Bull Fertility Flashcards
How can you definite a fertile bull?
Gets 60% of healthy, cycling females pregnant in the 1st 3w
Gets 90% of them pregnant in the 9 week breeding period
What should be the conception rate of a normal fertile bull?
60%
What should you examine during a bull breeding soundness exam? 1. General clinical examination
General clinical exam
- condition score 3 or 3.5 ideal
- check locomotion - lameness and back pain will reduce mounting
- conformation - unusual conformation predisposes to lameness
- ocular assessment - need to be able to see
- teeth - ocular or undershot jaw - heritable
What should you examine during a bull breeding soundness exam? 2. Reproductive tract examination
Scrotal circumfernce
Testicles and associated structures
Penis and prepuce
Accessory sex glands - rectal palpation of prostate and seminal vesicles, rule out seminal vesiculitis
What should you examine during a bull breeding soundness exam? 3. Semen evaluation
Gross motility
Linear progressive motility
Morphology
White blood cells
What is the most commonly used method of semen collection?
Electro-ejaculation
- poor volume and concentration
- welfare issue
What should you evaluate in semen?
Gross motility - grade 3 or above is acceptable (1-5)
Linear gross motility - how many move progressively
Morphology - make a smear - more than 70% normal
Make a smear to assess for WBCs - stain with methylene blue
- seminal vesiculitis
How can you libido test a bull?
Put it in will a female in oestrus
Should serve her within 20mins, ideally within 10
How does a penile haematoma present?
Swelling
Abscess and adhesion formation
Poor px
How can you treat penile haematoma?
Likely to recurr - cull
Cold hose for 4 days, then 3 weeks of warm hosing and massage
Antibiotics and NSAIDs to prevent abscessation
Surgery to remove blood clot if medical management fails
How does a penile papilloma present and what should you do about it?
Young bulls
Interferes with service
May spontaneously regress, but if not
Surgical removal is indicated
How should you treat a persistent frenulum?
Surgical removal
Don’t use for breeding - heritable
How long will it take for the sperm count to recover after a disease?
60 days
Where are the seminal vesicles located?
Either side of midline on rectal examination
What are some venereal disease spread by the bull?
Campylobacter foetus venerealis
Trichomonas foetus
BHV1
What are the signs of trichomonas foetus in a herd?
Bulls are a symptomatic carriers
Prolonged return to service interval
Poor fertility in cows
Abortion in first 2-4m
How is campylobacter foetus venereallis spread?
Bull is persistently infected - epididymal crypts
What are the clinical signs of campylobacter foetus venereallis?
Seen in naive heifers
Endometritis after first service
Failure to conceive
Late embryonic death and irregular return to service
Abortion at 4-5 months of gestation
How can my you treat Bulls for campylobacter?
Wise to cull - persistently infected
Can try long term streptomycin or preputial washes with pen/strep
How can you control campylobacter in a herd?
Use AI for at least two years
Separate infected from non-infected herds
Use a virgin bull
Vaccination - autogenous
What should a farmer consider when reading a Bulls proof?
- Production traits - milk yield, protein and fat
- Profitable lifetime index - fertility, SCC, udder conformation, locomotion, lifespan
- Conformation traits - eg udder and pelvic conformation
- Management fitness traits
- calving ease
- production life
- lifespan
- fertility index
- maternal calving ease
- direct calving ease
- total performance index
What are the advantages of AI?
Can use better Bulls More compact calving period Disease control - campylobacter Safer as you don't have to keep a bull No bull costs Heat detection devices can be used
