NAVLE Bovine Herd Health Management 2

Question 1

A dairy herd is experiencing an elevated somatic cell count (SCC) averaging 400,000 cells/mL. Which organism is most commonly associated with contagious mastitis causing elevated bulk tank SCC?

Accepted Answer

Staphylococcus aureus

Answer

Staphylococcus aureus is the classic contagious mastitis pathogen spread cow-to-cow during milking, and is the leading cause of elevated bulk tank SCC in dairy herds.

Question 2

A beef cow-calf operation has a 15% calf mortality rate in the first 30 days of life. Which intervention has the greatest impact on reducing neonatal calf mortality?

Accepted Answer

Ensuring adequate colostrum intake within 6 hours of birth

Answer

Adequate colostrum intake (at least 10% of body weight within 6 hours) provides passive immunity and is the single most impactful intervention for reducing neonatal calf mortality.

Question 3

Which internal parasite of cattle causes 'bottle jaw' (submandibular edema) due to hypoproteinemia?

Accepted Answer

Haemonchus placei

Answer

Haemonchus placei is a blood-sucking abomasal parasite that causes significant protein loss, leading to hypoproteinemia and the classic sign of submandibular edema (bottle jaw).

Question 4

A producer wants to implement a PRRSV (Porcine Reproductive and Respiratory Syndrome Virus) control program. Wait—this is a bovine herd. Which respiratory virus causes 'shipping fever' complex and is commonly controlled with modified-live virus vaccines in beef cattle?

Accepted Answer

Infectious bovine rhinotracheitis virus (IBRV/BHV-1)

Answer

IBRV (BHV-1) is a primary viral pathogen in the bovine respiratory disease complex, and modified-live IBR vaccines are a cornerstone of BRD prevention programs in beef cattle.

Question 5

In a feedlot, the recommended withdrawal time before slaughter must be observed when using which antibiotic for treatment of bovine respiratory disease?

Accepted Answer

Tulathromycin

Answer

Tulathromycin (Draxxin) has a meat withdrawal time of 18 days in the US, and compliance is required to ensure drug residue-free beef at slaughter.

NAVLE - North American Veterinary Licensing Examination Practice Test

NAVLE - North American Veterinary Licensing Examination Practice Test

NAVLE Bovine Herd Health Management 2