Theriogenology Flashcards

Terms Definitions
Name four reasons for raising sheep.
What are 2 types of Sheep management systems?
What are the 5 Categories of Sheep Breeds?
1. Meat = Callipyge (generally dark faced breeds)2. Wool (Ex. Lincoln)3. Dual Purpose = meat and wool (Dorset is the best dual purpose breed)4. Synthetic/Cross breeds5. Reproductive breeds = wants ewes that can have large litters (want to select ewes that can have twins or triplets)
What is flushing?
-The act of increasing nutrient uptake of ewe 20-30%, 2-3 weeks prior to breeding -This is especially important for thin ewes, to get them into breeding condition (fat ewes don’t respond well to flushing and are poor breeders)
When should you flush a ram?
8 Weeks prior to breeding.
What are 3 ways to preg check a ewe?
-Non-return to heat at 16-17 days-Transrectal U/S at 20+ days-Abdominal U/S at 35 days ***U/S is the only practical way to preg check ewes***
Describe proper ewe management during pregnancy.
-Prevent pregnancy toxemia by providing proper nutrition-Exercise-De-worm-Vaccinate-Medicate-Shearing (to be coordinated w/ the annual shearing), tagging, crutching -Shearing allows easy access to the nipple for the lamb and causes the ewe to get cold and hopefully persuade her to lamb inside
When does puberty occur in a sheep?
5-15 months.When the lamb attains greater than 60% of his adult body weight.
What are some factors that affect the onset of puberty?
-Time of lambing -Lambs born in June will probably skip their first cycle -Lambs born in Jan. and fed well will probably have their first cycle in fall-Nutrition-Breed (Finn> Suffolk> Rambouillet- tend to have late sexual maturiy)
How much time passes between ovulations in a sheep?
16-17 days
How long is a ewe actually in heat during one ovulation?
10-40 hours.Average = 36 hours
When can you AI a ewe?
18-24 hours post standing estrous
List some sexual behaviors in Sheep.
When do sheep tend to breed?
Short days
Name some breeds that breed put of season.
When you should give up trying to breed a ewe.
When the cops show up.Don't try to breed a ewe more than 3 times
What is the gestation period for a ewe?
140-155 daysAverage = 148
What are some first signs of parturition in a ewe?
Restlessnessdecreased appetitemotheringswelling of vulvacolostrumsdecreased body temp.
in sheep, how long do first stage uterine contractions last?
2-8 hours
What happens during the second stage of parturition in a ewe?
Cervix is stretched and oxytocin is released. Abdominal pressing can last from 20 minutes to 2 hours.
In what age range are ewes most prolific?
3-6 years
how long is the post partum period for a ewe? (how long before she can have a productive estrous cycle?)
30 days
How should you supplement the nutrition of an expecting ewe?
50% increase in nutrients over the last third of gestation.
When should you wean a lamb?
8 weeks
What are the seven steps to synchronizing estous in sheep?
1. Give progesterone in spring and fall -Spring = need to give FSH in addition to progesterone -Fall = only need to give progesterone -Synchronize NO more than 5 ewes/day/ram2. Give prostaglandin during breeding season -Prostaglandin ONLY works when ewe is cycling3. Ram effect -The rams pheromones and vocalization can help to synchronize the ewes4. Daylight effect5. Superovulation/increased number births6. Steroid hormone immunization -Steroid inhibits the negative feedback so more FSH can be released -This increasing lambing % by 20-30%7. Synchromate B (has been pulled off market)
When is the earliest you can induce parturition in sheep?
141-142 days of gestation
What two drugs can be used to induce parturition in sheep and when will they have an effect?
Dexamethasone - lamb will be born within 72hEstrogen - lamb will be born wihin 24h
What are the 3 major causes of abortions in sheep?What are some other agents that cause abortions?
1. Vibrio (Campylobacter fetus)2. Toxoplasmosis3. ChlamydiaOthers include:-Border disease (hairy shaker lamb)-BVD-Salmonella typhimurium-Listeria monocytogenes-Lepto-Bluetongue virus-Coxiella burnetti (i.e. Q fever)-Sarcocystis
Which, of the major abortion causes in sheep, can cause early abortions?
What are the gross lesions associated with Vibrio abortions in sheep?
-Placentitis w/ edema-Necrosis of cotyledons-Intrauterine death-SQ edema and fluid-Necrotic liver foci (rare, only occurs in 40%)
What are the gross lesions associated with Toxo abortions in sheep?
-Cotyledons have gray/white foci (1-3mm in size)
What are the gross lesions associated with Chlamydia abortions in sheep?
-Chorionitis w/ elementary bodies (seen on impression smears)
How do you control Vibrio abortions in sheep?
-Hygiene-Vaccine-Mass medication
How do you control Toxoabortions in sheep?
-Control young cat population on farm (cats are #1 transmitter of oocyts)-Rumensin (antibiotic)
How do you control Chlamydia abortions in sheep?
What are some clinical signs of Vibrio abortions in sheep?
-Late pregnancy abortions-Stillbirths-Weak lambs-Metritis-Peritonitis
What are some clinical signs of Toxo abortions in sheep?
Early pregnancy:-EED-Fetal death-MummiesLate pregnancy:-Abortion-Perinatal lamb loss
What are some clinical signs of Chlamydia abortions in sheep?
-Late abortions-Still births-Weak lambs-Fetal mummification-Congenital infections abort first pregnancy
How do you treat sheep abortions?
1. Diagnosis is the #1 priority (submit sample for histopathology: placenta, fetus, blood)2. Tetracycline3. Isolation4. Sanitation5. Monensin6. Bovatec7. Prevent zoonoses (Toxo and Q-fever)
How do you prevent sheep abortions?
1. Vaccinate for vibrio and EAE2. Medicate w/ chlorotetracycline for vibrio and EAE3. Cat control for Toxo4. Med w/ monensin and bovatec for Toxo
What are some obstetric rules to live by?
1. Be clean2. Be gentle3. Use LOTS of lubrication4. Check for cervical dilation (ringwomb = syndrome where ewes don’t dilate)5. Double check presentation6. Size of pelvis to size of lamb7. C-section = $, future reproduction, lamb and ewe survivablility
What are some advantages of early detection of dystocia in sheep?
1. Increase # of lambs born2. Decrease ewe mortality3. Allow intervention
How do you deal with sheep dystocia?
-Intervene when there has been 1-1 ½ hrs. of no progress-Intervene if there is malposition (i.e. unilateral/bilateral shoulder flexion or breech)-Give an epidural of lidocaine to help alleviate straining-Lubricate, use good hygiene, give antibiotics, and vaccinate (tetanus antitoxin)-Treat ringwomb w/ c-section, cervical incision, manual dilation, estrogens-Any ewe that has had dystocia should be culled **Check for multiple lambs
What are some risk factors for vaginal prolapse in sheep?
-multiple ewes (?? multiple lambs?)-Excess estrogen-Pushing, crowding at feed bunk
Do you want to stitch a ewe's prolapsed vagina high and tight or low and away?
High and Tight
What dietary changes can be made to prevent a sheep from getting a prolapsed vagina?
Take away hay and feed corn and oats because hay takes up too much room in the rumen.
What is the Tx for a sheep vaginal prolapse?
-Retainer-Buhner stitch-Want to place vagina high and tight
What are some characteristics of a uterine prolapse?
-Seen post lambing due to difficult birth or hypocalcemia-Different from vaginal prolapse b/c with uterine prolapse you can see the cotyledons -More of an emergency than vaginal prolapse
What is the Tx for a uterine prolapse?
-Clean, replace, suture, systemic antibiotics
What are some problems that can cause fertility problems in rams?
Pizzle rotScrotal mangeScrotal AbscessesEpididymitis
What is the etiologic agent for Pizzle Rot?
What is the etiologic agent for Scrotal Mange?
Chorioptes bovis
What is the etiologic agent for Scrotal abscesses?
-Actinomyces pyogenes
What is the etiologic agent for Epididymitis?
-Brucella ovis -Causes spermatic granuloma of epididymal tubules-Actinobacillus seminis -Severe, acute, painful -Causes epididymitis in peripuberal ram lambs
What is the Tx for pizzle rot?
-Clean-Furacin ointment-Ammonium chloride (1 gram TID for several days)
What is the Tx for Scrotal Mange?
What is the Tx for scrotal abscesses?
What is the Tx for epididymitis?
-DO NOT VACCINATE-Test and cull
How does the estrus cycle in goats differ from sheep?
-More strictly limited to fall than sheep-21 day cycle-12-36 hrs. of estrus-AI after 12-24 hrs after onset of estrus-Doe will be restless, vocal, wag tail, swollen vulva, and have decreased milk production while in estrous
What is the gestation period for a goat?
140-155 days (median 2-3 days longer than ewe)
How can you, or more importantly, how can you not diagnose pregnancy in a goat?
-Increased progesterone during late gestation CAN NOT diagnose pregnancy-Look for soften cervical (d. 30) or cervix out of reach (d. 50)-Udder is NOT dependable for diagnosis of pregnancy
WHat are some causes of doe infertility?
-Endometritis-Pyometra-Cystic Follicles-Hydrometra (pseudopregnancy) -Treat w/ PGF2-alpha or surgery
What are some causes of abortions in goats?
-Toxo-Chlamydia-Salmonella-Brucellosis melitensis (may not be a cause in the US)-Listeria-Lepto (greater importance in does than ewes, they will abort at the time of infection)-Angora goats are habitual aborters due to their adrenal cortical depletion
What are some Causes of Buck Infertility?
-Spermatic granuloma (associate w/ polled gene) -Occurs between the head of epididymis and testes
What are some characteristics of AI in goats/sheep?
-Can use fresh or frozen semen-50-350 million live sperm per insemination-Can AI intrauterine or intracerival-Can use a laparoscope-AI 12-24 hours after start of estrous-60-70% first service conception rates
What are some purposes for llamas?
-Llama’s are guard animals (used w/ sheep to protect them from dogs, coyotes)-Pack animals-Fiber-Meat
What is special about a llama's testicles?
Located in the perineal region.
What are some characteristics of llama semen?
-Highly viscous-Milky white color-Slow motility (no mass motility as seen w/ ram sperm)-> 50% normal/desirable
What are some characteristics of llama penises?
-Penis is fibroelastic w/ sigmoid flexure-Adhesions present between body of penis and sheath in prepuberal animals-Urinate backwards between legs-Corkscrew appendage at tip used to dilate cervix and enter uterus during breeding-Stimulation – protractor penis muscle directs forward
What are some characteristics of llama estrus cycles?
-Periods of long sexual receptivity (36 days) and short periods of non-receptivity (48 hrs.)-Rhythmic increase and decrease due to follicle maturation and atresiaCL Function:-Peaks 9 days post mating-Maintains pregnancy-Luteal diameter and plasma progesterone highly correlatedOvulation:-Increase serum LH 15 minutes after onset of copulation (i.e. induced ovulators) -26 hrs. after natural mating they ovulate-Can induce ovulation w/ GnRH-New follicles develop between 12-16 days
What is the gestation period for a llama?
-335-365 days (avg. 345)
In what part of the uterus do most llama pregnancies happen?
Left horn (90-95%)
How do you diagnose pregnancy in llamas?
-Sexual behavior/Lack of estrous-Ballotment/External palpation-Rectal palpation-P4 levels >2ng/ml after day 18 indicates active CL and pregnancy-Ultrasound at 15 days (transrectal) and 50 days (transabdominal)**Diffuse epitheliochorial placenta**
What are some reasons for llama fetal deaths?
-High incidence of early embryonic death in the first 30 -90 days (decreases after 30)-Rebreeding too soon after parturition-Inbreeding-Uterine infection and pathology-Old age-Stress
Describe the stages to llama parturition.
Stage I = Preparatory (1-6 hrs.)-Stage II = Fetal expulsion (<60 minutes)-Stage III = Placental expulsion (4-6 hrs.)
When does ovarian activity resume after parturtion in a llama?
-Ovarian activity resumes 3 days postpartum -May breed at this time but they do not recommend till after day 15-20 days
How much colostrum does a cria need?
4-10% of body weight in first 10 to 12 hours.
What are some congential defects that lead to infertility in llamas?
-Gonadal aplasia and hypoplasia-Persistent hymen-Uterus unicornis-Double cervix and intersex (hermaphrodites)-Segmental aplasia
What are some acquired problems that lead to infertility in llamas?
-Metritis/Endometritis (generally caused by Strep)-Endometrial cysts = can determine via ultrasound-Cystic ovaries = variable response to GnRH or HCG
How do you diagnose infertility in llamas?
-History-Rectal-Ultrasound-Speculum-Culture-Biopsy-Hormone analysis
Name some equine ovarian structures.
-Follicle-Ovulation Fossa-Corpora Hemorrhagica-CL-Oviduct (infundibulum, isthmus, ampulla, oviductal papilla, uterotubal junction – which is the sperm reservoir)
What are the 3 physical barriers to contamniation of the equine uterus?
1.Vulva2. Vestibule3. Cervix
What are some congenital and acquired defects that cause infertility in mares?
CONGENITAL DEFECTS:-Persistent hymen-Tubular agenesis of cervix, uterus, oviductACQUIRED DEFECTS:-3rd degree perineal laceration-Rectovaginal fistula
What are some guidelines to performing an exam of the repro tract of a mare?
Restraint: put animal is the stocksProtective Wear: plastic palpation sleeveLubricatin: can’t ever get enough lubeManure removal: remove manure first before trying to find landmarks – cup hand dorsally to try and prevent rectal tears (if you do tear – better to tear dorsally than ventrally)Anatomic Orientation: Brim of pelvis, cervix, uterus, ovary
What are the components of taking a history for a BSE for a mare?
1. Age2. Parity3. # Foals4. Last foal date5. Stallion fertility/management/number6. Method of service (live, cooled, frozen)7. Dystocias8. EED = Early Embryonic Death9. Abortions/Stillbirths = what stage in pregnancy did they occur10. Endometritis/postbreeding11. Urine pooling/caslicks12. Twins = “Once a twinner always a twinner”
What are the components of a Vulvular Conformation Assessment in a mare?
-Look at vulva, vestibule, cervix
What are the components of a Transrectal Palpation in a mare?
-Check for: -Cervical tone -Uterine symmetry -Pregnancy -Ovarian symmetry -Ovulation fossa -Paraovarian cysts
What are the components of a Endometrial Cytology in a mare?
-Looking for active inflammation-Can diff quick finding and get immediate results-May see PMNs, fungal hypae, yeast, bacteria-Should NORMALLY see epithelial cells and mucus
What are the components of a Biopsy in a mare?
-GRADE I: -80% live foal rate -Glandular density -Tall columnar epithelium -Tortuous glands-GRADE II A: -Endometrial edema -Potentially reversible -Low glandular density -Dilated lymphatics -Cuboidal epithelium-GRADE III: -Glandular nesting -Fibrotic rings -<10% probability of foaling
What are the components of a Hysterocscopy in a mare?
-May see oviductal papilla, adhesions, and will allow for proper semen deposition
What are some benefits of doing cytology on the equine uterus?
-Rapid results-Can differentiate PMNs, macrophages, yeast, fungi, bacteria
What are the components of the male reproductive tract?
-Vesicular glands (seminal vesicles are unique to the horse)-Large ampullae-Bilobed prostate-Bulbourethral glands
List some potential venereal pathogens that may be transmitted in semen?
Bacterial:-Klebsiella-Pseudomonas aerugenosa-Taylorella equigenetialis (CEM)Viral:-EVA-Equine Coital Exanthema (EHV-3)Protozoal:-Trypanosoma equiperdum
Summarize minimal criteria that a stallion should meet to be classified as a satisfactory prospective breeder
-Free of undesirable, potentially heritable defects, behavioral disorders, or transmissible diseases-Posses no physical trait that would interfere w/ mating ability, semen quality, sperm output -Ejaculate minimum of 1x109 pm (billion), morphologically normal sperm in the 2nd of 2 ejaculates 1 hr. apart after 1 week of sexual rest
Describe an Assisted Vaginal Delivery (AVD).
-Mare is awake and minor assistance needed to deliver an intact foal-Standing is better than recumbent b/c the weight of the fetus in uterus helps to realign stuff-Xylazine and Butorphenol will put the front end to sleep and not the back end -too much of the drug and the mare can lose control of back end
Describe a Controlled Vaginal Delivery (CVD).
-Mare is anesthetized and clinician is in complete control of vaginal delvery-Use short term anesthesia-Elevate hind quarters => decreases uterine contractions and gets weight of abdominal contents off the fetus
Describe a Fetotomy.
-Fetus is dead and cut is made to deliver vaginally -very poor prognosis for future reproductive function in the mare if more than one cut is made
Describe a Cesearean Section.
-Mare is anesthetized and fetus is removed through an incision in the uterus -mares reproductive future is more positive than w/ fetotomy
Describe the more common obstetrical procedures used to correct dystocia in the mare by mutation and traction
Mutation: manipulation of fetus to return it to normal presentation, position and postureRepulsion: forced movement of fetus from pelvis to abdomen -Can use: -Clenbuterol = smooth muscle relaxant -Isoxuprine = muscle relaxant -Buscopan = smooth muscle relaxant
What are some common ways a foal can be malpositioned?
Retention of forelimb (carpal flexion)Retention of elbow on pelvic brim (very common)Lateral/Ventral deviation of head and neckTrue breech (transverse ventral presentation – back of fetus or 4 feet on exam)
Define Fetal presentation.
relationship of spinal axis of fetus to that of dam
Define Fetal position.
relationship of dorsum of fetus to the quadrants of maternal pelvis
Define Fetal posture.
relationship of extremities (head and front limbs should be extended) **most common abnormality
How do you treat a mare's retained placenta?
-Systemic antibiotics -Penicillin and Gentacin-NSAIDS -Flunixin, Ketofen, Butorphenol??? (phenylbutazone)-Oxytocin-Uterine Lavage
How do you treat a Uterine Prolapse in a mare?
-Control straining w/ epidural-Coat uterus w/ Vaseline-Cover w/ plastic bag-Elevate uterus to level of pelvis
How do you treat an invagination of uterine horn in a mare.
-Manual removal of placenta-Transect portion of placenta-Uterine lavage
How do you treat a Uterine rupture in a mare?
-Keep mare quiet-NSAIDS-Naloxone HCL (opioid antagonist ??)
What are the components of the mare's uterine defense mechanisms?
1. Physical barriers (vulva, vestibule, cervix)2. Opsonization of bacteria by PMN’s -Estrogen: increase in PMN function -Progesteron: decrease in PMN function -Ab’s and compliment -Resistant mares have higher levels of compliment3. Physical clearance -Cervical relaxation -Cervix relaxes and peak uterine contraction -Uterine position -Uterine contractions -Lymphatic clearance
Is a positive endometrial culture definitive for a diagnosis of endometritis?
What are the most common locations for genital infections in the mare?
List the most common organisms associated w/ endometritis in the mare
Bacterial:-Beta-hemolytic strep zooepidemicus-E. coli/enterobacter-Pseudomonas-KlebsiellaYeast/Fungal:-Candida albicans-AspergillusContagious Equine Metriris (CEM):-Taylorella equingenitialis
What is the average gestation time for a mare?
320-326 days
What is the seasonal influence on gestation?
Jan – Mar the gestation is 5-10 days longer
What are the nutrition requirements for a pregnant mare?
-Want mares BCS to be 6-7-From time of conception to 8 months of pregnancy have the mare on maintanence-9-11 months of gestation: 1.1-1.2 x’s maintenance (60-65% of fetal growth is occurring during those months)-Should be a forage based diet (alfalfa/grass) -Ca:P ration 1:1 (.2% and .3%) -Se, Cu, Zn, I, Mn
What are some health care considerations that should be made for a pregnant mare?
-EHV-1: vaccinate at 5,7,9 months-EWT: vaccinate 1 month prior to due date-WNV: vaccinate 1 month prior to due date-Deworm q. 60 days for tapeworms -Give ivermectin day of foaling b/c strongyloides westeri larvae can be in milk (encysted larvae are resistant => stress of lactation => uncyst => pass in milk => intessusseption in foal
What are some changes to the mammary glands that predict parturition in the mare?
Colostrum > 60 g/L-Ca, at 200 ppm 48 hrs. prior to parturition-Ca 300-500 ppm 24 hrs. prior to parturition
Describe the progression of events in the three stages of labor
STAGE 1: PREPARATORY:-30 minutes to 4 hrs.-Fetal rotationSTAGE 2: DELIVERY:-20-30 minutesSTAGE 3: EXPULSION OF PLACENTA:-30 minutes to 3 hrs.-If mare hasn’t passed placenta by 2hrs. intervene and give oxytocin
Outline the methods for inducing delivery in mare
Requirements for inducing ovulation:-335 days of gestation-Mammary gland development-Relaxation of pelvic ligaments-Colostrum-Milk Ca> 300ppmInducing delivery:-Oxytocin (drug of choice) -causes milk let down, myometrial contractions and uterine involution and expulsion of retained placenta-PGF2alpha
Describe the physiologic changes during the transition from anestrus to ovulation
-Anestrus: -Low GnRH, FSH, LH, E2, P4-During Transition: -↑ GnRH => ↑ FSH -LH synthesis lags behind FSH synthesis -Multiple follicular waves occur 14 days apart -After 3 waves (42 days) the mare is transitioned and ready to ovulate -Mare is ready to ovulate when there is an INCREASE in estrogen 17B => LH release => Ovulation
List guidelines for an artificial lighting program
-Photoperiod controls cyclicity-16 hrs. of daylength is required to advance cyclicity-45-60 days to induce 1st ovulation-Add day length to the pm-Incremental increases is NOT necessary
Discuss the rationale for progestogens in the transition period of mares
-To shorten the duration of transition-Transitional mares have insufficient LH stores to induce ovulation-Progestens inhibit LH release resulting in storage of LH in pituitary gland (does not affect FSH so mare can still get follicular growth-Treat for 10-14 days w/ altrenogesto rP4 during mid to late transition-Requires a follicle 25mm or greater in size
Give the length of the embryonic, fetal, and neonatal periods in horse
Embryonic = conception until d. 40Fetal = d. 40 until parturitionNeonatal = birth until d. 28
What are the maternal signs of embryonic loss in the mare?
-Low P4-Large cysts-Endometrial fibrosis can prevent proper migration of fetus-Post-mating endometritis -PGF2alpha produced and causes lysis of CL
What are some changes in the uterine environment that are signs of embryonic loss?
-Endometritis (most common)-Periglandular fibrosis-Endometrial cysts
Discuss management options for embryonic death in mare
-Ultrasound monitoring q. 1-3 days-P4 supplement (not sure if it works but won’t hurt anything)-If no fetal heart beat by d. 30 must manually crush the vesicle -give PGF2alpha to lyse the CL and end pregnancy and then do a uterine lavage
List the causes of placental dysfunction in mare
-Uterine fibrosis-Hydroallantois-Placental edema-Infectious diseases
List the more common infectious causes of abortion in mare
1. EHV-1 -prior history of URT infection in young stock -Fetal hepatic intranuclear inclusions is pathognomotic2. Mycotic placentitis -Aspergillus3. Bacterial placentitis ASCENDING BACTERIA -Beta hemolytic Strep Zooepidemicus (#1 cause) -E.coli and pseudomonas are other causes HEMATOGENOUS BACTERIA -EVA -Lepto (in the fetus) - Nocardia
Design a thorough diagnostic approach to an abortion problem on a broodmare farm
-Submit specimens for histopathology (aborted fetus and placenta)-Post-mortem exam: -Intact stomach and contents -Liver -Kidney -Spleen -Adrenals -Placenta -Uterine fluid – run CS and cytology-Serology of fetus and am
When do you Dx a twin foal?
day 14-16
Describe Conceptus mobility throughout uterus.
-Embryo is highly motile and moves through out the all 3 areas of uterus (the 2 horns and body) -peak motility d. 11-12 (the motility is associated w/ uterine contractions) -the estrogens produced by the early embryo contribute to contraction and motility of embryo -the embryo must migrates in at least 2/3 of the segments for maternal recognition -restriction to the 1/3 of the uterus may cause the mare to return to estrus on day 14 -large, cystic follicles can also restrict migration and lead to problems w/ recognition
When does the foal embryo enter the uterus?
day 5-6
when and how does embryonic vessicle fixation occur?
-Occurs d. 14-16 and the vesicle localizes at the base of the horn-Need both P4 and E2 (produced by embryo) for this to occur-Will see: increased vesicle size, increased muscular contractility (thickening of the dorsal uterine wall)-If endometrial edema is noted that is not good
How does maternal recognition of the foal occur. what happens if the mother does not recognize the embryo?
-The embryo’s migration is what helps the mare to recognize the pregnanct -if the mare has not recognized the embryo by day 14 then PGF2alpha is released and the CL is lysed
Discuss emdometrial cup formation.
-Formed in the chorionic girdle of trophoblasts-Formed d. 25-38 and lasts until d. 150-Cup releases of eCG and PMSG -eCG has FSH and LH like activity to cause formation of accessory CL’s -accessory CL’s are formed by d. 35-40 and last until d. 150-200
Discuss Supplemental CL formation.
-Primary CL last until d. 25-30 and the accessory CL pick up the need to produce progesterone around d. 30-40-D. 40-50 the progesterone comes from the fetus (called 5alpha-pregnanes)
Discuss Placentation in the mare.
-Fixed by d. 16-True placentation = occurs gradually-Trophoblastic microvilli = d. 25-Endometrial cups = d. 35 (the cup will eventually make eCG and will persist even if pregnancy is lost)-Microoctyledons = d. 45-Microplacentomes = d. 150
Where does P4 come from during equine pregnancy?
-Initially comes from primary and accessory CL’s-D. 40-50 comes from fetal progesterone
Where does E2 come from during equine pregnancy?
-Mare-Placental-Fetal gonads -d. 150 dominant source is fetal gonads and placenta
Where does eCG come from during equine pregnancy?
-Endometrial cup
When can you likely diagnose an equine pregnancy transrectally?
Day 15
When can you likely diagnose an equine pregnancy via Trans-abdominal US?
day 150 - 210
What does estrogen sulfate have to do with equine pregnancy?
-High levels of E2 produced by the conceptus as early as D. 12-D. 60-100 estrogen sulfate> estrogen-Total E2/P4 assays are useful in assessing fetal viability
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