In some areas of the country hit hardest by drought that culled cows but now are rebuilding herds, diseases like trichomoniasis need to be of top concern.
“As cows change hands, diseases move,” says Mac Devin, DVM, Boehringer Ingelheim. “We’ll be bringing cows back to states like Texas when the drought is over and we are growing more forages.”
Producers will be looking at the bottom line and a profit-robbing disease like trich can mean open and late-calving cows that are a drain on resources.
Soren Rodning, DVM, MS, Dipl. ACT, Auburn University, says a major factor in economic viability is reproductive efficiency. “A cow needs to produce a calf every year to be an economically viable member of the herd,” he says.
“Weaning rates affect ranch profits per brood cow. Calving distribution and when they are born over the season is important, too. Cows that calve early in the calving season such as day 0, will produce heavier calves at weaning. More pounds at weaning means more money on sale day.”
Infectious disease like trich, however, can negatively impact reproductive performance including abortion, early embryonic death, infertility and in some cases uterine infection. Cows that lose an early fetus may get bred on another cycle, but that then pushes their calving date later and results in a lighter calf at weaning time.
The disease is only transmitted when breeding is taking place, so tightening up the breeding season can help. “The shorter the breeding window, the less risk of disease transmission,” Devin adds. “Also, getting a pregnancy diagnosis allows us to divide those cows up to supplement according to stage in gestation. If we manage cows supplement-wise, protein-wise and with available forage, there are dollars to be saved by palpating and managing limited resources carefully.”
Trich is a tough cookie
A venereal disease spread by bulls to cows and caused by Tritrichomonas foetus, trich is an insidious disease that once anchored into a herd can be difficult to get out. “Infected cows are very damaging because they are hard to find and represent source of reinfection during the following breeding season and wreck efforts to control disease to the full extent,” Rodning explains. “Carrier cows can re-infect the bull battery.”
Veterinarians should talk with their producers about reproductive problems in the herd to gauge if trich might be an ongoing problem. Look at the herd’s history and records for:
- Open cows at preg check
- Early abortion
- Repeat breeding
- Late-term abortions
- Post-breeding uterine infection in some cows
- Strung-out calving season – cows are bred, lose the pregnancy and are bred again
Prevention and control
Prevention and control is two-fold – it needs to focus on the bulls and the cows. Using tested, virgin bulls is recommended, and older bulls should be tested. All bulls should be vaccinated with a trichomoniasis vaccine according to label directions.
Cows that are not pregnant or even late-pregnant should be culled if feasible, thus eliminating possible carrier cows. Heifers and cows should be vaccinated with a trichomoniasis vaccine according to label directions.
Other recommendations include:
- Avoid public grazing with other herds
- Maintain fences
- Use artificial insemination
- Have a short breeding season of 60-90 days
- Control animal movement in the herd
- Purchase young bulls (virgin) and heifers as replacement breeding stock
- Test bulls prior to purchase and/or prior to use and cull all bulls for humane slaughter that test positive for trich.
- Raise herd immunity through vaccination
- Reduce likelihood of infection or decrease level of exposure through herd management and good biosecurity.
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