Small Ruminant Flashcards
What are the diameter of a mature ovulatory follicle?
10mm
True/False: caruncles form after maternal recognition of pregnancy
false, they are born with them
You are performing an necropsy on a sheep and notice black caruncles in the uterus, is this pathogenic
no, sheep can have black caruncles normally
Which small ruminant is AI per vagina more difficult? why?
the ewe because she has 4-5 interdigitating annular rings
True/False: does have 3-5 interdigitating annular rings
false, their annular rings do not interdigitate
When is the average onset of puberty?
6-9months or at 65% of mature weight
What is the seasonality/status of the SR esturous cycle?
seasonally polyestrus, short day breeders
What is the average estrus cycle of the ewe?doe?
ewe: 17 days
doe: 21 days
What is the biggest difference in behavioral estrus between the ewe and doe
estrus in the ewe is very subtle, the biggest sign is standing
estrus in the doe is obvious, they tail flag, vocalize, urinate frequently, and stand
When is the average time of SR ovulation
12-18 hours after the start of estrus
What 5 factors can affect ovulation
number of ovulations
nutrition
breed
presence of male
exogenous GnRH
When is testicular descent in male SR?
at 80days of gestation
When is the onset of male SR puberty
6-9mos, but can have mature sperm in the epididymis as early as 3 months
50-60% of adult weight
When does the penis separate from the prepuse in SR?
5 months
What is the earliest a buck will demonstrate libido?
1 month
What is the average volume of buck ejaculate?
0.5-2ml
What is the longevity of buck fresh ejaculate
24 hours
Only ____ % of sperm penetrate the cervix
5-10
True/False: during the non-breeding season sperm quality may be reduced
True
How would you respond to a client requesting to collect and preserve their bucks semen in June
generally advise against since you wont have great results, would be better to wait until oct/nov
What are 3 male dominance behaviors
sodomy
dominance effect
audience effect
What is the gestation length of SR?
145-150 days
True/False: twins/triplets pregnancies rarely survive
false, they are common
When does an embryo enter the uterus
4days
If you are ultrasounding and find an embryo in the contralateral horn from ovulation how many fetuses are you likely to have? why?
at least 2 because a single embryo will not migrate to the non ovulatory horn
When is maternal recognition?
day 12
When is embryo attachment?
day 14-18
What type of placenta do SR have?
epitheliochorial cotyledonary
Which SR is CL dependent?
doe
At what point are ewe pregnancies not CL dependent? what takes over progesterone production
after 50 days, the uterus
A client calls you and wants to abort her doe’s pregnancy at day 65, is this possible? what if it was a ewe?
yes this is possible as the CL is still receptive to prostaglandin. it is not possible if it is a ewe because the uterus has taken over progesterone production so luteolysis will not affect maintenance
When does the majority of fetal growth occur? how does this effect management of the ewe
85% of fetal growth occurs in the last two months of gestation. This means it is important to increase nutrition the last trimester especially calcium to support growth and prevent toxemia
True/False: penning a ewe/doe the moment you notice signs of parturition is the best way to facilitate lambing/kidding
false, exercise/movement helps prevent dystocia
Explain the parturition cascade of the ewe
-fetal cortisol triggers production of 17 alpha hydroxylase by cotyledons
-switch from P4 to E2 production by uterus
-increased estrogen stim PGF2alpha, oxytocin receptors, release of relaxin
Stage one lasts how long in the ewe and doe
ewe: 2-6 hours
doe: 1-10 hours
How long does stage 2 last?
ewe:30 min-2 hours
doe: less than an hour
How long does stage 3 take?
ewe: 1-8 hours
doe: within 12 hours
When are fetal membranes considered retained?
> 12 hours
