Dairy Cow Quiz 10/21

Question 1

Genetic change via selection

Answer 1

Predict milk production of sire’s offspring
Use of artificial insemination

Question 2

Predict daughter’s performance performance off sires genetics

Answer 2

Sire summary

Question 3

Ex. Milk 1805. What does that mean?

Answer 3

Daughter is expected to produce 1805 more lbs of milk per 305 day lactation cycle compared to breed average

Question 4

Proportion of trait passed from parent to offspring

Answer 4

Heterability

Question 5

What 2 things are used to predict the effect of a sire on a dairy herd.

Answer 5

Average production of breed
Average production of the given herd

Question 6

Which sperm is larger, heavier, and slower?

Answer 6

X

Question 7

Which sperm is lighter, smaller, and faster?

Answer 7

Y

Question 8

bST stands for?

Answer 8

Bovine somatotropin

Question 9

What is another name for bST

Answer 9

Growth hormome

Question 10

What does somatotropin do?

Answer 10

Stimulates somatic cells (body cells)

Question 11

Does bST naturally occur in all species?

Answer 11

Yes

Question 12

What 3 functions does bST have?

Answer 12

Regulate milk production
Increase metabolic rate
Increase lipolysis (fat breakdown)

Question 13

Why is bST used?

Answer 13

It increases the nutrients available for dairy cow to use in milk production. Increases level of milk production

Question 14

How does bST affect feed intake and milk production?

Answer 14

⬆️ feed intake 6-8%
⬆️ milk production 10-20%

Question 15

What year did the use of bST use stop?

Answer 15

2017
Social pressure

Question 16

3 Successes of dairy industry

Answer 16

Dairy Herd Improvement Association (record system)
Limited traits selected
Technology improvement (Artificial insemination and control environment to ⬆️ production)