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62 Cards in this Set

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  • Back
What do ovaries produce and what are its endocrine function?
Ovaries produce eggs endocrinology: estrogen and progesterone
What is included in the tubular portion of the mares reproduction tract (6)?
What is the broad ligament?
two lateral ligaments supporting the uterus and ovaries and composed of two layers of peritoneum (membrane).
What type of estrous cycle does a horse have?
Seasonally polyestrous
Describe seasonal polyestrous.
-multiple estrous/ovulatory cycles
-March/April through Sept/Oct
-June to August is greatest reproductive activity
-has transitional phases
What is sexual photoreceptivity?
-response to increasing daylight
-GnRH from stimulated hypothalamus causes release of FSH and LH from anterior pituitary
-long day breeder
What does puberty depend on? (6)
What is the difference between sexual maturity and puberty?
Puberty is the start of estrous cycles and fertility, where-as maturity is the ability to raise a healthy baby (usually after puberty).
When does puberty usually occur in mares?
12-18 months of age
What are the stages of the Estrous cycle?(5)
-proestrus (1-3)
-estrus (5-7 days)
-diestrus (14-16 days)
-anaestrus (5-7 months)
What occurs during proestrus?
-preparation for release of oocytes
-increased FSH, estrogen, and follicle size.
-decreased LH
What occurs during estrus?
*Note spelling; not the same as Estrous!!
-sexual receptivity to stallion
-ovulation 24-48 hrs before end of this cycle
-increased estrogen
-decreased progesterone
What occurs during metestrus?
-development of CL (corpus luteum)
-increased progesterone
-decreased estrogen
What is approximate rupture size of follicle?
What do luteal cells produce and where are they formed?
They produce progesterone and line corpus luteum.
What occurs during diestrus?
-period of highest progesterone production
-late in diestrus, prostaglandins cause CL to regress
+decreased progesterone, increased FSH, new cycle begins
What is anaestrus?
Period between breeding seasons.
What are some ways to test what cycle a mare is in?
-rectal exam
-ultrasound exams
-vaginal speculum exam
What is teasing?
-the cornerstone of a successful breeding program
-exposing mare to sexual advances of stallion and recording response
What are behavioral signs of diestrus?
Active antagonism:
-pinned ears
-attempt to flee
What are the signs of proestrus and metestrus?
Not angry, more receptive but not wanting to breed yet.
What are the signs of estrus?
-approaches male
How does the uterine tone change during estrus?
Tone becomes more flacid (dough-like), increased adema (water build-up).
How do the ovaries change during estrus through rectal and ultrasound methods?
-follicle size increases
-follicles firm up
-24-48 hrs before end of estrus, follicle softens, deforms, and ovulates.
What cervical changes can be seen using a vaginal speculum exam?
diestrus: no fluid, solid tone
estrus: dough-like tone, increased edema, pink, and "melted onto vaginal floor".
Where does fertilization take place? How long does egg stay here?
In oviduct. Stays for 3-5 days before moving into uterine horn.
When does implantation occur after fertilization?
Around day 16
What is the life expectancy of eggs and sperm?
egg: 12 hours
sperm: 3-5 days
What are the common types of breeding methods?
-pasture breeding
-hand breeding (with handler)
-artificial insemination
How long are horses pregnant for?
340 Days on average
When can you test for pregnancy through rectal exams? U/S? Laboratory testing?
-40 days
-10 days *prefer 16 incase of twins
-90 to 100 days using estrone sulfate (not used often).
When hand breeding, what can often be used for safety of horses and handler?
What are the three stages of pregnancy?
1) period of ovum/blastula
2) period of organogenesis
3) period of fetal growth
What happens and how long during the period of ovum/blastula stage of pregnancy?
Increase in cell numbers during days 1-12
What happens (and how long)during the period of organogenesis?
Development of organ systems from days 12-60.
What happens and how long is the period of fetal growth in pregancy?
Final details, maturation, and growth through days 60-340.
What 4 simple things can you do for the mare to help with pregancy and health of foal?
-good nutrition
What are the functions of the placenta?
-waste management
-enzymes and hormones
What are the parts of the fetal placenta?
What is the endometrium?
The maternal placenta
What are the different types of placenta in horses?
-fetal placenta
-maternal placenta
-diffuse placenta
When should all vaccines be given to a mare during pregnancy and why?
Around 10 months of pregnancy to increase antibody production in colostrum.
What is the endometrium?
The maternal placenta
What are the different types of placenta in horses?
-fetal placenta
-maternal placenta
-diffuse placenta
When should all vaccines be given to a mare during pregnancy and why?
Around 10 months of pregnancy to increase antibody production in colostrum.
What are 4 signs of parturition? How long before birth do these signs appear?
-udder development: 2-6 weeks
-croup/perineal relaxation: 7-10 days
-udder distention, colostrum: 2-7 days
-waxing: 6-48 hours
What is waxing?
Colostrum drips from udders and solidifies into a waxy substance
Describe the first stage of parturition.
-active uterine muscle contraction
-1-4 hours long
-signs of abdominal discomfort
Describe the second stage of parturition.
-entrance of fetus into birth canal
-rupture of chorio-allantois (breaking water)
-labor (abdominal contractions)
-expulsion of fetus
-generally less than 30 minutes
Describe the third stage of parturition.
-Expulsion of fetal membranes
+within 4 hours
+retained placenta is life threatening
-uterine involution (shrinking to normal size)
What is abnormal birthing (positions) called?
When does estrous begin after parturition?
What is this called?
-11 days later
-foal heat
What drug can be administered to initiate/continue contractions?
What exams are performed before breeding a mare?
-in estrus exam
-rectal exam
-ultrasound exam
-vaginal speculum exam
-uterine culture
When is artificial lighting used and how?
From December 1-15th with a 200W incandescent light for approximately 16hrs/day.
What are the 4 ways of modifying the estrous cycle?
1) Prostaglandin
2) HCG (human chorionic gonadotropin)
3) Progesterone
4) Artificial lighting
Describe how prostaglandin works and when it's given.
-causes regression of CL
-causes estrus in 4-7 days
-mares may react with transient sweating, trembling, and crampiness
-administer at least 5 days after natural estous to be effective
How does HCG work, and what does HCG stand for?
-Causes LH activity
-Induces ovulation in 24-48 hours
-Follicle size must be greater than 32mm to use
-HCG= human chorionic gonadotropin
What is progesterone used for and what may accompany it?
Used to keep mares out of heat if aborting preganancy is normal. It is used during transitional phase along with prostaglandin do regulate time of estrus.
What is the common name of progesterone given orally?
What is the purpose of the Kasslic's surgery (spelling?)?
-mares vulva sticks out further than vulva allowing contamination
How is Kasslics surgery performed?
-tie tail away
-clean area and steralize
-local anesthetic around rim
-cut away outer layer of skin to be sutured
-suture from bottom up leaving room to urinate.
*sutures need to be removed before parturition!