Final Exam - Bovine Infertility

Question 1

what are 4 ways we can improve food animal reproduction?

Answer 1

1. work by appointment - plan calving, breeding, etc
2. work in-clinic!
3. utilize ultrasound!!!
4. good environmental stewardship

Question 2

what animals are you looking at for a dairy herd health visit?

Answer 2

looking at postpartum cows, anestrus cows, pregnancy checks, & repeat breeders

Question 3

how do you best palpate the reproductive tract of a cow?

Answer 3

must be good at moving the uterus to where you can palpate it!

flip the uterus to the ventral surface to check for early pregnancy & try not to grab the intracorneal ligament

Question 4

what will you do for a non-pregnant cow following a pregnancy check? what is your goal for progesterone levels?

Answer 4

estrus induction & AI

GnRH is given & a CIDR implant is used

CIDR implant is removed on day 7 - PGF2a is given to lyse the CL

60-66 hours later (day 7-day 10)

GnRH is given again & the animal is artificially inseminated

high progesterone at day 7!

Question 5

what does normal discharge of a postpartum cow look like?

Answer 5

normally red-brown, mucoid, & odorless!

Question 6

what should you feel by 3 weeks postpartum on rectal evaluation of a reproductive tract on a cow? why?

Answer 6

you should feel longitudinal striations in the uterus

the uterus expels tissues quickly but the endometrium needs time to heal & involute

Question 7

what is the most common cause for repeat breeders?

Answer 7

purulent vaginal discharge!!!!

Question 8

T/F: any purulent vaginal discharge is ABNORMAL

Answer 8

true

Question 9

what animals will you do a vaginal exam on? what do you need?

Answer 9

any repeat breeders

clean technique & a disposable speculum!

Question 10

what is post-estrus bleeding? is this abnormal?

Answer 10

spontaneous vaginal discharge 48 hours after estrus with a variable amount of blood

not abnormal!!! 60% of heifers & 40% of cows will do this!

Question 11

what happens to your income if 10% of your cows aren’t having calves?

Answer 11

you are losing 10% of your income!

Question 12

why do we need dairy cows to reproduce?

Answer 12

to replace cows

initiate & optimize milk production

Question 13

what are some examples of venereal diseases that can cause vaginitis in dairy cows?

Answer 13

IBR/IPV

trich

vibrio

idiopathic

Question 14

what is the lesion shown in this photo? does it affect the animal’s fertility? where are they observed?

Answer 14

mesonephric duct cysts - remnants of the male mesonephric tract!

no effect on fertility!!!

observed at the 4 & 8 o’clock position on the floor of the anterior vagina

Question 15

what is the lesion shown in this photo? does it affect the animal’s fertility?

Answer 15

double cervix - two cervixes that each connect to its own respective horn

cows can present later in life with this & still have had good fertility!

Question 16

what is the lesion shown in this photo? does it affect the animal’s fertility?

Answer 16

double external cervical os - cervical canal assumes the configuration of the letter Y

fertility can be normal

Question 17

what are 3 examples of congenital malformations that you may encounter in dairy cows?

Answer 17

1. mesonephric duct cysts
2. double cervix
3. double external cervical os

Question 18

what is the lesion shown in this photo? what animals are more commonly affected by it? how do you manage this animal’s reproductive abilities?

Answer 18

cervical ectropion - hypertrophy of the cervical folds that prolapse through the external os

common in bos indicus breeds

difficult to AI these gals - better off with a bull

Question 19

what is the lesion shown in this photo? what caused it? what are the sequelae of this?

Answer 19

cervical adhesion - result of trauma :/

cervical adhesions can cause obstruction & mucometra

Question 20

cervical discharge in cows is usually caused by what? how do you treat it?

Answer 20

endometritis - will see pus + mucus

very common issue - treat them with prostaglandin

Question 21

what should be considered when looking at pregnancy rates & postpartum endometritis in cows?

Answer 21

pregnancy rates will increase with more days postpartum (70% rate by 120 days postpartum vs. 30% at 30 days postpartum)

bacterial prevalence decreases with more days postpartum

need to give them more time before breeding them again to help prevent this!

Question 22

what is a good example of the dose resistance balance of postpartum endometritis?

Answer 22

dose - hygiene, conformation, assisted calvings, & RP/metritis

resistance - nutrition

Question 23

how is postpartum endometritis treated?

Answer 23

multiple short cycles to allow the uterus to evacuate bacteria & return to normal - use of lutalyse!!!

used to do uterine infusions - not so much anymore

Question 24

what should you do when managing a repeat breeder cow without endometritis?

Answer 24

induce estrus in 7 days - co-synch protocol & CIDR

timed artificial insemination

Question 25

T/F: beef herd health visits for reproduction are less intensive than dairy herds

Answer 25

true

Question 26

what is included when doing a beef herd health check for reproduction?

Answer 26

mostly pregnancy checks & breeding soundness exams!!

Question 27

how are pregnancy checks done in beef herds?

Answer 27

ultrasound is recommended - allows for accuracy within 10 days

many people are proficient in rectal palpation though - can recognize pregnancy by 1 month

Question 28

how is record analysis used for monitoring beef cattle herd health?

Answer 28

highest rates in 1st 21 days = good fertility

highest rates in 3rd 21d period with peak rates 40% = energy/nutritional mgmt needed

rates in first 21d at 40%, then decreasing with another 21d period = infectious

Question 29

T/F: BSE should include trichomoniasis testing

Answer 29

TRUE!!!!

Question 30

how are bulls verified as virgins?

Answer 30

can be certified as virgins by a veterinarian between 18-30 months of age in TX - producer must have the facilities to keep the bull away from all of the other animals to ensure it is a virgin

Question 31

what are prostaglandins used for?

Answer 31

used to get rid of a CL - estrumate is very potent & cleared quickly

Question 32

how is calving on appointment managed?

Answer 32

280+ days & good colostrum with 80% born between 30-46 hours - best just to give PGF2a & dexamethasone

7-9 months, PGF and/or dexamethasone

Question 33

how many sperm should you aim for in virgin heifers?

Answer 33

2 million sperm

Question 34

how is superovulation done?

Answer 34

high doses of FSH are given BID for 4 days to allow for many follicles to ovulate

Question 35

how is embryo transfer done following superovulation?

Answer 35

embryos are collected from the uterus & a 0.25 mL straw is filled with them (bubbles surround embryo & keep it in fluid)

cooling is done to room temp & a cryoprotectant is added - then cooled to -7°C

straw is then squeezed with forceps to form crystals - cooled to -35°C - then plunged into liquid nitrogen

embryos are then thawed with a 4 step dilution of cryoprotectant & then are transferred to the intended cow after the 4th step (lately, thawed in a 1 step method - no microscope needed, water bath, & straw is shaken)

Question 36

does semen sexing work? how?

Answer 36

yup - 95% efficient

laser & magnet are able to deflect X & Y sperm into different vials

Question 37

what is the importance of monitoring the environment for toxins in regards to cattle reproduction?

Answer 37

oil spills in texas can harm bovine reproduction!

mutagens can harm reproduction through harming DNA

endocrine disruptors harm reproduction by competing with reproductive hormones - phytotoxins, mycotoxins, industrial toxins, & agricultural toxins (pesticides)

Question 38

what is a comet assay? what is it used for?

Answer 38

sperm cells are mixed with agar, DNA is released from packing, & DNA is fluorescein stained

detects if benzene is affecting fertility in cattle (plastics, oil, etc)

if comet tails are seen = fragmented/damaged DNA is present

Question 39

are environmental estrogens detected by immunogenic tests?

Answer 39

nope - bioassay test is able to detect estrogenic activity

Question 40

what is the mechanism of endocrine disruption from environmental estrogens? how do we evaluate for this?

Answer 40

binds to intracellular receptor - transcription of DNA - production of protein - function is carried out

ELISA (specific) assay!

Question 41

what test is used for hypogonadotropic hypogonadism? why?

Answer 41

GnRH response testing - LH release is caused by GnRH

testosterone release corresponds to LH release, FSH, & circulating steroids