NAVLE Bovine Herd Health Questions and Answers

Question 1

A dairy manager is concerned about a rising bulk tank somatic cell count (SCC).
Which of the following is the most effective and direct on-farm screening tool to identify individual cows with subclinical mastitis?

Accepted Answer

California Mastitis Test (CMT)

Answer

Bulk tank culture

Answer

Teat end scoring

Answer

Direct microscopic somatic cell count (DMSCC)

Question 2

A producer is implementing a control program for Bovine Viral Diarrhea Virus (BVDV). What is the most critical step to eliminate the primary reservoir of the virus within the herd?

Accepted Answer

Identifying and removing all persistently infected (PI) animals.

Answer

Vaccinating all adult cows annually with a modified-live virus (MLV) vaccine.

Answer

Implementing strict fly control measures during summer months.

Answer

Culling all animals that test positive on a BVDV antibody ELISA.

Question 3

A high-producing dairy cow, 3 days post-calving, presents with a head turned into her flank, muscle fasciculations, a dry muzzle, and a heart rate of 100 bpm with weak pulse quality. She is afebrile and unable to stand. What is the most likely diagnosis?

Accepted Answer

Hypocalcemia (Milk Fever)

Answer

Ketosis

Answer

Displaced abomasum

Answer

Metritis

Question 4

A 4-year-old beef cow presents with a history of chronic, profuse, watery diarrhea and significant weight loss over several months despite maintaining a normal appetite. On rectal palpation, the rectal mucosa feels thickened and corrugated. What is the most likely causative agent?

Accepted Answer

Mycobacterium avium subsp. paratuberculosis

Answer

Salmonella enterica serovar Typhimurium

Answer

Eimeria spp.

Answer

Bovine Viral Diarrhea Virus (BVDV)

Question 5

Which of the following is the most critical component of a biosecurity program to prevent the introduction of infectious diseases into a closed beef cow-calf herd?

Accepted Answer

Testing and quarantining all newly purchased animals.

Answer

Requiring all visitors to wear disposable plastic boots.

Answer

Vaccinating the resident herd for all common regional diseases.

Answer

Maintaining a double-fenced perimeter to prevent nose-to-nose contact.

Question 6

A beef herd experiences an 'abortion storm' in the last trimester of gestation. Histopathology of several aborted fetal brains reveals multifocal, nonsuppurative necrotizing encephalitis with associated protozoal cysts. What is the most likely etiologic agent?

Accepted Answer

Neospora caninum

Answer

Bovine Herpesvirus 1 (IBR)

Answer

Leptospira interrogans

Answer

Brucella abortus

A dairy manager is concerned about a rising bulk tank somatic cell count (SCC).Which of the following is the most effective and direct on-farm screening tool to identify individual cows with subclinical mastitis?

A dairy manager is concerned about a rising bulk tank somatic cell count (SCC).
Which of the following is the most effective and direct on-farm screening tool to identify individual cows with subclinical mastitis?