Bull Flashcards
what are the parts of the breeding soundness exam?
general physical exam
reproductive exam
collection and examination of semen
do we use a breeding soundness exam to rank bulls for fertility?
no
bar for bull to meet to be satisfactory potential breeder
what important things are not part of a standard breeding soundness exam?
libido
mating ability
venereal disease
what do you examine for the reproductive tract in a bull?
scrotal circumference
external genitalia
internal genitalia
what accessory sex glands do bulls have?
ampulla
seminal vesicles
prostate
bulbourethral gland
where is there usually swelling due to broken penis?
underline
what do you look at for the scrotum and testes?
mobility in scrotum
resiliency- turgidity
symmetry
size
epididymides
skin lesions
what does scrotal circumference correlate with?
sperm production
what are some scrotal skin lesions?
scrotal dermatitis
scrotal frostbite
what is the minimum recommended scrotal circumference for bulls more than 24 months?
34 cm
what should you do on rectal exam if you are going to collect semen via electroejaculation?
palpate and massage glands
how can you assess the quality of the semen?
gross appearance
motility
morphology
is semen collected by electroejaculation evaluated for volume or concentration?
no
what is the normal color of semen?
milky white
what is wave motion influenced by?
sperm concentration
velocity
% progressively motile
is gross motility used to rate motility?
not anymore
what is the minimum threshold for individual motility?
30%
how many sperm cells should you count for sperm morphology?
at least 100 sperm cells
what is the minimum threshold for morphology?
70% normal spermatozoa
how are defects grouped?
where it affects: head, midpiece, or tail
how are sperm abnormalities classified?
compensable defects
noncompensable defects
what must a satisfactory potential breeder meet or exceed the minimum thresholds for?
scrotal circumference
sperm motility
sperm morphology
what makes a bull an unsatisfactory potential breeder?
below one or more thresholds or
has genetic faults or physical problems and is unlikely to every improve status
what are the big venereal diseases?
trichomoniasis
campylobacteriosis
what is the etiology of trichomoniasis?
Trichomonas foetus
what are the signs of trichomoniasis in bulls?
asymptomatic- no lesions
which bulls are more prone to infection with trichomoniasis?
more than 4 years old
what should you confirm positive culture of trichomoniasis with?
PCR
how can trichomoniasis be treated?
no approved effective treatment
cull infected bull and replace with known clean bull
cows may clear organism after 3 normal cycles
what is the vaccine for trichomoniasis?
trich guard vaccine
only effective in females
what causes campylobacteriosis?
Campylobacter fetus venerealis
what is the treatment for campylobacteriosis?
local antibiotic therapy
vaccination will cure a large percentage of bulls
what percentage of bulls may have unacceptable libido?
10-20%
how should young bulls be grouped?
together- social dominance
what does the bull to female ratio depend on?
age of bulls
length of breeding season
pasture/range conditions
estrus synchronization programs
what are the indications for a breeding soundness examination in a bull?
pre-purchase exam
pre-breeding exam
post-breeding problem
do you need to do a sperm count if the scrotal circumference is good?
no
what is the minimum scrotal circumference for a bull between 15 and 18 months?
31 cm
what can a yellow color to semen indicate?
urine contamination
what should you check for when grossly looking at semen?
hemorrhage
inflammatory exudate
what is individual motility?
estimate percentage of progressively motile sperm
is gross motility or individual motility preferred?
individual motility
what does computer assisted sperm analysis look at?
percentage of total motile sperm
percentage of progressively motile
path
velocity
what stains can be used for sperm morphology?
eosin nigrosin
williams stain
giemsa stain
how is sperm grouped when examining it for morphology?
percentage:
normal
head defects
midpiece defects
principal piece defects
what is a compensable defect?
can add more semen to overcome and fertilize
some sperm cannot travel well
who might benefit from a classification being deferred due to benefiting from being retested?
yearlings with poor morphology
heat stress, trauma
treatable disease
ejaculate could not be obtained
how do trichomoniasis and campylobacteriosis present in the cow herd?
early embryonic death
increased repeat breeders
occasional abortions or postbreeding pyometra
low overall percentage of herd pregnant
where does Trichomoniasis reside in a bull?
preputial crypts
what is the semen quality like with Trichomoniasis?
normal
how can you prevent Campylobacteriosis?
vaccinate all cows and bulls: 2 doses 4-6 weeks apart, annual booster
biosecurity
what bull to female ratio should be used for yearling bulls?
1:15-1:20
what bull to female ratio is generally safe?
1:25
