Lecture 15: Beef management, BRD

Dieases of importance in cows

Repro, lameness, nutritional/metabolic, ocular (pink eye, cancer)

Time period for low cost growth

Stocker

What are the most common issues in stocker operations?

BRD, bloat, pinkeye, lameness

Goal of feedlot

Optimize weight gain to produce beef

Diseases of interest for feedlots

BRD, AIP, acidosis, bloat, found, lameness, digital dermatitis, toe-tip necrosis

Management system for cow-calf operations

Hand-written, computer, handheld devices/bloudcased

Feedlot management records

Hand-written, computer/cloud based

Benefit of digital records

Allows for easier monitoring of treatment records and placement of protocols

When does BRD occur in feedlot?

Cattle on <45 days of feed

What is BRD called in calves?

”summer pneumonia”

CS of BRD

• Depressed

• Lethargic

• Dyspnea

• Purulent/secretory nasal discharge

• Droopy ears

• Anorexia

• Febrile

• >104.0 F

BRD is the cause of ___% of all feedlot morbidity

75%

How does BRD affect ADG, live weight, and quality

Negatively effects all three

What is risk of BRD dependent on?

Arrival weight, stress, previous nutritional status, previous vaccine/immune status

Mortality rate for ultra high risk cattle

>5%

Mortality rate of high risk cattle

~2-5%

Mortality rate for medium risk cattle

~1-2%

Mortality rate for low risk cattle

<1%

Gram negative rod bacteria

Completely hemolytic (blood agar and MacConkey to growth)

Virulence factors include: Capsular polysacchride, fibriae, leukotoxin, LPS

Several serovars: A1-A12 (A1 and A2 most common)

Mannheimia haemolytica

Necropsy findings with M. haemolytica

Fibrinosuppurative and necrotizing inflammatory pneumonia

• Gram negative coccobacillus bacteria

• Widely distributed in nature

• Typically culture with M. haeumolytica

• LPS in outer membranes

• Associated w/ bacterial pneumonia

Paasteurella multocida

When does shipping fever occur?

3-10 days after cattle is heavily stressed. Highly associated with fibrinoous pneumonia ± suppurative

• Gram negative pleomorphic cocci

• Hemolytic on blood agar

• growth is more complicated

• Commensalism organism on MM

• Associated w/ later days on feed BRD (21-35 days)

• Causes sepictemia and n thrombus

• Causes arthritis, pericarditis, myocarditis

Histophilus somi

What is mycoplasma bovis known to cause?

BRD, otitis media, arthritis, mastitis, typically associated with chronic pnuemonias

Necropsy findings with mycoplasma bovis

Microabscesses in the lungs

Family herpesvirdae, respiratory disease. can cause viremia and abortions. CS include: fever, rhinitis, conjuctivitis, inappetence, and labored breathing

BHV-1

Pneumovirus, cattle, goats and sheep affected. Targets cattle 3-12 months of age. Infects epithelial cells from the nasal mucosa, including the type II pneumocytes and alveolar marcorphages

Bovine respiratory synctical virus

Paramyxovirus, that is limited to respiratory tract. Compromises nasal respiratory tract allowing for microbial growth.

Bovine parainfluenza virus

Flavivirdae family (BVD1 and BVD2) with many different manifestations

BVD

When does persistent infection occur in BVD?

~40-130 d

How should you handle BVD testing?

• Pool ear notch testing

• Individually test positive pools

• Positive animals should be terminated

• Test dam of positive calves and remove from herd

Winter dysentery (adult cattle). can cause BRD symptoms in calves

Bovine coronavirus

DNA adenoviruscan cause respiratory and digestive disorders

Adenovirus

Considering the impact of Bovine Viral Diarrhea Virus (BVDv) on feedlot cattle, which diagnostic approach is most effective for identifying persistently infected (PI) animals upon arrival?

a) Observing clinical signs

b) Waiting for clinical signs to appear

c) Performing IHC (formalin-fixed tissue) or PCR (fresh tissue) on ear notch samples

d) Monitoring feed intake

c) Performing IHC (formalin-fixed tissue) or PCR (fresh tissue) on ear notch samples

Which clinical sign is most indicative of Bovine Respiratory Disease (BRD) in a feedlot setting?

a) Increased appetite

b) Clear nasal discharge

c) Dyspnea (difficulty breathing) and purulent nasal discharge

d) Normal temperature

c) Dyspnea (difficulty breathing) and purulent nasal discharge

What is a major reason for the shrinking beef cattle inventory in the USA?

a) Increased consumption of beef

b) Drought, urban sprawl, and crop production

c) Decreased demand for beef

d) Increased export of beef

b) Drought, urban sprawl, and crop production

What are the diseases of importance for beef calves?

a) Reproductive issues

b) Musculoskeletal issues

c) Neonatal diarrhea and respiratory disease

d) Nutritional/metabolic issues

c) Neonatal diarrhea and respiratory disease

What is the primary disease concern in stocker/backgrounder cattle?

a) BRD (Bovine Respiratory Disease)

b) Bloat

c) Pinkeye

d) Musculoskeletal issues

a) BRD (Bovine Respiratory Disease)

What is the most economical disease in the feedlot industry?

a) Bovine Respiratory Disease

b) AIP – Acute Interstitial Pneumonia

c) Metabolic disease

d) Musculoskeletal issues

a) Bovine Respiratory Disease

In a recent outbreak of Bovine Respiratory Disease (BRD) on a feedlot, diagnostic testing reveals a high prevalence of Histophilus somni. Which aspect of the feedlot's management practices would be most relevant to investigate, given the typical disease course associated with this pathogen? a) Vaccination protocols upon arrival of cattle b) Housing and ventilation conditions to mitigate acute viral infections c) Days on feed (assessing cattle typically on feed for 21-35 days) and metaphylactic antibiotic use d) Trace mineral supplementation

c) Days on feed (assessing cattle typically on feed for 21-35 days) and metaphylactic antibiotic use

Which of the following is an industry-important topic in beef production?

a) Increasing herd sizes

b) Ignoring animal welfare

c) Sustainability, welfare, and antimicrobial stewardship

d) Maximizing waste pollution

c) Sustainability, welfare, and antimicrobial stewardship

In feedlots, BRD is most prevalent in cattle within how many days of being on feed?

a) < 45 days

b) 45-90 days

c) 90-120 days

d) >120 days

a) < 45 days

What are the clinical signs of BRD?

a) Euphoria

b) Increased appetite

c) Depression, lethargy, dyspnea, nasal discharge

d) Clear eyes

c) Depression, lethargy, dyspnea, nasal discharge

What percentage of feedlot morbidity is attributed to BRD?

a) 25%

b) 50%

c) ~75%

d) 90%

c) ~75%

.

How does BRD impact average daily gain (ADG)?

a) Decreases ADG

b) Increases ADG

c) No impact on ADG

d) Unpredictable impact on ADG

a) Decreases ADG

What factors increase the risk of BRD?

a) High arrival weight and low stress

b) Known vaccine history and weaning

c) Stress, unknown vaccine status, and long transport

d) Previous good nutritional status

c) Stress, unknown vaccine status, and long transport

What is an example of an "ultrahigh" risk factor for BRD?

a) Heifers

b) Known source

c) "Fly weight" cattle with unknown vaccine history, intact males, mixed sources, long transport times

d) Cattle >750lbs

c) "Fly weight" cattle with unknown vaccine history, intact males, mixed sources, long transport times

Which of the following is a bacterial agent associated with BRD?

a) Bovine Herpes Virus-1 (BHV-1)

b) Bovine Respiratory Syncytial Virus (BRSV)

c) Mannheimia haemolytica

d) Bovine Viral Diarrhea Virus (BVDv)

c) Mannheimia haemolytica

Which virulence factor is associated with Mannheimia haemolytica?

a) Ribosomes

b) Leukotoxin (Lkt)

c) Mitochondria

d) Flagella

b) Leukotoxin (Lkt)

What pathological lesion is Mannheimia haemolytica commonly associated with?

a) Fibrinosuppurative and necrotizing inflammatory pneumonia

b) Micro abscesses in lungs

c) Winter dysentery

d) Arthritis

a) Fibrinosuppurative and necrotizing inflammatory pneumonia

What type of pneumonia is shipping fever highly associated with?

a) Fibrinous Pneumonia +/- suppurative

b) Chronic pneumonia

c) Interstitial pneumonia

d) Granulomatous pneumonia

a) Fibrinous Pneumonia +/- suppurative

Mycoplasma bovis is associated with which condition in cattle?

a) Red-Nose

b) Otitis media

c) Winter dysentery

d) Shipping fever

b) Otitis media

How is BVDv problematic in feedlot cattle?

a) Persistently infected animals shed virus constantly

b) Causes winter dysentery

c) Causes Hairy heel warts- Digital dermatitis, toe-tip necrosis

d) Causes Red-Nose

a) Persistently infected animals shed virus constantly