Replacement Heifers

Question 1

Goals of replacement program

Answer 1

Puberty by 12m
Puberty 42d before start of breeding season
Calve by 24m 
Breed heifers 4wks before cows
Calve early in first calving season
Retain high % as pregnant mature cows
Improve second parity pregnancy %

Question 2

Faster gaining breeds

Answer 2

Puberty at older age, Charolais

Question 3

Slower gaining breeds

Answer 3

Puberty at younger age, angus

Question 4

Breeds selected for milk

Answer 4

Puberty younger age, Simmental

Question 5

EPD

Answer 5

Prediction of transmitting ability

Question 6

Heifers born early

Answer 6

Higher % puberty and pregnant

Question 7

Older heifer calves

Answer 7

Greater feeding and management flexibility

Question 8

Puberty wt

Answer 8

55-65% of mature

Question 9

Reproductive tract score RTS

Answer 9

Subjectively determines inset of puberty
Size of uterus, ovaries by transrectal palpation
5-pt scale
Evaluate 8wks before breeding season

Question 10

If many heifers RTS of 2

Answer 10

Improve nutrition, delay breeding season, breed 6m later, market heifers and find replacements

Question 11

Pelvic area measurement

Answer 11

1yr and 2yr. R:0.7

Question 12

Pregnancy diagnosis

Answer 12

40d post breeding

Select only those that conceive

Question 13

First ovulation

Answer 13

Usually not signs of heat…priming

Question 14

Ionophore (monesin)

Answer 14

Increase #pubertal heifers by start of season
Decrease age at puberty
Changes in ruminal fermentation (propionic acid production)

Question 15

Nutrition: breeding through mid gestation

Answer 15

65% mature weight at breeding
85% at calving
ADG 1.3-1.5 lb/day 1.5lb/d cracked corn for energy
Supplement protein if low qual forage (over feeding –> low fertility)

Question 16

Nutrition last 60 d

Answer 16

Demands increase

Greater BCS at calving - higher# heifers peg 40-60d of next season. Dominating factor in postpartum fertility.

Question 17

Nutrition: 80d of lactation

Answer 17

Heifers grow at .5lb/d
Requirements increase by 20%
Difficult to add BCS in lactation

Question 18

Brucellosis

Answer 18

Eradicated except for Wyoming and Montana
RB51- long term cell med
If 1 pos, need 2 consecutive neg months

Question 19

IBR BVD

Answer 19

MLV 2-3x after weaning before breeding

Quarantine for 30d

Question 20

Lepto

Answer 20

Chronic kidney infection (excreted in urine)
Host: skunk, raccoon, opossum, fox, mice, deer
V 2x pre breeding, booster mid gestation and annually
Away from water sources

Question 21

Campylobacteriosis

Answer 21

AI, young bulls
Vx heifers after 6m 2-3x
Booster annually 30d before season
Vx bulls 2-3x at arriving, 30d before breeding

Question 22

Trichomoniasis

Answer 22

Vaccination????
Test bulls, cull positives, keep closed herd
Synchronize and AI

Question 23

Histophilus

Answer 23

Vulvitis, vaginitis

Vx 2-3x and annual booster

Question 24

Preg dx after 2nd breeding

Answer 24

Goal: 90-95% preg and early
CCP: BCS 5.5 at preg dx, calving with 85% and 6-6.5

Question 25

Not meeting rebreeding goals

Answer 25

Check bull fertility, forage quality and quantity, supplement during first lactation, infections

Question 26

Start of 2nd breeding season

Answer 26

CCP: BCS 5.5-6, 82-84% mature wt | Depends on: adequate BCS at calving time, forages postpartum, supplement to meet energy needs during lactation

Question 27

First calving

Answer 27

>65% during first 3wks. >80% during first 6wks. <2% At start of season 6.5. 80-85% mature wt after parturition If CCP not met- supplement after calving

Question 28

Pregnancy after 1st breeding

Answer 28

90-95%. BCS >5 | Low %--- bull fertility, nutrition, repeat bedding

Question 29

Yearling

Answer 29

Tested 30-60d before breeding season 55-60% mature wt. RTS = 4. 60% heifers pubertal 30-60d before season. Didn't meet goal: increase energy, delay season, sell

Question 30

Weaning

Answer 30

In spring for fall calving herds Wt and age affect nest of puberty Use Ionophores, anthelmintics Select heifers to meet: mature size, growth rate, milking ability, calving ease