Dairy Cattle Reproduction (Part 2)

Question 1

Fertile life of ova

Answer 1

6 - 10 hours

Question 2

First ovulation after calving (days): usually silent ovultation

Answer 2

15 - 20 days

Question 3

Entry of embryo into uterus

Answer 3

72 - 96 hours

Question 4

Heifers should be bred when they are large enough to avoid …

Answer 4

dystocia (difficult calving)

Question 5

For Holstein heifers, the target breeding weight …

Answer 5

(360 - 400 kg) should be reached by 15 m of age, so
that AFC = 24 m

ADG of 0.75 kg is sufficient

Question 6

Too rapid growth before puberty

Answer 6

Negatively affects the development of the mammary gland and, consequently future milk yield

Also there is a risk of dystocia

Question 7

Age at first calving (AFC)

Answer 7

24 months

Question 8

If the age at first calving was 30 months . that indicates

Answer 8

The cow wasn’t insemintaed at 15 months age

Question 9

First estrous after calving

Answer 9

42 day

First 21 day → silent ovulation
Second 21 day → Observed estrous

Question 10

Do the first estrous after calving is breedable ?

Answer 10

No , because the cow still in VWP

Question 11

If the first estrous after calving was delayed after 42 day . that indicates

Answer 11

The cow has an estrous problem

Question 12

First service after calivng

Answer 12

65 day

Question 13

Calving to conception interval (CCI)

Answer 13

85 - 100 day

Question 14

Days open meaning and duration

Answer 14

The period which the cow is not pregnant in

120 day

Question 15

Days open include …..
Calving to conception interval include …

Answer 15

Pregnant , non pregnant
Pregnant

Question 16

Interval measure

Answer 16

AFC
CCI
DO
1st observed estrous
1st service
CI

Question 17

Heat detection rate …

Answer 17

80%

Question 18

Conception rate …

Answer 18

60%

Question 19

Services per conception …

Answer 19

1.7

1/Conception rate

Question 20

Pregnancy rate …

Answer 20

not < 35%

Question 21

Born

Answer 21

Heifer calves retained for herd

Question 22

Weaned

Answer 22

6 – 12 weeks (1.5 – 3 months)

Question 23

Breeding (Pregnant)

Answer 23

15 months (age)

Question 24

Calving

Answer 24

First calf 24 month (15 months age + 9 months Pregnancy period)

Question 25

Breeding (Pregnant) post calving

Answer 25

85 – 100 d post calving

Question 26

Continue Lactating

Answer 26

10 months

Question 27

Drying

Answer 27

50 - 60 d before calving

Question 28

Calving

Answer 28

280 d after breeding (9 months + 10 days)

Question 29

First 60 days

Answer 29

Not pregnant (Open) and Lactating

Question 30

After 110 days

Answer 30

Pregnant and Lactating

Question 31

60 Days before calving

Answer 31

Pregnant and not Lactating

Question 32

At 0 month age

Answer 32

Calf born

Question 33

At 15 month age

Answer 33

First Insemination And becomes pregnant

Question 34

At 24 month age

Answer 34

First Calving + starts milking

Question 35

At 27 month age

Answer 35

Second insemination for the second pregnancy

Question 36

At 34 month age

Answer 36

Drying off

Question 37

At 36 month age

Answer 37

Second calving + begins milking