“What Were They Thinking?”

BY JOY REZNICEK SUNDBECK

WE RECEIVED A CALL FROM A CUSTOMER WHO HAD PREGNANCY CHECKED HIS COWS. ALL OF HIS COWS WERE OPEN. HISTORICALLY HE HAD EXPERIENCED HIGH CONCEPTION RATES OVER THE YEARS USING MULTIPLE TOWN CREEK FARM BULLS. Reproductive failure of his cows prompted his vet to recommend testing his bull – for everything. Turns out, the bull passed his semen test with flying colors and tested negative on every disease from Trich to Johnes.

His vet then honed in on the cow herd. Whole herd testing revealed the culprit as Leptospirosis (Lepto). Our customer ultimately divulged that he had not taken the time to give annual cow herd vaccinations.

Another incident recently unfolded. A producer questioned fertility in his Town Creek Farm bulls when too many cows of his cows were open after his fall and spring breeding seasons. The producer contacted me to alert us of the situation. I encouraged him to semen test his bulls. He semen tested both bulls and they passed breeding soundness exams. Following up, I asked if his cowherd was on schedule with annual vaccinations, specifically Lepto. He replied, “Historically, yes.” But admitted that he skipped vaccinating his cows this year. He only vaccinated his heifers.

He went on, “I just had a long in-depth conversation with my vet regarding Lepto.” Our customer presumed he was not at risk for Lepto, even without protection, as he had not purchased or added a single female to his herd in over 20 years.

His vet speculated without annual Lepto protection, Lepto was the only possible disease that could invoke reproductive failure. Reproductive failure is an all-encompassing term meaning cows lose calves during pregnancy or they fail to get pregnant.

“Leptospirosis is endemic everywhere here,” says Dr. Jim Brett of Mississippi State University. “We see it transmitted through rodents, mice and rats, and also wildlife. So, if you have stored feed, and you have rodents, you are at risk of having Lepto.”

“If you skip a vaccine in our environment, you are putting your herd at risk,” cautions Dr. Brett. “It depends on the pathogens in your area on your farm. I’ve seen cattle operations skip a vaccine of clostridial diseases and then lose calves from blackleg.”

Transmission from one infected cow to another healthy cow with Leptospira serovar (Hardjo) is efficient, and the infection rate can be very high in an unvaccinated herd. It is a complicated bacterial disease commonly associated with abortions, stillbirths, premature births, and infertility in cattle.

Lepto is most common in moist climates. It is caused by spiralshaped bacteria (spirochetes) that affect both animals and humans. Often present in wildlife populations, including rats and mice, they survive in surface water, stagnant ponds, streams, or