Bull Fertility

Question 1

1. What is the purpose of a Breeding Soundness Examination in the bull?
2. What does fertility require?

Answer 1

1. • Infertility investigation.
     - Pre-purchase.
     - Pre breeding season
2. • Libido.
     - Erection.
     - Protrusion of penis.
     - Intromission.
     - Ejaculation.
     - Fertilisation.

Question 2

General procedure of Breeding Soundness Examination.

Answer 2

History.
(Test mating).
CE.
Semen collection and evaluation.
Prognosis.

Question 3

Causes of loss/lack of libido.

Answer 3

Breed variation.
Variation within breeds.
Age.
Bullying by females or other males.
Noise and distractions.
Unusual environments.
Boredom.
Lack of exercise.
Overweight.
Overuse.
Severe debility.
Intercurrent disease.
Pain.
Rupture of corpus cavernosum penis.
Uncertainty about foothold.

Question 4

1. What would cause hesitance for a bull to mount?
2. What would cause failure to exteriorise penis?

Answer 4

1. Painful musculoskeletal lesion.
   Penile fibropapillomata.
2. Peripenile, preputial adhesions.
   Phimosis.
   Stenosis of preputial orifice.
   Impotence.
   Spiral deviation within prepuce.
   Congenitally short penis.

Question 5

1. What could cause failure of intromission?
2. What could cause intromission but no thrusting?

Answer 5

1. Deviation – spiral, ventral.
   Persistent penile frenulum.
2. Damaged dorsal nerve of penis. e.g. haematoma

Question 6

1. Examination of the penis.
2. What abnormalities could be found on examination of the penis?

Answer 6

1. Examine before and after mating.
   Administer xylazine.
   Pudendal nerve block (difficult to do).
2. Frenulum, hair rings, scar tissue, growths, lacerations, urethral fistual, preputial prolapse, haematoma, premature coiling.

Question 7

1. What causes penile haematoma?
2. Signs of penile haematoma.

Answer 7

1. Sudden angulation of the penis, causing the tunica albuginea of corps cavernosum to tear at dorsal aspect of distal bend of sigmoid flexure, then a haematoma forms.
2. • Swelling cranial to scrotum.
     - Stiff, short stride.
     - Temporary oedematous eversion of prepuce.
     - 50% cases – abscessation.
     - Initial reluctance to serve, then inability to extrude penis.

Question 8

Prognosis of penile haematoma.

Answer 8

Infection – abscessation, adhesions.
Damage to dorsal nerve of penis.
Vascular shunts from cc to dorsal veins.

Question 9

1. When is spiral deviation of the penis abnormal?
2. What is normal? – why does this happen?

Answer 9

1. Before intromission.
2. Penis deviates ventrally and to the right after intromission – increases contact between penis and vagina to stimulate ejaculation.

Question 10

Signs of spiral deviation of the penis.

Answer 10

Failure to extrude penis – spiralling within prepuce/spiralling once cows hindquarters touched.
Deviation may not occur at every service.
Sudden/gradual onset.
Young/previously normal bulls.
Genetic??

Question 11

1. What is phimosis?
2. Causes?
3. Treatment of phimosis?

Answer 11

1. Stricture of preputial orifice – penis cannot be extruded.
2. Injury or infection.
3. Remove wedge from orifice.

Question 12

1. What is paraphimosis?
2. Risk?
3. What could constriction be due to?
4. Prognosis?

Answer 12

1. Inability to withdraw penis into prepuce.
2. Strangulation of penis.
3. Hair rings.
4. Guarded.

Question 13

1. What is balanoposthitis?
2. What is balanoposthitis associated with?

Answer 13

1. Inflammation of penis and prepuce.
2. Non-specific infections, trauma.
   IBR-IPBP, mycoplasma, ureaplasma.

Question 14

1. What is fibropapilloma?
2. Signs of fibropapilloma?

Answer 14

1. Same virus that causes skin warts. Can be singular or multiple. Seen in young bulls. May resolve spontaneously.
2. Bleeding at service/blood on vulva.
   Pain at intromission so refusal to serve.
   Phimosis/paraphimosis.
   Surgical removal possible. NB haemostasis.

Question 15

1. What is impotence?
2. Causes of impotence.

Answer 15

1. Erection insufficient to allow intromission die to escape rote of blood in cc e.g. shunts. OR blockage in proximal penis prevents blood reaching distal part.
2. • Congenitally abnormal large distal veins draining cc w/in body of penis.
     - Cc drained by distal network of small veins.
     - Cc drained by veins which develop at site of traumatic injury to tunica.
     - Dorsal canals of cc blocked by fibrous tissue, haematoma or thrombus.
     - Diagnosis and treatment difficult.

Question 16

Basic procedure of bull fertility CE.

Answer 16

Body condition score.
Musculoskeletal system.
Penis and prepuce.
Scrotum, testes and epididymis.
Accessory sex gland.

Question 17

What to check when checking musculoskeletal system.

Answer 17

• Observe gait and posture.
• NB hindleg conformation – genetic.
• Look for lameness as cows can go undetected as do not move around much, cows not mounted successfully – infertility, cows not mounted as frequently – low fertility.

Question 18

What are you looking for when checking the prepuce?

Answer 18

• Adhesions – injury, haematoma.
• Orifice – size, secretions, lesions.
• Pendulous prepuce – predisposes trauma, prolapse.
  Preputial eversion – polled breeds, everts 1-10cm, injury risk.

Question 19

What to look for when checking the scrotum.

Answer 19

Conformation.
Circumference.
- puberty.
- total semen production.
- pathology.
- subfertility / infertility.

Question 20

Factors affecting scrotal circumference.

Answer 20

• Age:
  – young increase rapidly.
  – Mature increase gradually.
  – old decrease steadily.
• Breed:
  – Later maturing lean types have smaller scrotal circumference.
• Fat.
• Herniae – not common.
• Testicular pathology.

Question 21

What to assess when checking testes.

Answer 21

• Number.
• Size.
• Shape.
• Consistency.
• Relative position.
• Mobility.
• Symmetry of testes and epididymis.

Question 22

1. Methods of assessing the testes.
2. Testicular pathologies.

Answer 22

1. • Visualisation.
     - Palpation.
     - Ultrasound.
     - Biopsy – FNA.
2. • Cryptorchidism.
     - Testicular hypoplasia.
     - Testicular degeneration.
     - Orchitis.
     - Haematocoele.
     - Adhesions.
     - Tumours are rare.

Question 23

Testicular hypoplasia.

Answer 23

Can be unilateral or bilateral.
Heritable defect – recessive gene.
XXY chromosome.
Presentation:
- Small firm testes.
- Small epididymis.
- Small scrotum.
- Normal libido.

Question 24

1. Testicular degeneration.
2. signs.
3. Causes.

Answer 24

1. Failure of spermatogenesis.
   Partial/complete.
   Transitory / permanent.
2. Signs:
   - Flaccidity.
   - Immature and malformed spermatozoa fibrosis of seminiferous tubules.
3. Increases in temperature due to:
   - Local or general infection.
   - Local inflammation (trauma).
   - Inguinal hernia.
   - Excess lying down.
   - Scrotal dermatitis.
   - Excess scrotal fat.
   - Varicocoele.
   - Cryptorchism.
   Severe nutritional deficiency.
   Transport stress.
   Age.
   Trauma –> ischaemia.
   Extremes of temperature.
   Congenital occlusion of efferent ductules > back pressure > oedema > degeneration.
   Autoimmunity.
   Toxins.

Question 25

Explanation for enlarged testicle.

Answer 25

Orchitis.
Abscess.
Haematoma.
Rarely neoplasia.

Question 26

1. Orchitis.
2. Causes.
3. Signs of associated inflammation.
4. Treatment.
5. Prognosis.

Answer 26

1. Usually unilateral.
   Often w/ periorchitis and/or epididymitis.
2. Caused by haematogenous / ascending / penetrating wound.
   Often infection of T. pyogenes: Strep. (Brucella).
3. Classic signs of inflammation:
   - degeneration, fibrosis, adhesions (abscessation).
4. Abx, NSAIDs, unilateral castration.
5. Always guarded.

Question 27

Problems associated with epididymis.

Answer 27

Trauma.
Infection.
Segmental aplasia.
Congenital occlusion.

Question 28

What can occur as a result of epididymal occlusion?

Answer 28

Segmental aplasia, acquired defect.
Inspissated sperm accumulate behind lesion, epididymal wall usually ruptures, causing sperm granuloma, building up back pressure in the testicle and eventual testicular degeneration.

Question 29

1. Signs of acute seminal vesiculitis.
2. Signs of chronic seminal vesiculitis.

Answer 29

1. Severe pain (on exam and defaecation).
   Purulent discharge after service.
   Pus in semen.
   Enlarged and firm.
2. Pus in semen.
   Fibrosis (firm).
   Loss of lobulations.
   No pain.
   Usually in older bulls.

Question 30

Methods of semen collection from the bull.

Answer 30

Aspiration from vagina.
Massage of ampulla per rectum.
Electroejaculation.
“Artificial vagina”.

Question 31

Anatomy of artificial vagina.
What to not use?

Answer 31

Outer case.
Access for warm water.
Liner.
Cone.
Semen collection tube.

DO NOT USE RUBBER BAND!

Question 32

1. What to assess when evaluation semen.

Answer 32

1. Volume.
   Colour.
   Wave motion.
   Progression of sperm.
   Linear motility.
   Live : dead ratio (Nigrosin-Eosin).
   % abnormalities.

Question 33

Prognosis of sperm evaluation.

Answer 33

Needs > or equal to 2 checks before able to give prognosis.
Measuring potential to sire calves.
Only true test is calves on the ground.

Question 34

1. How is semen sexed?
2. % chance of sexed semen producing female progeny?
3. Disadvantage of sexed semen.

Answer 34

1. Flow cytometry to sort sperm cells.
   F sperm cell contains 3.8% more DNA than M sperm cell (extra leg on X).
   Extra DNA can be detected by laser to provide F sperm cells with electrical charge, diverting their flow into separate receptacle.
2. 90%
3. More costly.