Unit 6 - Pre-breeding Management Flashcards
What is the focus?
Recovery from calving and preparing for breeding season
What are the 7 key activities?
1) nutritional support for peak lactation and ensuing breeding season
2) evaluation of udder quality
3) vaccination against leptospirosis and vibriosis
4) verification of breeding soundness
5) physical conditioning for breeding season
6) Turnout on breeding pastures plus parasite control
7) ovulation synchronization
What are the 4 major functions?
1) preserve cow body condition
2) get bulls ready to breed
3) support health
4) synchronize cow estrus cycles
When does nutrition peak for lactation and breeding?
The first 80 days of lactation
Why should nutrient intake keep pace with demand?
To support peak lactation and uterine involution
What can result from body condition loss before breeding?
Delayed conception
What are the scoring guidelines when evaluating udder quality?
1) observe and score within 24 hours after calving
2) Assign scores based on the appearance of the weakest quarter
3) cow age should not be factored into udder scores
4) one person should assign udder scores for consistency
What is the scoring for udder quality?
1 (bad) - 5(moderate is good) -9 (bad)
What is vibriosis?
It’s a venereal disease caused by Camphylobacter fetus ssp. Venerealis.
Can be passed from bull to cow and vice versa. Infected bulls can be chronic carries.
What are symptoms of vibriosis?
1) slow return to estrus
2) poor pregnancy rates
3) abortions at 5-7 months of pregnancy
When should vibriosis vaccine be given to cows, bulls, heifers?
Cows: 30 days pre-breeding annually
Bulls: 75 days pre-breeding annually
Heifers: 75 days pre-breeding
What is leptospirosis?
A contagious bacterial disease, is ubiquitous in cattle and wildlife and is transmissible to humans.
Organism localize in kidneys and are voided in urine (acute, subacute, subclinical)
What are symptoms of leptospirosis?
Fever and abortion
What type of vaccine and when should vaccine be given for leptospirosis?
-vaccine should be a multivalent product and include “L. Hardjo-bovis and L. Pomona”
-cows: 30 days pre-breeding annually
Bulls: 75 days pre-breeding annually
Heifers: 75 days pre-breeding
When should bull breeding capabilities be assessed?
60-90 days before breeding season
Where are breeding capability assessments conducted the most?
Seedstock operations
What does a breeding soundness exam (BSE) consist of?
1) physical exam
2) eval of repro. Organs
3) eval of semen quality
4) eval of libido (not standard)
How long is the spermatogenesis cycle?
61 days
What anatomical parts are assessed during the physical exam?
Eyes
Teeth
Feet and legs
Body condition
What is included in the evaluation of reproductive organs?
1) rectal palpation: of vesicular glands, ampullae, and prostate for evidence of inflammation, adhesions and fibrosis
2) palpation + visual evaluation: of spermatic cord, scrotum, testes, and epididymis for symmetry and evidence of abscesses, injury, frostbite, and tumors
3) Visual evaluation: of penis and sheath for injury, scars and adhesions; verification of full extension of the penis
4) measurement of scrotal circumference as a proxy for semen volume
What are the 3 elements of semen quality evaluation?
1) sperm cell concentration (#/cm^3) - sometimes
2) Motility (% progressively motile) - always
3) morphology (% abnormal cells) - always
How is semen collected and observed for quality evaluation?
It is collected via electro-ejaculation and examined visually.
What is the requirement for passing sperm motility evaluation?
- greater than or equal to 30% progressively motile cells
-rapid swirling = very good
Slow swirling = good
Oscillation = fair
Sporadic oscillation = poor
What is required for sperm morphology to pass evaluation?
-greater than or equal to 70% normal cells.
How is sperm morphology examined and what are their classifications?
- greater than 10 slide fields are examined under 10x magnification
- total cells and abnormal cells are counted in each field
-the location of the abnormality is recorded
-classified as either primary or secondary
Primary defects
-occur during cell maturation!
-common in young sires (less than 12 months) and old sires (greater than 6 years)
-generally result in a bull being culled
Secondary defects
Occur during storage!
-occur during long periods of sexual inactivity
-generally result in a bull being re-tested
What are environmental factors important for physical conditioning?
-should minimize fighting and promote exercise
-spacious pastures preferred
-avoid fence-line contact with females
-avoid placement with larger, more mature bulls
-consider providing bedding for 60-75 days prior to service
What are diet and feeding management factors for physical conditioning?
-bulls are usually over-conditioned at the time of purchase
-unnecessary body condition reduces the ability of the animal to travel and can predispose it to injury
- highly-conditioned bulls have normal fertility and libido when allowed to gradually return to moderate fleshiness before breeding season
What are exercise factors for physical conditioning?
-bulls in service must travel several miles daily over varied terrain to seek estrual females
-maintain bulls in large, topographical rugged pastures; vary placement of water, feed, and mineral to encourage movement
-minimizes fighting and riding behaviors
-critical to managing post-sale body condition and general fitness
When can pastures be considered clean?
Not grazed upon for 30-60 days
When should cows, bulls, and calves be treated for parasites?
As they are moved to “clean” breeding pastures
What are benefits of synchronized ovulation?
-shorter breeding seasons
-shorter calving seasons
-greater weaning weights and calf uniformity in the subsequent year
-improved AI success and efficient
-improved time management
What are the requirements for successful synchronization?
-plan and execute according to a tightly managed schedule
-females must be adequately conditioned and at least 45 days post partum to respond
-reliable, experienced laborers and adequate facilities
-For AI breeding, high quality semen that is carefully warmed and applied
-for natural service breeding, aggressive, and fertile bulls
For the health of the bulls, how should they be handled during natural service breeding?
-be rested or rotated every 24 hours and paired with no more than 15-20 cows each in a small pasture
How do synchronization protocols vary?
-time requirement (1-30 days)
-cow age (mature vs. heifer)
-level of sophistication desired (heat detection vs. timed insemination)
-expense
-AI strategy ( AI vs. natural)
