Unit 4 - Pre-calving Management

Question 1

What are the 2 points of focus in pre-calving management?

Answer 1

1) nutrition and health of breeding females
2) AI and natural-service sire selection

Question 2

What are the 5 key tasks in pre-calving management?

Answer 2

-reformation of diets to keep pace with fetal growth
-Vaccination against calf scours, if warranted
- preparation of and movement to calving areas
- Gathering calving supplies
-Selection of herd sites

Question 3

What are the major functions of pre-calving management?

Answer 3

1) support of retained breeding females
2) health maintenance
3) preparation for calving
4) sire selection

Question 4

How much fetal growth takes places during the final 60 days of gestation?

Answer 4

60-80%

Question 5

Compared to a non-pregnant animal of the same weight, how much more nutrient requirement is there for a cow in gestation?

Answer 5

1.75 times greater

Question 6

What can failure to react to diet change needs, in the final 60 days of pregnancy, lead to?

Answer 6

-weak labor
-increased dystocia
- extended post-partum interval
-impaired milk production
-reduced weaning weight

Question 7

Define “Scours”

Answer 7

Is a term for calfhood diarrhea that occurs chiefly between 3 and 16 days of age.
HIGHLY CONTAGIOUS

Question 8

What causes scours and what are the symptoms?

Answer 8

Cause: bacteria, viruses, protozoal parasites

Symptoms: rapid dehydration, death, and impaired performance

Question 9

What can producers do to prevent scours?

Answer 9

-avoid crowding
-avoid commingling neonates and older calves during calving season
-vaccinate at 6-8 weeks pre-calving
-calves must consume adequate colostrum

Question 10

What is the greatest danger to the health of a neonate calf born on pasture?

Answer 10

A herd mate that is greater than or equal to 2 weeks old

Question 11

When should you move pregnant cows away from lactating cows with calves?

Answer 11

15 day intervals during the calving season

Question 12

What are the benefits of replacing old bulls with young bulls?

Answer 12

-Maximize the rate of genetic improvement
-minimizes inbreeding

Question 13

How much of genetic changes in most cow-calf herds do bulls provide?

Answer 13

90%

Question 14

How many calves per year does bull management affect?

Answer 14

15-40 calves/yr.

Question 15

If heifers are retained, how long will bulls influence the herd genetics?

Answer 15

Greater or equal to 10 years

Question 16

How much are bull purchase prices?

Answer 16

$3,500 to $7,500

Question 17

How much is the annual maintenance cost for bulls?

Answer 17

$1,000 to $1800

Question 18

What is a bulls service life expectancy?

Answer 18

3-5 years

Question 19

What is the serving capacity per breeding season for each bull?

Answer 19

About 25 cows on average

Question 20

When selecting a sire what are their genetic values estimated by?

Answer 20

1) phenotype
2) individual performance (growth and scrotal performance)

Question 21

What is “Expected Progeny Difference (EPD)”?

Answer 21

Provide estimates of genetic value of an animal as a parent in relation to other animals of the same breed

Question 22

What is “EPD Accuracy”?

Answer 22

Estimated precision of an EPD value of 0.00 to 1.00

Question 23

What are the 5 steps when selecting herd sites?

Answer 23

1) Assessment of herd records
2) Defining operational needs
3) Recognize genetic tradeoffs and environmental limitation
4) define operational philosophies
5) make your choices wisely

Question 24

When assessing herd records what 3 characteristics should you look for?

Answer 24

1) reproductive success rates
2) weaning and yearling body weights
3) carcass merit

Question 25

What makes up defining operational needs?

Answer 25

-bulls with strong maternal traits for use on heifers
-bulls with strong maternal traits for use on cows
-bulls with strong terminal traits for use on cows

Question 26

What is the rate of genetic change?

Answer 26

1/n (n=number of traits being simultaneously selected)

Question 27

We should recognize that most traits associated with what 3 traits tend to respond slowly to selection?

Answer 27

-fertility
-health
-longevity

Question 28

Define “Maternal System”

Answer 28

Cow size and milk production are matched with feed resources, bulls of moderate biological type are selected and replacement heifers will have similar attributes to mature cows

Question 29

Define “Terminal-Sire System”

Answer 29

Cows are mated to large, high carcass merit bulls, all calves are sol, and replacement heifers are purchased

Question 30

Define “Combination System”

Answer 30

-replacement heifers are produced by mating bulls with maternally-desirable traits to young cows and heifers
-Cows greater than 4 yrs. Old are mated to terminal sites and all calves are sold

Question 31

What is heterosis?

Answer 31

cross bred cows can make measurable improvement in genetic traits such as fertility, longevity, and health in comparison to their parents.

Question 32

Define “Purebred System”

Answer 32

Supply single-breed or composite-breed bulls and heifers as seedstock for commercial cow-calf production

Question 33

Define “Crossbred System”

Answer 33

Leverage hybrid vigor (heterosis) for added production efficiency.

Question 34

What are the different levels of heterosis expression?

Answer 34

• low expression (0-5%) with carcass traits and mature size
  -moderate expression (5-10%) with growth, WW, YW, and milk
  -high expression (10-30%) with fertility, health, and longevity