Exam 4 Flashcards
Progesterone Pregnancy Functions
-inhibits uterine contractions
-stimulates uterine secretions
-creates cervical plug
-mammary gland development
-species variation
Estrogen Pregnancy Functions
-stimulates the endometrium to increase blood flow and secretions
-needed for events leading to parturition
-mammary gland development
Estrogen sources during pregnancy
-follicles on ovary continue to grow during pregnancy
-placental membranes are the major source of estrogens for all species during pregnancy
Where does progesterone come from during gestation in sow?
It comes from the CL throughout the entire pregnancy
Where does progesterone come from during gestation in the doe?
It comes from the CL throughout the entire pregnancy
Where does progesterone come from during gestation in the ewe?
It comes from the CL in the first 40 days
It comes from the placental membranes in the last 100 days
Where does progesterone come from during gestation in cow?
It comes from the CL in the first 128 days
It comes from the placental membrane after day 128
Where does progesterone come from during gestation in the mare?
-the original CL from 35 days
-the accessory CL from days 40-180
-the placental membranes after day 160-180
Equine Accessory CL
-Stimulated by production of equine chorionic gonadotropin (ecg)
ECG
-produced by the endometrial cups
-invasion of endometrium by chorionic girdle cells of the embryonic vessilve
-increased follicular development and formation of many CL
Advantages of AI
-superior male genetics available
-reduces chance of sexually transmitted diseases
-increased coverage by selected sire
Disadvantage of AI
-increased labor costs
-requires skilled labor and periods of intensive management
-requires adequate facilities
-higher input costs
Dairy Industry AI
-90% national cow herd bred AI
Beef Industry AI
<12% national cow herd bred AI
-greater use in purebred operations or special projects
Swine Industry AI
-use is increasing
-struggle is keeping crypreserved semen alive
-now chilled not frozen semen is used
Swine is NC >90% AI
Equine Industry AI
Challenges with cryopreserved semen
Breed standards for certain things like Kentucky derby the horses must be bred by live cover
Site of Semen Deposition in NM vs AI
AI-must be in the uterus and bypasses cervix
NM-site varies by species
Ejaculate amount in NM vs AI
NM-entire ejaculate is used on one female
AI-entire ejaculate is extended on several females between (3-500)
Timing of mating between NM vs AI
NM-during estrus
AI-estrus or beginning of metaestrus to find the right time when ovulation occurs
Number of inseminations in NM vs AI
NM-one and done
AI-multiple inseminations usually twice
Cow insemination technique
yo have to find the cervix then weave through the annular rings, the struggle is making sure you don’t go through the fornix instead making sure to inseminate in the uterus instead of the uterine horn
Mare insemination technique
transvaginal with finger to find the cervical oss, making sure there is extra liquid with the insemination to prevent back flow
Sow insemination technique
-simple but must make sure it is turning the right way to get in through the corkscrew into the uterus
Sexed semen
-ability to separate x and y sperns
-allows for female heifers
not all sires can because since it takes so long to process there is a risk of sperm death