Dairy 2

Question 1

What are three ways you can diagnose pregnancy in a cow?

Answer 1

• Palpation
• Laboratory tests for hormones
• Ultrasound

Question 2

Which hormone should you test to diagnose pregnancy in a cow?

Answer 2

Progesterone (two samples will give you the best results)

Question 3

At which day into pregnancy can you palpate to confirm pregnancy in a cow?

Answer 3

35-40 days post-breeding

Question 4

What is the primary sign of pregnancy in a cow upon palpation?

Answer 4

The embryonic vesicle or fetus (depending which day of gestation it is)

Question 5

At which day into pregnancy can you palpate an embryonic vesicle?

Answer 5

35-65 days

Question 6

At which day into pregnancy can you palpate a fetus?

Answer 6

Day 55+

Question 7

What are the secondary signs of pregnancy in a cow upon palpation?

Answer 7

• > 100 day fetus in cavity
• Membrane slip (≥ 30-90 days)
• Placentomes ( 90+ days)
• Uterine artery fremitus (105+ days)

Question 8

Which four things are assessed when ultrasounding a pregnant cow?

Answer 8

1. Confirm true pregnancy versus presence of ovarian cyst
2. Fetal age and size
3. Fetal viability (heartbeat and movement)
4. Fetal sexing

Question 9

At what day into pregnancy can you determine fetal sex?

Answer 9

Day 55+

Question 10

How can you tell the sex of a fetus on an ultrasound?

Answer 10

Look for the genital tubercle (scrotum in male and vulva in female)

Question 11

Which type of cows are more prone to twinning, dairy or beef?

Answer 11

Dairy (2.5-5.8% incidence vs beef is < 1%)

Question 12

What are three risks of twinning in cows (risks to the fetus)?

Answer 12

• Increases risk of embryo and fetal loss (abortion, stillbirths, dystocia, neonatal calf mortality)
• Risk of lower body weight at birth
• Risk of freemartinism

Question 13

Which normal physiological event occurs at at < 7 days of gestation in the cow? What percentage of embryo loss do we expect at this stage?

Answer 13

Embryo genome activation and early development stage (< blastocyst):

There is a 10-50% incidence of embryo loss

Question 14

What are the most common causes of embryo mortality at this stage? (<7 days after fertilization)

Answer 14

• Inadequate progesterone levels before AI
• Low quality oocytes
• Embryo-maternal mismatch (uterine secretions)
• Metabolic disease in cow post-calving
• Heat stress

Question 15

Which normal physiological event occurs at days 8-30 of gestation in the cow? What are the most common causes of embryo mortality at this stage? What percentage of embryo loss do we expect at this stage?

Answer 15

Maternal recognition and implantation stage:

• Inadequate progesterone levels post AI
• Inadequate embryo elongation
• Embryo-oviduct/uterus mismatch (secretions)

There is a 20% incidence of embryo loss at this stage.

Question 16

Which normal physiological event occurs at days 30-60 of gestation in the cow? What are the most common causes of embryo mortality at this stage? What percentage of embryo loss do we expect at this stage?

Answer 16

Placental development & fetal organogenesis stage:

• Inadequate placentome formation (placenta)
• Inadequate placental vascular development

There is a 5-20% incidence of embryo loss at this stage

Question 17

Which normal physiological event occurs at days 60-90 of gestation in the cow? What are the most common causes of embryo mortality at this stage? What percentage of embryo loss do we expect at this stage?

Answer 17

Placental and fetal growth stage:

• Twinning

There is a 2-4% incidence of embryo loss at this stage

Question 18

Which physiological stage of pregnancy in the cow has the highest risk of embryo loss?

Answer 18

Embryo genome activation and early development stage (10-50% loss)

Question 19

Which physiological stage of pregnancy in the low has the lowest risk of embryo loss?

Answer 19

Placental and fetal growth stage: (2-4% loss)

Question 20

What are the five reproductive parameters?

Answer 20

1. Conception risk/rate
2. Pregnancy risk/rate
3. Heat detection rate
4. Average days open
5. Calving interval

Question 21

What is the average days open interval?

Answer 21

The interval between calving and conception (days not pregnant)

Question 22

Which reproductive parameter is most commonly used?

Answer 22

Calving interval

Question 23

What is the calving interval?

Answer 23

Time interval from calving to next calving (should be around a year)

Question 24

What is conception rate?

Answer 24

Conception risk is the # cows pregnant/# cows bred (only cows AI’ed)
How many cows got pregnant out of all the ones you bred via AI

Question 25

How can you determine conception rate from a table?

Answer 25

Conception risk (rate) = pregnant/bred

Question 26

What is considered a "good" conception rate?

Answer 26

>40%

Question 27

What is pregnancy rate?

Answer 27

Pregnancy risk is the # cows pregnant/# cows eligible to be bred *How many cows got pregnant out of all the ones that could have been bred*

Question 28

How can you determine pregnancy rate from a table?

Answer 28

Pregnancy risk (rate) = pregnant cows/eligible bred

Question 29

What is considered a "good" pregnancy rate?

Answer 29

>20%

Question 30

What is a heat detection rate?

Answer 30

Heat detection rate = #cows bred / # eligible cows (in a 21 day period) *How many cows were bred out of all the ones that could have been bred*

Question 31

How can you determine heat detection rate from a table?

Answer 31

Heat detection rate = bred/eligible bred (in a 21d-period)

Question 32

What is considered a "good" heat detection rate?

Answer 32

>60%

Question 33

How can you determine abortion rate from a table?

Answer 33

Percentage abortions = abortions/pregnant

Question 34

What is considered an acceptable abortion rate?

Answer 34

5-8% in a 21 day period