Where is the semen deposited in ewe when doing AI?
Internal os of the cervix
What are the conception rates using fresh semen?
Frozen semen?
Depositing semen into the _______ vagina of the ewe results in a conception rate of 50-60%.
Anterior vagina
What affects puberty/onset of puberty in small rumis?
Sheep are ______ day breeders?
Short day
Describe Photoperiodicity’s effects on the ovine.
short day length ⇒ increase melatonin⇒
**increased GnRH = cyclicity **
(increased sensitivity to ovarian estradiol ⇒FSH & LH pulses ⇒Follicle development & ovulation)
What is “Flushing/Flush Feeding”?
Why do we do it to ewes?
How long is the estrous cycle in the doe?
18 - 22 days
(Doe = female goat)
What is the gestation length of the ewe and doe?
5 mo.
(145 - 150 d)
How long does it take the ova to move to the ewe’s uterus?
72 hrs
(3 d)
When does implantation occur in the ewe?
begins ~ d. 18
The ewe’s CL is the primary progesterone source until what day?
~day 70
Is the first heat often “visible” in the ewe?
NO
1st heat is usually “Silent”
What must you have in place in order to establish a “Lambing Season”?
Why do they use Synchronization programs in
small rumis?
What is the Ram/Buck Effect?
Rams/bucks isolated from ewe/does for 4-6 weeks
Introduction of a teaser male or breeder male into an all female herd will induce estrus w/in 3-4 days due to the pheromones produced by the male.
What must be done in order for the Ram/Buck Effect to be successful?
How long are CIDRs or Impregnated Sponges/Pessaries placed into the anterior vagina of the ewe? the doe?
What hormone do they utilize?
In what phase of the estrous cycle is PGF2a effective?
Luteal phase
Describe how PGF2a can be used to
synchronize ewes & does.
How can you bring transitional ewes into estrus?
What is the uterine transport time in the sheep?
2 to 4 days
When does maternal recognition of pregnancy occur in the ewe?
**Day 12 **
(Interferon-t and rapid elongation of trophoblast)
When does implantation of the embryo occcur in the doe and ewe?
d. 18 of gestation