Final Lecture 7 Flashcards
When do sheep go into puberty?
Goats?
Sheep- 5-7 months
Goats- 5-7 months *pygmys as early as 2-3 months
How much mature body weight do you need to breed goats and sheep
60-70% mature body weight
Length of cycle in sheep?
Goats?
Sheep- 17 days
Goats- 21 days
Duration of estrus in sheep?
Goats?
Sheep- 24 to 36 hours
Goats- 12 to 36 hours
When do sheep ovulation? Goats?
Sheep: 24-30 hours from onset of estrus
Goats: 30-36 hours from onset of estrus
What type of breeders are sheep and goats
Short day breeders
What manipulations do you do to the estrus cycle
Induction of estrus during transition/anovulatory season
Synchronization of estrus
Increase prolificacy (twins)
How many pregnancies is your goal with small ruminants
3 pregnancies in 2 years
How can you induce estrus during anovulatory season
Progesterone impregnated vaginal devices
Ram effect
Melatonin
Manipulate length of daylight
Describe protocol for using vaginal P4 devices in sheep
Day 0: Insert CIDR
Day 14: remove CIDR and give eCG injection
Day 17 (55 hours later): AI or mating
**or can do AI/mating once on day 16 (50 hours later) and once on day 17 (60 hours later)
What should you give after removing the P4 device
ECG injection to stimulate follicle growth and ovulation
Describe use of P4 vaginal devices in goats
Day 0: CIDR insertion
Day 9: prostaglandin and eCG injections
Day 11: CIDR removal
Day 13 (44 hours later): AI or mating
**or can do ai/mating on day 11 (30 hours later) and day 13 (48 hours later)
How does melatonin work in sheep
Advances breeding season by 4 weeks
Mimics darkness
Can implant or put in feed
How does light control protocol work
Too labor intensive to work- not practical
How can you synchronize estrus
Progesterone vaginal devices (mimics corpus luteum)
Prostaglandin (tightens estrus)
ECG (enhance prolificacy)
Describe cervical rings in the ewe
7 tortuous rings
Describe cervical rings in the doe
5 aligned rings
How many days should rams and ewes be together for natural breeding?
What should the ratio be?
27 days together
3-5/100
How many days should bucks and does be together for natural breeding?
What should the ratio be?
32 days together
3/100
Where can you deposit sperm in AI
Vaginal
Cervical
Trans-cervical
Laparoscopic
How do you diagnose pregnancy in sheep and goats
No return to estrus (doe- 21 days; sheep- 17 days)
Progesterone more than 1 ng/mL
**both are indirect tests
What does the doe use for P4?
Ewe?
CL throughout pregnancy
CL until day 50 then shifts to placenta
When can you diagnose pregnancy via US
Transrectally: day 17-60
Transabdominally: day 26- term
When can you diagnose pregnancy through radiography
Best more than day 90 but could be possible after day 58
