ICAR AICE-JRF/SRF Dairy Animal Science: practice questions

1 · Dairy breeds of cattle and buffalo worldwide · medium

How many chromosomes do river buffalo have, compared with swamp buffalo?

1. 50, against 48 in swamp buffalo
2. 48, against 50 in swamp buffalo
3. 60, the same as in cattle
4. 46, against 44 in swamp buffalo

2 · Dairy breeds of cattle and buffalo worldwide · hard

Why do high-grade Holsteins often perform poorly in low-input tropical smallholdings?

1. Holstein milk is illegal to sell in tropical countries
2. Holsteins cannot digest any tropical forage species at all
3. Holsteins produce no milk at all once the air temperature rises above 25 °C in summer
4. Their high requirements exceed available feed, health care and heat tolerance

3 · Anatomy of the mammary gland · hard

Where is most of the milk in a cow's udder stored just before milking?

1. In the gland cistern only
2. In the milk veins
3. In the alveoli and small ducts
4. In the teat cistern

4 · Lactation physiology and milk synthesis · medium

Which hormonal change at parturition triggers copious milk secretion (lactogenesis)?

1. Rising progesterone with falling prolactin and falling cortisol
2. No hormonal change; lactogenesis is purely mechanical
3. Rising oestrogen with falling oxytocin and insulin
4. Falling progesterone with rising prolactin and glucocorticoids

5 · Feeding for milk yield and composition · hard

Which biohydrogenation intermediate is linked to diet-induced milk fat depression?

1. Butyric acid
2. trans-10, cis-12 conjugated linoleic acid
3. Stearic acid
4. cis-9, trans-11 conjugated linoleic acid

6 · Mastitis and somatic cell count · medium

Which change in milk composition is typical of mastitis?

1. Higher lactose and casein, lower sodium and chloride
2. Higher fat and no change in minerals
3. Lower pH and lower serum albumin
4. Lower lactose and casein, higher sodium and chloride

7 · Mastitis and somatic cell count · hard

Cows give 10 kg at 100,000 cells/mL, 20 kg at 400,000 and 10 kg at 1,000,000. What is the bulk milk SCC?

1. 475,000 cells/mL
2. 500,000 cells/mL
3. 1,500,000 cells/mL
4. 400,000 cells/mL

8 · Herd records, lactation curves and economic traits · medium

Which κ-casein variant is associated with better rennet coagulation and cheese yield?

1. κ-casein A
2. κ-casein B
3. κ-casein E
4. β-casein A1

9 · Herd records, lactation curves and economic traits · hard

How has genomic selection changed dairy cattle breeding since about 2009?

1. Young animals are evaluated from DNA, shortening generation intervals
2. Progeny testing of every bull now takes twice as long
3. Artificial insemination has been banned in favour of natural mating
4. Milk recording is no longer needed for any purpose

10 · Housing, welfare and heat stress in dairy animals · hard

How does clean housing relate to milk quality for processors?

1. It removes the need for milk cooling
2. It cuts environmental mastitis, bacteria and spores in milk
3. It has no relation to milk quality
4. It raises the lactose content of the milk by two per cent or more