National Veterinary Examination Food-Animal Production Medicine & Herd Health: practice questions

1 · Herd health programmes · medium

Which blood test and timing are most appropriate for herd monitoring of subclinical ketosis in dairy cows?

1. Non-esterified fatty acids in cows at mid-lactation, around 150 days in milk, with 1.2 mmol/L as the ketosis cut point
2. Beta-hydroxybutyrate in cows in the first two weeks after calving, with 1.2 mmol/L as a common cut point
3. Beta-hydroxybutyrate in heifers at first service, because ketosis is mainly a disease of heifers
4. Serum calcium in dry cows eight weeks before calving, with 2.5 mmol/L as the ketosis threshold

2 · Fertility management · easy

To achieve a 365-day calving interval with a 282-day gestation, by about how many days after calving must a cow conceive?

1. 83 days
2. 78 days
3. 282 days
4. 60 days

3 · Fertility management · medium

On the five-point body condition scale, which change in early lactation is associated with poorer herd fertility?

1. Holding body condition at about 3.0 from calving through to first service
2. Gaining half a condition score unit during the dry period in thin cows
3. Losing a quarter of a condition score unit in the last month of lactation
4. Losing more than about one condition score unit between calving and first service

4 · Mastitis control · easy

Which group lists only contagious mastitis pathogens?

1. Streptococcus uberis, Streptococcus agalactiae and Pseudomonas from soil
2. Escherichia coli, Klebsiella species and Streptococcus uberis from bedding
3. Staphylococcus aureus, Streptococcus agalactiae and Mycoplasma species
4. Staphylococcus aureus, Escherichia coli and Klebsiella species from water

5 · Mastitis control · hard

A herd has a bulk SCC of 480,000 cells/mL, few clinical cases, and many cows with SCC above 200,000 at two successive recordings. Cultures grow Staphylococcus aureus. Which control measure is most specific to this problem?

1. Changing from straw to sand bedding to reduce coliform exposure between milkings
2. Pre-milking teat dip only, since pre-dipping is the main control for contagious mastitis
3. Treating every high-SCC cow in lactation for eight weeks, as Staph. aureus cures readily in lactation
4. Milking infected cows last or with a separate unit, and culling chronically infected cows

6 · Calf health · medium

Housed dairy calves aged 3–8 weeks have recurrent pneumonia. The shed is humid, smells of ammonia and has no air inlets at eave level. What is the primary intervention?

1. Give all calves a long-acting antimicrobial injection monthly until they are weaned
2. Improve ventilation through inlets and outlets without creating draughts at calf level
3. Close the remaining gaps to keep the calves warm and stop any air movement
4. Increase stocking density so the calves generate more body heat in winter

7 · Biosecurity · medium

What is the recommended management of newly purchased cattle arriving on a farm?

1. Housing them in the calf shed, since calves have the strongest immunity on the farm
2. Isolation for three to four weeks, without shared air space or drainage, while tests are completed
3. Releasing them to shared pasture after a single dose of broad-spectrum antimicrobial
4. Mixing them with the milking herd on the day of arrival so that they adapt to the herd's microbial flora

8 · Performance records and KPIs: calving interval, SCC, ADG and FCR · easy

Which of these is a leading indicator of dairy herd fertility?

1. Lifetime milk yield
2. 21-day pregnancy rate
3. Age at culling
4. Calving interval

9 · Small-ruminant flock health · medium

Which organism is the essential transmissible agent of ovine footrot?

1. Fusobacterium necrophorum alone
2. Treponema pallidum
3. Dichelobacter nodosus
4. Erysipelothrix rhusiopathiae

10 · Pig and poultry flock medicine · easy

Which pig herd KPI is calculated as sows farrowing divided by sows served?

1. Litters per sow per year
2. Pre-weaning mortality
3. Farrowing rate
4. Non-productive days