BRDC and sick calves Flashcards
what are our bacterial agents of BRDC
manheimia hemolytica, pasteurella multocida, histophilus somnus, mycoplasma bovis
most economically important disease in feeder cattle
BRDC- not only deaths but decreased gains, decreased carcass value.
three major factors of BRDC
weather, nutrition, stressors
when does the clinical signs of BRDC surface
7-21d post shipping/stress
how does the bacteria infect
virus destroys the cells in the lungs, bacteria migrate to the lungs and set up shop, leukotoxin causes inflammation, destroys lung tissue, lung tissue calls more WBC, which get killed by leukotoxin, spiral
what is our death loss goal for stocker production
less than 4% loss
which factors are most important in preventing brdc
what calves you purchase, nutrition, other stressors (presconditioning, bulls vs steers).
what is preconditioning
vaccination before shipping (14-21d prior to stressor), weaned,
bunk broke
what is the gold standard amount of time to wean
45days pre stressor
what are the preconditioned vaccines
IBR-BVD (at least one MLV)
mannheimia
blackleg- 7way
14-21 days prior
why is MLV preferred for the IBR-BVD vax
MLV stimulates more than one part of the immune system
what are the best calves to sell
weaned calves, vaccinated and from one farm, calves comingled prior to sale
farm receives gold star calves, what do we want the producers to do now
parasite control +- implants
what calves would benefit from metaphylaxis
stale, sale barn calves. cheap, been from multiple markets
when does BVD PI calves become PI
infection 40-125 days
what increases your likelihood of buying a BVD PI calf?
the more calves you buy, it increases the likelihood
how do we test for BVD PI calves
ear notch. elisa
what does a positive BVD test mean
you have a PI calf
you have a transient infection
you have a false positive test
four inidications for metaphalaxis
on arrival if you expect >33% of calves to get sick
if you already treated >15% in one day
treated greater than >25-30% of calves on three consecutive days
bottom line for steers vs bulls
bull calves get sick more than steers
bull calves gain les than steer calves
why does treatment fail
superbug
antibiotic resistance
problem with timely recognition
when do you use metaphalyxis
if you expect 35% of calves are expected to get sick
very high dollar calves
you suspect mycoplasma, what can you not treat with
ceftiofur, blactams, ppg
why is mycoplasma so bad
deciminated microabscesses through the lungs
