Friday Test

Question 1

1. Outline three reasons why Holsteins are the largest breed in Australia.

Answer 1

1. Milk quality
2. Milk production
3. Withstanding harsher environments

Question 2

2. Name one other dairy breed. Explain why a farmer may utilise this breed in their herd.

Answer 2

Jerseys, because their milk is creamier than a Holsteins, its better to make butter with.

Question 3

3. Outline five traits that are desirable in a dairy cow, and explain how they impact productivity in dairy cattle.

Answer 3

Milk quality
Milk production
Behaviour
Udder structure
Size

Question 4

1. Define Somatic Cell Counts.

Answer 4

The quality of the milk, the lower the better at a maximum of 400,000.

Question 5

2. Explain three treatments for Mastitis in a dairy cow.

Answer 5

anti-inflammatories, mastitis tube and systemic antibiotics.

Question 6

3. Explain the difference between sub-clinical and clinical mastitis.

Answer 6

clinical is the inflammation in the udder (visible) and sub-clinical is where it doesn’t show to the naked eye, but it’s still there.

Question 7

4. Explain three ways a dairy farmer can identify if a cow has mastitis.

Answer 7

1. Worsened milk quality
2. Udder swelling
3. Less milk output

Question 8

5. Outline how the dairy/farm environment can impact mastitis rates on dairy farm.

Answer 8

Dirty environments can have increased bacteria, making it more likely for the cows to catch mastitis.

Question 9

6. Outline the impact of sub-clinical mastitis on profits and cow health on a dairy farm.

Answer 9

as to there being less quantity and quality of milk due to the udders swelling up, their profit lessens, and if it spreads that’ll take it down even more.

Question 10

1. Define drying off in regard to dairy production.

Answer 10

they stop getting milked just before the dry period, and only get fed until they calf again.

Question 11

2. Explain why a dairy farmer needs to ensure adequate nutrition for a dairy cow to optimise milk production throughout their lactation.

Answer 11

if the proper nutrition for the cow isn’t met, then the milk quality will decrease and they will have a more likely chance of getting an infection.

Question 12

3. Outline why it is not sustainable for a dairy cow to be milked past approximately 300 days of lactation.

Answer 12

their milk production is at its lowest, and it frustrates the cow.

Question 13

1. Dairy cattle genetics have utilised selective breeding for milk volume. Explain how milk production has increased over time, and why dairy farmers have concentrated on improving this trait.

Answer 13

due to dairy farmers going for genes with more quality milk and quantity, it makes sure that there’s high quality output, plus there being a lot extra.

Question 14

2. Define the term replacement heifers.

Answer 14

externally sourced cows that are for long-term use, replacing older cows.

Question 15

3. Explain how a farmer can select desirable traits in their replacement heifers to improve a trait(s) in their herd.

Answer 15

they can select a different trait that they cant seem to get much of, improving their balance and income.

Question 16

4. Farmer Smith runs a 200 Holstein Friesian cow dairy on the Fleurieu Peninsula in South Australia. His neighbour Famer Brown runs a 250 Holstein Friesian cow dairy approximately 5 kilometres away. Their herd tests indicate that Farmer Smith is achieving 65 litre per hectare, whereas Farmer Brown is 42 litres per hectare.

a. Outline three key dairy management factors you believe could be causing such a significant difference between the two farms.

b. Explain how Farmer Smith could utilise selective breeding overtime to improve the milk production in his herd.

Answer 16

a. different genetics, nutrients and terrain.

b. getting better genetics to make more quality milk, and more of it, also to up their immunity to disease and illness.

Question 17

5. What is the role of a sire in the improvement of traits in a dairy herd?

Answer 17

to pass on genetics, and if desirable traits come from that sire, they can make cows with better genetics when paired to the right cow.

Question 18

1. Explain why the younger cows have a lower milk production.

Answer 18

they haven’t fully developed yet, therefore their output is still developing due to genetics passed down taking time to be prominent.

Question 19

3. Provide three reasons this farmer has a higher milk production (litres) than the district average.

Answer 19

better genetics - better feed - nutritional levels always up