Diseases - BRD
What is bovine parainfluenza 3
Common virus
Damages airway cilia and epithelium
Causes primary disease
immunosuppression
Not very severe unless with bacterial infection
lesions - bronchitis
Histophilus somni
Less common cause in nursing calves
Commensal in upper resp tract
Pathogenic and non-pathogenic strains
Certain strains like certain tissues
Lesions - lung, heart, brain
What is BRD
Resp disease complex of the lower resp tract - resulting in pneumonia
Complex - multifactorial disease
Stress due to weaning, shipping, commingling and castration predisposes animals to disease
greatest cause of morbidity and mortality in north american beef cattle
What animals are high risk vs low risk for disease
Ultra high - young (3-6m), light weight, recently weaned, no vaccine and feed history, auction sourced
high - young (5-7m), weight 450-650, recently weaned, no vaccine and feed history, auction sourced
medium - young (6-9m), weight 600-800, pre weaned, vaccinated, some feed history, castrated, direct market
Low - yearling, weight 800-1100, backgrounded, vaccinated, feed history, castrated, direct market
What are the issues with treating BRD
Controlling and treating BRD is becoming harder
Public concerns
Regulatory concerns
Export concerns
What is bovine respiratory syncytial virus
Very common, widespread virus
Rarely causes primary disease, but can occasionally be severe
immunosuppression
Lesions - interstitial pneumonia
Mycoplasma bovis
Found in resp tract of healthy calves
Common in dairy calves
Cause joint and ear infections
lesions - often cranioventral
When and how much does BRD occur
<42 days on feed
14% or more cattle develop BRD in a feedlot
Stockers/backgrounders = 30-70%
What are the health benefits of preconditioning
Reductions in morbidity
Reductions in treatment cost
Improvements in ADG
Improvements in grading
What are the costs associated with lameness
Treatment costs
Culling and salvage losses
Weight loss and production losses in affected animals
Repro losses if bull is lame
What is bovine coronavirus
Very common
Enteric form -> diarrhea
Respiratory form -> predisposes to bacterial secondary infection
lesions - mild interstitial pneumonia
What groups of calves are at risk of nursing calf pneumonia
Neonatal calf - birth-14 days = clinical signs resemble pneumonia, causes congenital issues
Neonatal calf - 2-10 weeks = pneumonia
Suckling calf - 10 weeks to weaning = pneumonia
Weaned calf
What are the impacts of stress
Decrease feed intake, Rumen function and digestion
Increases glucocorticoid and catecholamine levels
increase in colonization of upper airway with pathogenic strains of mannheimia, other bacterial pathogens
How do you identify BRD
Attitude - alertness, rise and strech
Eating - rumen fill, gut fill
Respiration - Increased resp rate and effort, cough, nasal discharge
What are the four categories of lameness
Foot rot - 74%
Joint infections 16.1%
Lame with no visible swelling - 6.1%
injuries - 3.1%
Mannheimia haemolytica
different serotypes - serotype 2 -> commensal in cattle, serotype 1 & 6
Produces endotoxins and leukotoxins
Lesions - cranioventral
what are the risk factors for nursing calf BRD
Failure of passive transfer
Large herd size
Diarrhea in calves
Winter calving season
Intro of calves from outside source
Offering supplemental feed to calves
What is the disease sequence of events
Stress -> immune dysfunction
Suscepetible animal exposed to pathogen
Incubation of viral pathogen - avg 2-7 days
Primary viral BRD - avg 3 days
Secondary bacterial BRD - avg 3-5 days after initial viral infection
What does DART stand for
Depression
Appetite
Respiration
Temperature
What is the 90-90-90 rule
90% of lameness is caused by a lesion in the foot
90% of those lesions in the hind leg
90% of those lesions are in the lateral claw
Pasteurella multocida
Commensal in upper resp tract
Many serogroups and types
produces endotoxin
Common in cattle with BRD
lesions - cranioventral
use management protocol not just vaccine protocol
Dam nutrition, vaccination
management of the environment
Colostrum management
Calf vaccination
How do you manage BRD
Understand the risk level of animals purchased
Proper nutrition and pen management
Vaccination on arrival vs Preconditioning
Metaphylaxis on arrival
Staff training for identification of sick calves
treatment protocols
What is the treatment for BRD
Antimicrobials
Best treatment is prevention
What are the four big reasons behind lameness
Infection
Nutrition and environment
Physical injuries
genetics