Breeding Soundness Exam Flashcards
what effect does high nutritional diets have during prepubertal period for male cows?
reduced the age of puberty and increased size and weight of testicles (we want them to hit puberty sooner so they can nut more for longer)
what effect does high nutritional diets have DURING puberty for male cows?
fat deposition around testes, lamanitis, abnormal bone and cartilage growth lameness, etc. AKA dont feed them too much you DINK
how do we decide to group bulls together?
depends on age, bull libido, fertility, environment (like size of pasture), feed and water availability
what is a bull:cow ratio and what is the number we want?
essentially it’s how many cows can one bull shag
1:20-1:30 is most common. the older the bull, the more ladies he can handle
when shopping for bulls, what are some things that help you decide which bull to buy?
can use expected progeny differences (EPDs)
certain breeds: hybrid vigour, breed traits
conformation
herd improvement vs terminal sires (a terminal sire is where no calves kept as replacement and all sold for meat)
ultimately it depends on the goals of your producer
what is an expected progeny difference (EPD)? what major categories are you looking at?
an evaluation of an animal’s genetic merit, essentially you compare bulls to their breed standards
calving: calving ease
growth: weaning or yearling weight, milk
carcass: weight, marbling, rib eye area, fat thickness
maternal: docility, milk
how to select for good birth weights based on EPDs?
normally for EPDs, we want a bigger number, but for birth weight, we want a small number because lower birth weights means less risk of dystocia
what do CED and CEM stand for and how do they differ?
CED: calving ease direct, takes into account the birth weight of the calf
CEM: calving ease of the mother (does not take into account calf birth rate)
for heifers, what EPD values do you want to select for when choosing your bull? How about for more mature cows?
for heifers: select for smaller birth weights (smaller numbers)
for mature: select for better carcass quality or bigger calves depending on what the producer wants
why do we do BSE’s yearly?
because 20% of bulls are subfertile and the greatest econominc loss is with subfertile bulls and delayed conception. Every time we delay conception you lose weaning weight!
80% of cows are bred by 2 or more bulls so the lower fertile bulls are compensating for the more fertile bulls
what are the 3 aspects of fertility?
good libido, physical soundness, good semen quality
how do you test a bull’s libido? what are the downsides to doing this?
serving capacity=number of matings a bull is willing and able to perform in a test situation
downsides: not accurate in yearlings (they are shy and get scared when older bulls around), not welfare friendly for the females
what are the 4 components of a breeding soundess exam?
physical exam
internal genitalia exam
external genitalia exam
semen evaluation
why is body condition score important during your BSE PE?
too fat=can’t breed, it’s too hard, omg poor horny fat bulls
too skinny=no energy to breed omg poor starving bulls
what BCS is ideal for bulls
3 or 4 out of 5
why is leg conformation important to evaluate?
cows with bad comformation get culled sooner
what general diseases do you want to look for on PE of bulls?
IBK, cancer eye, lumpy jaw, foot rot
how to treat foot rot/interdigital necrobacillosis
systemic abs and NSAIDs
what external genitalia structures do you need to examine?
scrotum, testes, epididimies, spermatic cord, penis, prepuce
when palpating the testicles, what are you feeling for?
are the testes freely moveable? are they equal in size and consistency? are the epididymes turgid and prominent?
scrotal dermatitis in bulls can be caused by
frost bite!
proper way to measure scrotal circumference?
hold the scrotal neck with one hand and then use a measuring tape with the other hand! It should be fairly snug, but not too snug!!
what is approx range of normal scrotal circumference in bulls?
for a 12 month old: the high 20s to low 30s range in cm
larger scrotal circumference is associated with
greater testicular volume=greater sperm production
earlier onset of puberty in offspring
for an internal genitalia exam what are we looking at?
vesicular glands, ampullae, inguinal rings
what should normal ampullae, seminal vesciles, and inguinal canal feel like on rectal palpation
ampullae: 10-15cm long and 5-8cm in diameter
vesciles: 8-15cm long, 3-5cm long
inguinal canal: should feel like a slit on either side, 15-20cm ventral to the pelvic brim and 5-15cm lateral of midline
what are 2 ways to do semen collection?
artificial vagina and electroejaculation
what are the 2 broad categories of a semen evaluation
motility and morphology
how do we evaluate semen motility (procedure)?
on a heated slide, put a drop of semen on the slide and look at 100x
OR can put a drop of semen on a slide and look at 250-500x mag and use a phase contrast microscope
hoe do you evaluate semen morphology?
on a heated slide, put a drop of semen and drop of eosin nigrosin stain to mix and smear, then use oil immersion at 1000-1250x magnification
describe the gross swirling semen motility scores and what they mean?
VG/very good: rapid dark swirls
G/good: slower dark swirls
F/fair: no swirls but individual cell motion
P/poor: little or no individual motion
how do you measure PROGRESSIVE motile sperm?
need a special microscope, BUT it’s the gold standard and is more accurate.
we want more than 30% progressively motile sperm
when evaluating semen morphology, what percent normal do we want?
more than 70% normal
detached heads (no tails) are associated with…
defective development OR bulls following sexual rest
upon doing a semen morpholohy examination, you find these. what are they and what does this indicate? Does this defect affect the sperm at all?
these are knobbed acrosomes
due to stress OR abnormal thermoregulation
these sperm cannot penetrate the zona pellucida of the egg
what is the most commonly missed morphology defect and what does it indicate?
nuclear vacuole defect
if present in large numbers=envonrmental issues, stress, thermoreguation, dexamethasone, toxins
a pyriform shaped sperm head indicates…
environmental heat stress
what does this morphology abnormality indicate?
this is a Dag Defect
it is heritable or diet related
common in danish kersey bull
what is this morphology abnormality indicate?
this is a cytoplasmic droplet
common in young bulls
proximal drops are worse than distal drops
what is this defect and what does it indicate?
a bent tail
caused by improper handling of semen sample like hypotonic solution such as staining or cold shock, so you should recollect the bull and get a new sample to look at
what is this defect and what does it indicate?
distal midpiece reflex
related to thermal insult of the testes
if a bull has vesiculitis, what will you see on semen evaluation?
WBCs and RBCs under the microscope and barely any sperm
what are the 4 “decisions” you can make at the end of a BSE?
satisfactory: meets the min requirements of motility and morphology, for scrotal circumference, and for PE
deferred: for younger bulls who need to be retested, or in mature bulls expected to make a recovery
questionable: give them time and re test them
unsatisfactory: not meeting minimum requirements
t or f: a satisfactory potential guarantees fertility
false!
transmission, clinical signs, and treatment/prevention of: trichomoniasis foetus
transmission: infected bull to a cow, back to a bull again via breeding
CS: early embryonic death, extended breeding seasons, and poor pregnancy rates
treatment/prevention: purchase virgin bulls who haven’t gotten infected via breeding an infected cow, testing and culling
a producer calls you to ask how he can test his bulls for trichomoniasis, you tell him…
test 3 times 1 week apart to get highest sensitivity
either a pooled PCR (cheaper but if it’s positive you have to go hunting) or a culture (cannot differentiate from other trichomoniasis)
what is the cause of vibrio? transmission? clinical signs? treatment prevention?
campylobacter fetus sp veneralis
transmission: survives in raw and processed bull semen. bulls are asymptomatic carriers. young bulls are resistant to the infection but older bulls become chronic carriers.
CS: vaginitis, cervicitis, irregular and delayed return to estrus, early embyronic death, abortion in late gestation
treatment: avoid contact with infected bulls and vaccine bulls
how can you test your herd for vibrio?
preputial smegma, vaginal mucus, culture sample
best option is PCR, most sensitive and specific
