Heifer Replacement

Question 1

Goal of a dairy replacement management program is to…

Answer 1

raise heifers at a low environmental and economic cost without compromising future lactation performance

Question 2

Target body weight gain for pre-pubertal heifers

Answer 2

1.6 to 1.8 lbs/day

Question 3

How old is a dairy heifer during her breeding period and how much should she weigh at least?

Answer 3

13 months; 780 lbs

Question 4

What is the target body weight gain 10 months prior to calving?

Answer 4

1.8-2 lbs/day

Question 5

What is the target prepartum weight range?

Answer 5

1350 - 1400 lbs pre-calving (calf + heifer) or 1200 lbs after calving

Question 6

What are the goals of dairy replacement regarding costs? (2)

Answer 6

1. obtain a return on investment (ROI) of 2:1 by the time the heifer is culled
2. heifer must make the dairy a profit of $2,000 to 2,500 before she leaves the herd

Question 7

A higher level of mammary gland secretory tissue is observed with…

Answer 7

low average daily gain (ADG)

Question 8

Raising replacements accounts for _____ of a herd’s production costs

Answer 8

~20%

Question 9

The average Holstein cow remains in the herd for _____ lactations

Answer 9

3.4

Question 10

You have approximately _____ lactations to return a profit on your investment

Answer 10

1.5

Question 11

If the cost to raise the heifer is _______, she will begin to show a net positive ROI near the end of her ______ lactation

Answer 11

$1250; 2nd

Question 12

What 4 steps can be taken to maximize the ROI?

Answer 12

• decrease total input cost per heifer
• get heifers into milking herd sooner
• increase milk production in the 1st and 2nd lactation
• manage environment and feeding program to maximize lean growth from weaning to calving

Question 13

What determines the number of heifers in the herd?

Answer 13

the balance between heifer supply and departure

Question 14

The need for replacements depends on…

Answer 14

cow culling rate
rate of expansion of the dairy herd

Question 15

Heifers leaving depends on… (3)

Answer 15

mortality rate
culling rate (voluntary or involuntary)
age at first calving

Question 16

Heifers available depends on… (5)

Answer 16

1. herd size
2. calving interval
3. sex ratio
4. calf mortality
5. age at 1st calving

Question 17

increasing ______ decreases the number of replacements

Answer 17

calving interval; mortality rate

Question 18

Calf mortality should be kept under what percentage?

Answer 18

10%

Question 19

Ideally, heifers should freshen by what age?

Answer 19

24 months

Question 20

Every month after 24 months will require a ___% increase in the annual replacement rate

Answer 20

4.2 (1/24 = 0.042)