My first thought is that it takes at least 2 weeks after receiving immunization for calves to build up antibodies so they have any immunity at all. And, if the vaccine is one that requires a second shot, the animals won't have any immunity until 2 weeks after the second shot, not the first shot. The first shot merely "primes the pump" but doesn't confer any actual immunity.
I commend you for your efforts to keep disease out of your animals and your property. That sounds like a monumental task if new calves are continually being brought onto the property. Do you have a way of quarantining new animals for at least a month? Are you using clean needles to draw up vaccines and medications? Are you using a clean needle to vaccinate each calf? Are your vaccines stored under refrigeration and out of sunlight?
When animals are vaccinated during a time when their bodies are stressed, their immune systems just don't respond as well as they would if the animal wasn't stressed.
And, you don't know if the calves are getting sick due to a virus, or a bacteria or a fungus, or what. It kind of sounds like you might be battling a virus, since the antibiotics aren't helping. Antibiotics can't kill a viral infection. They can help if a secondary bacterial infection has taken hold in a weakened animal. Again, it has to be an antibiotic the bacteria is susceptible to.
Have you had a good vet examine the calves? I'm out of ideas for tonight. I hope you can come up with a solution. It's hard to care for so many sick animals for so long.
> I have a group of 29 small beef
> calves put together from sale
> barns.All vaccinated for ibr bvd
> pi3 brsv when brought in and was
> follow up vaccinated 3-4 weeks
> later.14 out of 29 got very sick.
> Coughing droopy ears runny noses
> decreased appetite.LA200 and
> sulfer pills worked fairly well
> but I have 7 still seperated out
> that didn't respond so I gave
> nuflor and they still haven't come
> around the way I would like.Got
> tired of sticking them and they
> haven't had anything in over two
> weeks other than aeromyacin in
> feed.I am thinking about micotil
> but this is getting very
> expensive.This is an ongoing
> problem for me even though I feel
> I have a good vaccination plan
> from the time I get the calves in
> I always seem to get sick calves
> and end up spending alot of money
> on nuflor micotil and other
> antibiotics even after I have
> given all the prevention
> vaccinations.I have wondered if my
> farm is infected.I am located
> close to a town and have wondered
> if the noise sirens trucks ect
> might induce stress on the animals
> and cause sickness.Any suggestions
> anyone may have are greatly
> appreciated.Let me add that
> holstein cattle do well here and
> do not get sick but I can't afford
> to feed holsteins.