Sheep and Goat Breeding Management Flashcards
when is puberty in sheep?
4-7mo
when is puberty in goats
3-7 mo
what is the age at first breeding for sheep and goats
6-8 months
what is the source of progesterone during pregnancy in sheep
CL and the placenta after day 75
what is the source of progesterone during pregnancy in goats
CL only
what is the gestation length in sheep?
144-151 days
what is the gestation length in goats
147-155 days
false pregnancy is (common/uncommon) in goats and (common/uncommon) in sheep
common; uncommon
the length of the estrus cycle in sheep is ___ days and in goats is ___
17; 21
are goats or sheep breed dependent when it comes to ovulation rate/prolificy
sheep
is estrus more subtle in sheep or goats
sheep
what estrus traits are common to both sheep and goats
both follow the male; both have vulvar swelling; both have mucus
when there is an increase in melatonin secretion after the spring equinox, how many days does it take for the hypothalamus to start secreting GnRH
45
T/F the first estrus is silent but fertile in sheep and goats; how does this compare to horses?
T; in horses, first estrus is obvious (long, irregular) but infertile (no LH receptors)
what stops cycling naturally in sheep and goats
when FSH fails to initiate a follicular wave due to insensitivity
how long do sheep and goats cycle for before entering seasonal anestrus
4 months
how long is the breeding exposure period in sheep and goats
30-42 days
sheep and goats breed naturally in the ______ give birth naturally in the _______
fall; spring
replacement ewe females are bred at what age
7 months
lambs/kids are weaned after how many days
approx 60
what are the two accelerated lambing programs
3 in 2 (3 pregnancies in 2 years) or Cornell Star (5 in 3)
what is the goal of accelerated lambing programs
to decrease or eliminate the open and dry period
what is the biggest hurdle with accelerated lambing programs
produces manage multiple groups that lamb at different times of the year, which requires a great deal of organizational management
dairy goats are bred ____ months into lactation
7
dairy goats are dried off after how many days of lactation and for how long
305d; 2 months
kids are removed
at birth
replacement doelings are bred at ______ months of age to kid at _______
7-10; 12-15
does are milked for how many months
10
how long can buck kids be kept for
either sold right after birth or marketed after 4 months
does are bred over ____ months and kid over ___ months
3; 3
how do we prevent fluctuations in milk production due to the lactation curve
split groups into 2 and breed 1 in fall and 1 in spring
what are the 3 main reasons for estrus cycle manipulation in sheep and goats
1) shorten the breeding/lambing window
2) more efficient use of labour and facilities
3) out of season breeding
T/F most drugs in sheep and goats are used off-label
T
what hormone for estrus synchronization is NOT approved in lactating dairy animals
MGA (oral progesterone)
what hormones are available for estrus synchronization in sheep and goats?
1) oral progesterone (MGA)
2) intravaginal progesterone (CIDR)
3) injectable prostaglandin
4) injectable eCG and PMSG
what exogenous hormones would be available for use to bring a goat/sheep out of the anestrus period
eCG or PMSG; progesterone
what is estrumate
injectible PGF2α
what is an important consideration for eCG regarding purchasing
different brands have different concentrations; easy for producers to give wrong dose if they switch brands
what hormone can be mistakenly purchased in the wrong concentration due to varying concentrations between brands
eCG
after PGF2α, estrus occurs in sheep within ______h and in goats within ______h
24-72; 56-72
PGF2α have higher/lower fertility than progesterone programs
Lower
the most effective PGF2α program is
double shot 9-11 days apart
the LONG CIDR program is what duration in sheep? what duration in goats?
11-14 in sheep
14 in goat
T/F you need to use eCG for the long CIDR program
F
T/F you need to inject PGF2α at the end of the short CIDR program
T
how soon after removing the CIDR do you introduce the ram
24h
what is the ram to ewe ratio for a CIDR program
1:10
why do we give PGF2α at the end of the short CIDR program
to eliminate any CLs that may still be present
how long do you leave the CIDR in for a short program in sheep and in goats
sheep: 5 days min
goat: 7 days min
describe the CIDR program to bring a sheep or goat out of anesturs
keep in for 5-7 days; give PGF2a 1-3 days before removal if you think some animals may be transitioning and give eCG upon removal to induce ovulation; introduce males 24h after removal
what is the male:female ratio when using CIDRs or MGA to bring animals out of anestrus
1:5 - 1:7
when using MGA for estrus synchronization, what is a consideration regarding additional hormone supplementation that depends on whether the females are anovulatory or ovulatory
if ovulatory you may or may not give eCG 8h after the last feeding; if anovulatory then giving eCG is necessary
the duration of MGA feeding if animals are ovulatory is ________ and if animals are anovulatory is _________
11-14; 7-9
for light manipulation to bring sheep/goats out of anestrus, from _____ to _____ you expose them to ______ light and then from ______ to ______ you expose them to ______ light
Dec - March; 16h; March - May; 8h
T/F light manipulation works in sheep/goats during the transition period
F
the male effect is best during __________ season; poor during _________ season, and variable during _________ season
transition; ovulatory; anovulatory
If you wanted to bring a group of ewes out of the anovulatory period, what method would be the least effective:
a) CIDR program 5-7 days, give eCG upon removal
b) male effect
c) daylength effect
d) MGA program for 7-9 days, give eCG 8h after last feeding
b) male effect
If you wanted to bring a group of ewes out of the transition period, what method would be best:
a) CIDR program 5-7 days, give eCG upon removal
b) male effect
c) daylength effect
d) MGA program for 7-9 days, give eCG 8h after last feeding
b) male effect
for the teaser effect to work, what is critical about the male
new for at least 30 days and introduced abruptly
what happens following introducing a new male to a group of ewes in transition
silent estrus in 2-3 days, followed by a behaviourally normal heat (vulvar swelling, discharge, follows ram, anorexia)
non-sexually active ewes will ovulate within how many days after joining teasers
2-3 days
how does the teaser ram program work
tease with male that is “new” as of the past 30 days; females have a silent estrus in 2-3 days; replace teaser male with fertile ram no later than 14 days after introducing teaser male
for a teaser program what is the ratio of ram:ewes
1:20 - 1:25
what 2 ways to ewes respond to ram teasing
1) mate within 3 weeks after teaser introduction
2) mate within 4 weeks after teaser introduction
when some animals start to cycle ____% of the anestrus group will cycle as well
25
with natural breeding, what percentage of ewes do we want to see pregnant within their first cycle
75%
T/F CIDR losses are more common in nulliparous than multiparous ewes
T
