Lecture 5: Bovine Andrology (Risco)

Question 1

Reproductively sound bull can:

Answer 1

detect fertile cow, breed her, and deposit fertile semen in anterior vagina

Question 2

requirements for reproductively sound bull**

Answer 2

• physically sound and in good health
• have functional repro system
• have strong libido and fertile spermatozoa
• free of venereal diseases

Question 3

what percent of dairy herd in U.S. use natural service?

Answer 3

20% (majority use combo of natural service and AI)

Question 4

Most common sites of repro tract lesions/problems in bull

Answer 4

Scrotum (i.e. scrotal lesions affect thermoreg, quality of sperm)
Testicle (ie. orchitis)
Epididymitis
Accessory sex glands (i.e. seminal vesicle prone to seminal vesiculitis)
Penis (i.e. fibropapilloma, penile hematoma)
Prepuce (i.e. prolapse)

Question 5

minimum recommended normal morphology %

Answer 5

70%

Question 6

minimum recommended normal motility %

Answer 6

30% or “fair”

Question 7

ideal bull:non-pregnant cow ratio in pasture breeding***

Answer 7

1:25

Question 8

how long is breeding season in beef cattle?

Answer 8

~90 days

Question 9

when should bulls be bought? age, etc?

Answer 9

• virgin bulls
• at least 60 days before breeding season
• at least 15 mo. of age
• temporarily quarantine
• allow to adjust to ration

Question 10

breeding soundness evaluation includes:

Answer 10

PE
exam of repro tract
venereal dz testing
libido testing?
*a production tool*

Question 11

BSE can increase pregnancy percentage by how much?

Answer 11

5-10%

Question 12

BSE consists of:

Answer 12

ID and history (of o and bull)
PE
repro exam
collection and exam of semen

Question 13

what should be included in BSE PE?

Answer 13

structural soundness
BCS
eyes
feet/legs
wounds, physical defects
generalized dz
rectal exam of internal genitalia
external genitalia

Question 14

internal genitlia rectally palpated on BSE PE:

Answer 14

prostate
seminal vesicles
ampulla
inguinal rings
*assess for size, shape, consistency*

Question 15

external genitlia palpated on BSE PE:

Answer 15

scrotum, testes
spermatic cord, epididymides
penis/prepuce (sheath)

Question 16

Know which animal has which sex organs***

Answer 16

• all males have prostate gland

- know which have seminal vesicles: bulls,…

Question 17

accessory sex glands rectally palpated on BSE PE:

Answer 17

seminal vesicles
ampulla
prostate
bulbourethral glands

Question 18

T/F: bull rarely suffers from any problems in the prostate gland

Answer 18

T (unlike dogs)

Question 19

only frequently diagnosed disease of the bovine accessory sex glands

Answer 19

seminal vesiculitis

Question 20

how is seminal vesiculitis diagnosed?

Answer 20

per rectum and by precipitate and cells in semen.

Question 21

how is seminal vesiculitis likely spread?

Answer 21

hematogenously (i.e. actinobacillus)

Question 22

abnormalities of the penis and prepuce

Answer 22

• neoplasia
• persistent frenulum
• prolapsed prepuce
• hematoma
• skin separation
• laceration

Question 23

fibropapilloma

Answer 23

papilloma common on young bull penises

• most mild cases clear after excision
• no good vax available
• NOT a venereal disease

Question 24

tx for penile hematoma

Answer 24

3-4 mo. rest; may need to be surgically corrected

-often followed by prolapse of prepuce

Question 25

prolapsed prepuce

Answer 25

- most common in bos indicus breeds - injury to preputial tissue with edema - sequel to hematoma of penis - can be congenital preputial abnormality tx: sling, abx, 2-5 mo. rest, circumcision procedure

Question 26

the most easily reproducible measurement for testicular mass (parenchyma) in the bull***

Answer 26

scrotal circumference

Question 27

scrotal circumference highly correlates to:***

Answer 27

testicular size, sperm production

Question 28

testicular mass reflects:***

Answer 28

parenchymal mass

Question 29

benefits to beef herd in using bulls with large scrotal circumference

Answer 29

- earlier puberty in daughters and sons - reduced probability that bulls suffering from testicular hypoplasia or degeneration will be mixed with the breeding herd

Question 30

Exam Q: given 17 mo. old bull with scrotal circumference of 29 cm, fail or pass BSE?***

Answer 30

FAIL

Question 31

bulls 15-18 mo. should have what scrotal circumference?

Answer 31

31-32cm

Question 32

bulls 18-24 mo. should have what scrotal circumference?

Answer 32

32-34cm

Question 33

in litter-bearing animals, sires selected for testicular growth produce daughters with:

Answer 33

more active ovaries

Question 34

How does electronic probe work?

Answer 34

pathway involves sacral parasympathetic n. that includes internal pudendal n. *dairy bulls do NOT respond well to this method!

Question 35

How is semen evaluated?

Answer 35

Motility: gross, individual Morphology: % normal/1ary abnormalities/2ary abnormalities, other cells (WBC, RBC,etc.)

Question 36

min. motility threshold***

Answer 36

"fair": generalized oscillation (30%***)

Question 37

minimum recommended threshold for normal sperm morphology***

Answer 37

70%

Question 38

primary abnormalities mostly related to problems in:

Answer 38

seminiferous tubules

Question 39

2ary abnormalities most related to problems in:

Answer 39

epididymis and vas deferens

Question 40

3 classifications of breeding potential

Answer 40

satisfactory unsatisfactory deferred

Question 41

"satisfactory" breeding potential

Answer 41

- meets or surpasses the minimum thresholds for scrotal circumference, sperm motility, morph. - does not show genetic, infectious, or other problems or faults which could compromise breeding or fertility

Question 42

"unsatisfactory" breeding potential

Answer 42

- below one or more thresholds AND highly likely to ever improve! - and/or shows genetic faults or irrevocable physical problems (including infectious dz) which would compromise breeding or fertility (i.e. lameness, pink eye)

Question 43

"deferred" breeding potential

Answer 43

- bulls that don't fit into above categories and may benefit from re-test - bulls substandard but have capability to improve (i.e. very young bulls with low BCS)

Question 44

most common reason for deferring a bull**

Answer 44

heat stress - increases the number of abnormal sperm (usually 2ary) and dec. motility - cold stress can have same effect up north