vaccine designed for use in pregnant cattle. They received their first dose in mid-April; the aforementioned dose was the second in the two-dose series.

After contacting the vaccine's manufacturer, a joint investigation was started to determine if the vaccine had indeed caused the heifers' abortions.

We provided the serial number from the bottle of vaccine used to vaccinate the heifers. (Our record-keeping system for vaccinations includes unfolding the vaccine box and writing the name of each heifer or cow who receives a dose from that bottle on the inside of the box. Ironically, we had just started this system at the beginning of last year. The system proved its value, though; without it, we would have had no way to trace the vaccine.)

In addition, all of the other heifers in the original group were kept home from pasture until their pregnancies were re-confirmed and blood samples were collected for testing.

We spent the rest of the summer and fall waiting for a report from the pharmaceutical company who manufactured the vaccine. Each month our veterinarian would call and tell us we still didn't have results from the investigation.

Finally, in December, we had news. The investigation showed no link between the strain of IBRV that caused the heifers' abortions and the strain of IBRV contained in the vaccine. We still believe the vaccine played a role in the abortions, but from the pharmaceutical company's perspective, the investigation is over.

And, so, we are left with unanswered questions - What really did happen with those heifers? How can we prevent something like this from happening in the future? - but we learned several important lessons.

First, impeccable record keeping is more important than even we could have known prior to this ordeal. Our herd health folder in the barn is now filled with flattened vaccine boxes bearing the names of the vaccines' recipients.

Second, we no longer vaccinate pregnant animals with killed vaccines. Although it requires more management, we now vaccinate only open cows and heifers with a modified live vaccine.

Third, we learned the importance of reporting adverse reactions to vaccines and other medicines. The Center for Veterinary Biologics (CVB) at USDA's Animal and Plant Health Inspection Service (APHIS) keeps reports of adverse events related to veterinary biologics (e.g. vaccines). These reports are analyzed for the possibility of a product deficiency. However, if no reports are ever made, the USDA won't ever question the efficacy and safety of a product. I can't tell you how many times - after hearing about our vaccination experience - someone said to us, "Oh yeah, we had a problem with that vaccine..." Unfortunately, it became clear to us that several farmers have had problems with one vaccine, drug, or another, but none of those events were reported.

Of even more importance is reporting the event to the pharmaceutical's manufacturer. The manufacturer of our vaccine had "never, ever" had a case like ours reported. APHIS requires the event first be reported to the manufacturer and then to the CVB.

We hope that by sharing our story, others will learn from our experience, and should they ever find themselves in a similar situation, they'll be better prepared.

In the end, our ordeal wasn't the end of the world. We figure we lost about $7,000 between the sub-par lactations of the heifers we milked, the lost calves, and Grace's extra time as a heifer, but money isn't everything. The still-pregnant heifers made it out to pasture; they're calving in now and doing very well. The aborted heifers bred back right away, with the exception of Grace (it took awhile for her to come into heat), and we're looking forward to their second lactations.