Bull fertility

Question 1

What are the components of a bull MOT (4)

Answer 1

• look from a distance (vision, weight bearing)
• look when restrained (any ocular discharge, testes, shaft any kinks?)
• semen collection
• (good to assess at serving as pbs may still occur!)

Question 2

what makes a bull fertile (4 factors)

Answer 2

• libido and physical fitness
• production of high quantity / high quality sperm
• ability to deposit semen in the vagina
• absence of disease that could be transmitted ie BVDv and campylobacter

Question 3

When should you conduct a bull MOT

Answer 3

10weeks before breeding season (gives us time for bull to make new sperm or find a replacement bull)

Question 4

What do you look at in semen ?

Answer 4

• colour (cream colour is ideal, not too light / too dark)
• motility
• ratio of dead sperm

Question 5

Percentage of bulls failing BBSE

Answer 5

• 30-40%

Question 6

why not just increase number of bulls and have bull rotation?

Answer 6

• hides subfertile bulls
• increases bull cost per calf
• increases bull to female ratio increase cost!

Question 7

why does fat deposition in testicles affect fertility?

Answer 7

• increase in heat! reduction in thermoregulation

Question 8

does plane of nutrition significantly affect fertility of bulls?

Answer 8

Yes affects libido, sperm motility, and

Question 9

What makes up a BBSE?

Answer 9

• BCS
• musculoskeletal system
• ocular/ vision
• incisor/ dental pad alignment
• internal accessory organs ( assess for seminal vesiculitis-)

Question 10

If a young bull has seminal vesiculitis what may you find in the semen?

Answer 10

• blood and pus

Question 11

What are you looking for when assessing the scrotum?

Answer 11

• scrotal circumference (very heritable)
• tone
• lack of lumps
• symmetry
• skin pliable with no thickening

Question 12

Is scrotal circumference heritable?

Answer 12

yes yes it is

Question 13

what are common abnormalities involving the penile sheath?

Answer 13

• deviation
• trauma
• fibro-papillomata
• balanoposthitis

Question 14

scrotal circumference is correlated to…

Answer 14

sperm motility and morphology

Question 15

What magnification do you need to look at sperm?

Answer 15

X100- X400

Question 16

Semen can be assessed for

Answer 16

• gross motility
• progressive motility
• morphology

Question 17

Foot trimming of bulls- should be routine or not routine?

Answer 17

routine

Question 18

Name some penile and Preputial Abnormalities/Injuries that may prevent a bull from serving.

Answer 18

• corkscrew penis
• hematoma
• preputial tearing
• diffuse swelling
• viral papillomata
• adhesions preventing penil extrusions

Question 19

What are the scrotal circumference targets for bulls?

Answer 19

• 32 cm at 18month minimum
• 34 cm at 2 yrs minimum

Question 20

Name two disease processes that can affect the testes..

Answer 20

• orchitis
• epidydimitis (swelling and blockage of the ducts )

Question 21

Orchitis first causes…. then… of the testes

Answer 21

swelling/ degeneration

Question 22

Name two methods for semen collection

Answer 22

1) electro-ejaculation
2) artificial vagina

Question 23

why do we need to carry out a rectal for a bull breeding Soundness exam?

Answer 23

• to assess the internal accessory sex glands (i.e seminal vesiculitis)

Question 24

What is the risk of hiring a bull?

Answer 24

• risk of venereal disease

Question 25

What steps should a bull programme include

Answer 25

• ensure vaccination/ worming
• check for lameness and ensure regular foot trimming
• ensure 10 wks before breeding season bull is examined
• monitor BCS
• Monitor bull performance during the breeding period by careful observation of mating and recording return rates

Question 26

How long should bulls be with the beef cows?

Answer 26

9-12 weeks

Question 27

if a bull is 18months old can serve how many cows in a month

Answer 27

18 cows

Question 28

Target % of cows to become pregnant by a bull

Answer 28

95% of cows should become pregnant

Question 29

what may happen if a bull is near another bull during service?

Answer 29

may stop bull from serving

Question 30

Name some diseases bulls can get routinely tested for

Answer 30

• BHV (repro/ resp)
• lepto
• BVDV
• Johnes

Question 31

How do you test a bull for Campylobacter?

Answer 31

• 3 preputial washes- need to test negative for all thress

Question 32

How does Campylobacter affect cows?

Answer 32

• causes empty cows

Question 33

How do you test for Johnes?

Answer 33

• usually prescreened and herd is assessed as low risk
• test for Ab

Question 34

what stain can you use to assess sperm morphology? what does it mean if sperm are pink?

Answer 34

• eosin- Negrosin
• pink means they are dead

Question 35

What are cytoplasmic defects seen on sperm mean?

Answer 35

• bull is still too immature- not ready to serve

Question 36

How do you treat a hematoma of a teste?

Answer 36

• leave it to self-heal

Question 37

What infectious notificable disease may cause orchitis in a bull?

Answer 37

Brucellosis

Question 38

Is a preputial prolapse normal?

Answer 38

• some breeds can be more predisposed

Question 39

if prepuce can never come out- what can you do?

Answer 39

• put in ice

Question 40

electroejavulation can sometimes do what to the penis?

Answer 40

Cause it to corkscrew