3 – Breeding Management

Question 1

What are the first meat breeds in Canada?

Answer 1

• Black angus
• Herford: older breed now
• (shorthorn)
• *hardy and tough (‘less groceries’)
• European came later: Simentals
  o Bigger and can be dual purpose
  o Require more resources

Question 2

Management of newborn

Answer 2

• Ensure adequate colostral intake
• Ensure calve is mothering calf
• Vit E/Selenium
• Dip Navel
• ID tag
• Record birth weight
• Dehorn/castrate <7 days of age
  o Next option at 1-2 months

Question 3

What do you do for calf management at ‘turn out’ (usually 1-2 months old)

Answer 3

• *want to vaccinate as maternal Abs decreased
• For sure: Clostridial vaccines
• Maybe:
  o Initial H. somnus vaccination
  o Other respiratory vaccines (M. hemolytica, P. multocida, INTRA-nasal vaccines)
• Dehorning and castration if required
  o Hard to castrate at birth
• Growth implant for steer calves
  o Many don’t’ do in heifers as can affect reproduction (as long as over 30d of age!)
• Vit E/Selenium injection

Question 4

Castration in bull calves: why?

Answer 4

• Bull calves are discounted heavily
• NA industry does NOT give high price for bull carcasses
• Intact bulls are difficult to manage
• *Implants at branding/’turn out’ offset weight gain DISADVANTAGE due to castration
  o Ralgro
  o Synovex

Question 5

What are the priority welfare issues?

Answer 5

• Painful procedures
  o Dehorning, castration, banding
• Feedlot health and morbidity
• Weaning methods
• Environmental and housing conditions

Question 6

What are the areas of feedlot health and morbidity?

Answer 6

• BRD
• Lameness
• Nutritional diseases associated with high concentrate feeding

Question 7

Castration: Canadian code of practice and pain control

Answer 7

• Pain control IF older than 6 months of age
  o Next round=likely required to use pain control
• (dairy: use in all calves)

Question 8

De-horning: Canadian code of practice and pain control

Answer 8

• If after horn bud attachment=need to use pain
• (dairy: block and use anesthetic)
  o Likely will be that for the next beef code of practice

Question 9

Castration methods

Answer 9

• LOTS!
• Emasculator
• Newberry knife
• *best to do it as early as possible
  o Elastrator Bander: not pain free, but less pain
  o Can do for older calves: but only if need be
• OLDER: *tetanus concern when use bander=VACCINATE

Question 10

Vaccination of cows

Answer 10

• Modified live IBR/PI3, BVD, BRSV vaccine
• Optional
  o Campylobacter fetus (Vibrio)
  o Leptospirosis
  o H. somnus
• Clostridial vaccine booster for heifers! Maybe also cows every other year
• **at least 30d before breeding season starts

Question 11

What are some other things done prior to breeding season?

Answer 11

• Fly tags
• BCS
• Weigh heifers
• Reproductive tract scoring and pelvic measurements
• Estrous synchronization for heifers
• Bull evaluation +/- Trichomoniasis testing

Question 12

What are the objectives of reproductive management?

Answer 12

• High percentage of cows pregnant
• Maximize weaning weights=calve EARLY
• Uniform calf crop
  o Short breeding season (2 cycles for heifers, 3 for cows)
• Breed heifers to calve as 2-year-olds
• One calf/cow/year over 3-5 reproductive lifetime

Question 13

What are some of nature’s obstacles?

Answer 13

• Fixed gestation length (282d)
  o Cows must conceive within 85 days of calving to calve at the same time next year
• Delay in first estrus due to suckling
  o Suckled beef cows do NOT begin estrous cycles for 40-60d post calving
• Conception rate: 60-70% maximum (if do AI=less)
  o Mother nature=actually pretty good
  o Better than many species (including humans, dogs, horses)

Question 14

What are the risk factors for impaired fertility? 2 areas

Answer 14

• 1. Conception rate
• 2. % of females cycling
     o Many times this is the case
     o Driven by body condition

Question 15

What is done to overcome nature’s obstacles?

Answer 15

• Restricted breeding season
• Breed heifers 3-4 weeks before cows
• Cows at good BCS at time of breeding
  o *need to make sure interval between calving and cycling is NOT extended
• Flushing
• 48hr calf removal
• Heifer management and selection

Question 16

Restricted breeding season

Answer 16

• Provides selection pressure for cow fertility
• Reduction of 25-50lbs in calf weaning for every 21d later in calving season
  o Want 60% of herd to calve in first 21d! (need to conceive in first 21d)
• *simplifies management strategies: nutritional management and vaccine protocols

Question 17

Calving distribution and profit: research

Answer 17

• Decrease length if calving season=huge difference in increasing profit

Question 18

Breed heifers 3-4 weeks before cows: why?

Answer 18

• Longer anestrous period after calving
• More likely to have dystocias
• Likely to mismother
• Have less colostrum and calves are more at risk for failure of passive transfer
• Have lower milk production

Question 19

Cows in good body condition at time of breeding

Answer 19

• Minimum BCS of 2.5
• *require sorting at weaning time to adjust BCS after calving
• High demands of lactation make it difficult to ‘catch up’ after calving
• Thin cows=less are cycling=take LONGER
• Good weight=most cycling at 60d (91% vs. 50% in the thin calves)
• If calved in second 21=good cows good chance, but moderate and thin cows are LESS likely
• If calved in 3rd window: very unlikely to be cycling even if in good body condition

Question 20

Flushing

Answer 20

• Feed cows increased energy ratio so they gain weight just PRIOR to breeding season
• *cows in positive energy balance=more likely to cycle and conceive
  o Those with above average weight gains were 2x more likely to be pregnant

Question 21

48 hour calf removal (not used in most herds)

Answer 21

• Difficult management procedure
• Removes effect of suckling to ‘kick start’ estrous cycles on cows
• Variable results with research trials
• May work better on cows in poorer body condition

Question 22

Management program for heifers

Answer 22

• Raise heifers to reach TARGET WEIGHTS
  o 65% of mature weight at breeding
  o 85% of mature weight at calving
• Feed appropriate ration
• Select heifers from early calvers

Question 23

Heifer selection

Answer 23

• 15-20% of cow herd replaced each year
• Need to select 35-50% more heifers than required at weaning
  o Allows for culling of poor yearling weights and those that don’t conceive
• *usually equates to keeping 50% of heifer calf crop

Question 24

Heifers and time to re-cycle after calving

Answer 24

• 82-100d until first breeding period
• NONE cycling by start of next breeding period
  o Even those perfectly good and fertile
  o **highest open rate will be in second calvers
• **BREED HEIFERS AHEAD OF COW HERD (~30d prior)

Question 25

Heifers are important in improving productivity

Answer 25

- Productivity is improved when a high % of heifers conceive early in first breeding season - *establishing momentum - Need to be cycling at 12-13.7 months of age (born in first 42 days of breeding season)

Question 26

Breeding soundness of bulls

Answer 26

- Testicular and scrotal development - Semen quality and volume - Ability to physically breed females - Libido or serving capacity

Question 27

What is an appropriate bull:cow ratio?

Answer 27

- Yearlings: 15-20 - 2 years: 20-30 - 3+ years: 30-40

Question 28

Scrotal circumference

Answer 28

- Max testicular size reached by 4-6 years of age - By 12-14 months=bulls should have reach minimum scrotal circumference (32cm) o If low as a yearling=usually low at maturity as well - **those with a greater scrotal circumference=make female reach puberty sooner

Question 29

If 32cm circumference at 24 months: how many pass later on?

Answer 29

- 13% pass

Question 30

if 38cm circumference at 24 months: how many pass later on?

Answer 30

- 88% pass

Question 31

Number of calves the bulls actually sire

Answer 31

- HUGE variability o Likely due to libido and dominance, etc. - No testing currently - Would be useful to know those

Question 32

Cow calf and technologies

Answer 32

- Pretty low tech - *SPARSE USE - ½ do individual records - Only 20% have computer records - Average: 2 vet farm visits o 1. Preg check (fall) o 2. Semen testing (spring) - Only 50% preg checked their cows - Only 25% implant calves - *management strategies are NOT widely adopted in the industry (due to most being ‘hobby herds’)

Question 33

So what can we do to add value to the calf-cow industry? (besides preg check and semen)

Answer 33

- Continued education (many clinics now do it for free) o Grazing management - RECORD KEEPING and analysis (hard to know how to charge for that) o Got used to charging for physical tasks vs. brain

Question 34

Charging for services right now in calf-cow industry

Answer 34

- ex. if cost per post-mortem, there worst day=your best day - IF do RETAINER FEE: you are now in alignment o You are trying to preventing the bad days from happening and they still pay you - “can also shop around”

Question 35

Grazing management

Answer 35

- KEY - Maintaining a plant community requires SKILLFUL management - Rotational or time controlled=popular and improves profit