Bull breeding soundness examination Flashcards
What should a fertile bull be able to do?
- 90% of 50 normal, cycling, disease free, females pregnant within 9 weeks
- 60% should become pregnant within the first 3 weeks of the breeding period
What must the bull be able to do to achieve good fertility in natural service conditions?
- Find cows in heat
- Mount the cow
- Serve the cow
- Produce large amounts of viable sperm
What are the 3 parts to a bull breeding soundness exam?
- General clinical examination
- Reproductive tract examination
- Semen evaluation
What does general clinical exam include?
- condition score
- locomotion + gait
- conformation
- ocular conditions
What does a reproductive tract exam include?
- scrotal circumference
- testicles + related structures
- accessory sex glands
- prepuce + penis
What does semen evaluation include?
- gross motility
- linear progressive motility
- morphology
- white blood cells
What is ideal BCS of a bull at the start of the breeding season?
- ideally 3-3.5
Why would you check for ocular + teeth problems?
+ why do you locomotion score?
- Ocular - detecting cows in heat
- Teeth - may be under/overshot = heritable
- Locomotion score = lame bulls can’t serve as well
Why is scrotal circumference important?
What should it be at 2 years old?
- Scrotal circumference highly correlated with total sperm output
- > 34cm at 2 y/o
What are different methods of semen collection?
- Artificial vagina
- Electro-ejaculation
- Trans-rectal ampullary massage
- Internal artificial vaginal
What must be done prior to elecro-ejaculation?
- 1-2 mins massaging the ampullae
What is the rule of thumb with libido testing?
- If a bull is put with a cow on heat then he should serve her definitely withing 20mins ideally within 10mins
What are specific problems of the reproductive tract?
- Penile and preputial problems
- Problems with the accessory sex glands
- Problems with the testes
- Sexually transmitted disease
What should be done with penile haematoma (broken penis)
- Cull
- Medical Tx = swelling <15cm
-rest for 2 months - cold hosing for 4 days followed by warm hosing and massaging for 3 weeks
- Antibiotics to stop abscess + NSAIDs
- Surgical Tx = removal of blood clot + suturing of tunica albuginea where possible
- followed by medical Tx
What is penile fibropapilloma?
What should be done?
- Caused by bovine papilloma virus
- Most common in young bulls
- May disappear with time - but can interfere with serving so should be surgically removed
- Removal done standing using pudendal nerve block
What are other penile and preputial problems?
- Penile deviations
- Hair rings
- Persistent frenulum
- Preputial injuries
- Preputial prolapse
What are the main venereal diseases in cattle?
- Campylobacter fetus venerealis
- Tritrichomonas foetus
- BHV 1 - IPVV
What are clinical signs of Campylobacter fetus venerealis?
- Endometritis after service
- Failure to conceive
- Late embryonic death
- Abortion (Usually 4-5months)
- Infected cows become immune after few months but may shed for up to 1yr
- Bulls don’t develop immunity - but can treat young bulls with streptomycin
How is campylobacter fetus venerealis diagnosed?
Control?
- Males = sheath washing + culture
- Females = vaginal mucus culture
- Control = use AI for at least 2 yrs, separate infected from non-infected
What is tritrichomonas fetus? What does it cause?
- Protozoan parasite
- Bulls are carriers after transient balanoposthitis become asymptomatic carriers
- Females = may abort (2-4mo), discharge 1wk after service, may lead to pyometra
- NOT IN THE UK
What is IPVV?
- Infectious pustular vulvovaginitis
- Caused by BHV-1
- Venereal spread by carriers
- Not associated with abortion or respiratory disease (Different strain to IBR)
What are clinical signs of IPVV + Dx?
- CS =
- In the cow = mucopurulent vaginal discharge, Inflammation of the vaginal and vulvar mucosa with pustules which become ulcers
- In the bull = Painful swelling of the penis and prepuce
- Dx = PCR, serology
- No need to treat
