Sheep & Goat Reproduction Flashcards
Taught by Dr. Hilari French
When does puberty usually occur in sheep and goats?
5-15 months (or >60% of adult body weight)
T/F: Rams with big balls come into puberty faster than their small-balled counterparts
True
Bigger scrotal circumference = come into puberty faster
T/F: Sheep and goats are both short-day breeders
True
Approximately how long is the estrous cycle in sheep?
17 days
Approximately how long is the estrous cycle in goat?
21 days
T/F: In the sheep, production of P4 is dependent on CL
False
- In the goat, production of P4 is dependent on CL*
- There is placental production of P4 in the sheep*
What is the length of gestation in sheep? What about goats? What about racoons?
- Sheep: ~147 days
- Goat: ~150 days
- Racoon: ~64 days
Reproductive manipulation in small ruminants is approached from the standpoint of where the doe is in her cycle. In the transitional period, the Buck or Ram Effect is often utilized.
What is it?
Take the buck away for 30 days or so & then bring him back as the day gets shorter (starting to cycle) to result in an LH surge.
This can however be hard for the owner because they have to take him off the farm & bring him back at 30 days
How long can this stay in the sheep or goat?
12-14 days
What is the dose of Melengesterol Acetate (MGA) labeled for use in sheep and goats?
n/a
MGA is NOT LABELED for sheep/goats
T/F: Progestin sponges may be used for manipulation of the cycle in sheep such as synchronization of estrus
True
T/F: MRP in the ovine is characterized by the presence of Interferon tau (IFN-τ)
True
What type of placentation is observed in sheep and goats?
Cotyledonary epitheliochorial placentation
The fetal heartbeat can be detected on ultrasound in sheep and goats at ~day ____
~day 25
Placentomes can be seen on transabdominal ultrasound in sheep and goats at ~day ____
~day 35
Identify these structures
Placentomes
What are the two most common causes of dystocia in small ruminants?
- Fetal posture abnormalities
- Multiple fetuses trying to exit at the same time
________ occurs due to failure of the cervix to completely dilate
ringwomb
Relatively common in the ewe
What’s this?
Head Snare
Good job.
T/F: Pregnancy toxemia is typically seen in the 1st trimester of pregnancy in sheep
False
Seen in final trimester
T/F: Prostaglandin is most commonly used for induction of parturition in sheep
False
Prostaglandin not effective for SHEEP, but may use to abort before day 60. It IS effective for goats though (15 mg PGF + 15 mg Dexamethasone)
T/F: Tail docking can cause vaginal prolapse in ewes
True
The placenta in sheep and goats should be expelled by ~____ hours
6 hours
- If > 6 hours, we consider it retained
-
Treatment:
- **Wait and see if expel by 12 hours if animal seems well
- Oxytocin or PGF2a
Treatment for milk fever or hypocalcemia in sheep and goats involves:
IV or oral calcium
The condition below can be seen if __________ is ingested between days 12-14 of gestation
Veratrum californicum (Skunk cabbage)
Toxic agent is alkaloid cyclopamine
T/F: Subterranean clover and alfafas can cause subclinical reproductive impairment in sheep
True!
Subterranean clover and alfafas are estrogen-producing plants
Which of the following species has a false pregnancy termed “cloud burst”?
- Mare
- Sow
- Doe
- Cow
- Bitch
Doe
Wow, look at this weak hairy lamb. He looks like his fetoplacental unit has been infected in the past, probably after oral transmission of some sort of pestivirus if I had to guess. I wonder what he has.
Border Disease Virus (BDV)
Cache Valley Disease is transmitted by ________
mosquitos
Akabane Virus are transmitted by __________
Culicoides and mosquitos
__________ is the most significant cause of abortion in sheep in North America, especially in Western USA
Campylobacter
- C. jejuni- sporadic abortion
- C. fetus fetus- large outbreaks of abortion
These target lesions and hepatic necrosis are associated with what bacterial infection in sheep?
Campylobacter
Outbreaks of Campylobacter are treated with TETRACYCLINES
T/F: Chlamydophila abortus is most commonly seen in sheep
False!
- Chlamydophila abortus* occurs in sheep too, but is most commonly seen in GOATS
- (Sheep go to camp. Goats eat clams.)*
You are called to a goat farm that had an outbreak of abortion. Upon examination of a placenta of one of the does, you see lesions suggestive of a necrotizing placentitis on the cotyledonary and intercotyledonary areas. You take a look at the feed and see nice good quality hay. What is the most likely zoonotic causative agent?
Chlamydophila abortus
Q fever (Coxiella burnetti) also causes necrotizing placentitis, but is more commonly subclinical
What zoonotic agent in sheep and goats causes placentitis of only the cotyledons (cotyledons will look white to yellow with small areas of focal necrosis) that looks kind of like a nasty pepperoni pizza?
Toxoplasma gondii
