Unit 2 - The Production Cycle Flashcards
What’s “Calving Interval”?
The length of time between calving date in the CURRENT year and calving date in the PREVIOUS year for a single cow.
What’s is the average calving interval?
< or equal to 12 months
How do you calculate “Pregnancy Rate”?
(Cows pregnant / Cows exposed for breeding in the current year) x 100
What is the ideal pregnancy rate?
> or equal to 90%
What is “Calving Distribution”
Refers to the proportion of all cows calving during each successive 20-day period of the calving season.
What is the calving distribution proportion ratio in a 60-day season?
60:20:20
(Start of season, middle of season, end of season)
How do you calculate the “ Calf Crop” or aka “Weaning Percentage”?
( calves weaned / cows exposed for breeding the previous year) x 100
How long are postpartum anestrous intervals?
< or equal to 45 days.
During the postpartum interval, do estrus cycles occur?
No. Pregnancy is not possible.
When do estrus cycles resume?
When Uterine involution (repair) is complete.
What should the average calf crop be?
> or equal to 90%
What are the 7 overall goals for cow-calf producers?
1) average calving interval < 12 months.
2) Pregnancy rates >90%
3) Few calving difficulties
4) few neonate health problems
5) Calving distribution at 60:20:20 in 60-day season
6) Postpartum anestrous intervals < 45 days
7) Calf crop >90% (weaning percentage)
How many producers use the “Spring-Calving Herd Cycle” and why?
70%. Spring foraging of cool seasons grass saves on expenses when providing nutrition.
How many producers use the “Fall-Calving Herd Cycle” and why?
30%. Because although nutrition is more expensive at this time, producers market return will also be higher and make up for the price.
Also make pre-calving system simpler.
How long is the Gestation period?
282 days
How long is the Pre-calving period?
60 days
How long is the calving period?
1 day
How long is the Lactation Period?
100 to 270 days
How long is the Pre-breeding period?
60 days
How long is the Breeding period?
45 to 60 days
How long is the Weaning period?
1 to 60 days
How long is the Heifer development period?
1.5 to 2.5 years
What unique challenges do each of the stages of the cow-calf production cycle present?
1) reproduction
2) health
3) nutrition
4) genetics
Describe the Gestation Cycle ( conception-calving)
-coincide with mid and late lactation
-calf is weaned during this period.
- Pregnancy Dx occurs 60-90 days into the cycle.
-Cows are sometimes culled based on performance.
- Cow nutrient intake is MODEST at this time.
- Low-quality forage used.
-Internal and external parasite control given d/t being moved.
Describe the Pre-Calving period
- nutrient requirements are HIGH
- 65-80% fetal growth occurs here
-Body condition needs to be > 5.0 on a 1-9 scale. - Cows are moved into calving pasture.
-Herd sires are selected or purchased during this time.
Describe the Calving period
-nutrient intake is low right before calving, the QUALITY must be increased.
-calf is born
-ensure adequate colostrum intake (passive immune transplant) by calf first 48 hours of life.
- perform neonate health and record keeping
-ensure placenta is delivered
What is “Dystocia”?
Calving difficulty.
What are the benefits of early conception?
1) greater calf weaning weights
2) longer intervals for cows from calving to subsequent breeding.
Describe the Lactation period
-coincide with pre-breeding, breeding, and early gestation
- milk output peaks shortly after calving and declines naturally after
- nutrient requirement VARY with milk output
-cow body condition decreases as lactation length increases
Describe the Pre-breeding period
-coincide with lactation
-cows and bulls vaccinated 30-75 days before
-parasite control applied upon turnout to breeding pasture
- bulls should be examined for breeding soundness approx. 60 days before season because of length of spermatogenesis.
- > 2 full estrus cycles before exposure to breeding
Why might a bull fail breeding soundness?
1) broken sperm cells
2) storage defects
3) will only receive a defer scale on their 1st fail
Describe breeding period
-coincide with mid-lactation
-cows placed in breeding pasture 2 weeks before breeding
- internal and external parasite applied at turnout
-calves are branded, castrated, dehorned, an vaccinated early in breeding period.
-bulls checked daily for injury and adequate libido
How long should producers wait for natural immunization to kick in before trying to do any procedures on calf ?
60 days
What’s the most common cause for a bull to not breed?
A eye injury or infection such as conjunctivitis.
Describe the weaning period
-lactation ends abruptly
-calves are vaccinated twice for Clostridial and respiratory diseases.
-calves learn to eat feed and drink water
-calves treated for internal and external parasites
- weaning management is highly variable in the U.S.
Describe heifer development period
- potential heifer replacements selected
- replacements are vaccinated for vibriosis
And brucellosis ( must be given by vet)
-heifers fed to achieve 55-65% mature weight by first breeding (12-14 months)
-heifers are bred 15-30 days earlier than mature cows
What traits are used to select replacement heifers?
1) birth date
2) sire
3) conformation
4) thriftiness
5) weaning weight
