Pregnancy Patterns in the Mare- Lecture 16 Flashcards
Ejaculation takes place in…
uterus
Infundibulum
Covers ovulation fossa
Ampulla
Sperm passage
Where does fertilization happen?
Ampullary-isthmic junction
Embryo transport to uterus length?
5.5 to 6 days.
Compact morula
6 day old structure. Has zona pellucida.
Blastocyst
Found in uterine lumen. Loses zona pellucida. Structure is 7 to 8 days old. Has inner cell mass, blastocoele cavity, and has a capsule.
Capsule is unique to mares and is made up of a glycoprotein structure.
Expanded blastocyst
Day 7 structure. Can be seen with naked eye. Still has inner cell mass.
UFO
Unfertilized oocyte. Compact football shape. Dark cells, clearly dead. Not expelled out of uterus, must be flushed to retrieve.
Twins
Not well tolerated in mares. Recommended termination of one of the fetuses.
Early embryo nutrition
Young embryo must be mobile for 17 days. Yolk sac depletes over time.
Endometrial cups
Comes at day 37. Sticks around for 150 to 200 days. If pregnancy ends after day 37 then cup remains causing a pseudopregnancy.
Relative maternal progesterone concentrations
image
Placenta
Diffuse.
Epitheliochorial.
Non-deciduate.
Microplacentomes.
Length of gestation
320-360 days
Fetal maturation
Occurs in the last week of gestation. Cortisol rise in last 48 hours. Premature delivery is devastating due to this, lungs ect. are not ready till after cortisol rises.
Colostrum
Has immunoglobulins. Foal has to receive in first 8 to 12 hours.
Mammary secretion of electrolytes.
Changes correlated with fetal maturity. Ca> 40 mg/dl.
Increased K and decreased Na.
Cervical dialtion
Occurs prior to parturition. Faster delivery. Improved neonatal adaptability.
Stage 1 of parturition
1-4 hours.
Fetus (hopefully) changes position so feet and head face out.
Stage 2 of parturition
30-60 mins.
Fetus expulsion.
Stage 3 of parturition
Less than 3 hours.
Placental expulsion. If over 3 hours, considered retained. Can be an emergency.
