Specialist: Partner vaccines and cow reproduction
Misuse of treatments as detrimental as no action
Dairy producers received a primer on how vaccines can affect reproduction in cows during the Monett Dairy Day conference held Tuesday at the Monett National Guard Armory.
Dr. Scott Poock, veterinary medicine specialist for the University of Missouri in Columbia reported the biggest mistakes farmers make with vaccines come in handling them, either not keeping them cool enough or allowing too much contact with sunlight, damaging the contents. Not following directions provides other issues, especially in handling modified live virus vaccines, which work faster and last longer, and vaccines formed from killed viruses, which work slower and require a booster.
Failure can also come from incorrect timing, the presence of high antibodies, giving vaccines when the cow is too young and genetic influences.
Poock concentrated on the three conditions the most frequently cause reproduction problems. Bovine viral diarrhea can infect calves in utero, and persistently infected cattle become a liability to keep. The virus, if introduced to a fetus early will kill it. If introduced between the 70th and 120th day, the calf will not recognize the virus as an infection and will not fight it. Thus the virus becomes a “Trojan horse” that can create problems over the life of the calf.
Infectious bovine rhinotracheitis and leptospirosis can be controlled with vaccination, though rhinotracheitis vaccines will not prevent a latent infection, Poock said.
Poock suggested a generic vaccination scheme and warned against some of the most persistent problems. Borrowing or leasing bulls opens up a wide range of security risks, especially from venereal disease. He urged sustaining good communication with neighbors, maintaining accurate records, purchasing virgin heifers, maintaining a young bull battery and utilizing artificial insemination.
The “disease” that most commonly causes poor reproduction on dairy farms Poock identified as “asemenosis” or not breeding the cow. The top Missouri herd has double the conception rate of the Missouri average, which falls below the national average. The University of Missouri’s own herd surpasses the national average, supporting the strategies advocated.