Prepared for New River Valley Sheep & Goat Club, February 24, 2018, Pulaski, Virginia.

1. Out-of-season breeding
and accelerated birthing
SUSAN SCHOENIAN
Sheep & Goat Specialist
University of Maryland Extension
sschoen@umd.edu
www.sheepandgoat.com

2. What is out-of-season breeding?
▪ Breeding outside the normal breeding season, February-July.

3. Rationale for out-of-season breeding
▪ Market lambs/kids when prices are usually higher
▪ Fall is a great time to lamb/kid
▪ Ideal weather conditions for pasture lambing/kidding
▪ Good forage availability for lactating females
▪ Less parasite problems
▪ Less predator risk
▪ Longer lactation (dairy sheep)
▪ Component of accelerated lambing/kidding
programs.

4. Challenges with out-of-season breeding
▪ Sheep and goats are seasonal in their breeding habits.
▪ Litter sizes are smaller with out-of-season breeding.

5. What is accelerated lambing/kidding?
▪ Having a birthing interval of less than 12 months.
Having multiple birthing periods in the same year.

6. Rationale for accelerated birthing
▪ Increase productivity: market
more offspring per female
▪ Reduce fixed costs
▪ More efficient use of resources
▪ Year-round supply of lambs/kids
▪ Opportunistic marketing
▪ Reduce market risk
▪ Even out cash slow
▪ Even out labor

7. Challenges with accelerated birthing
▪ Winter birthing period required.
▪ Need birthing facility to accommodate 2/3 of
flock/herd.
▪ Better nutrition required. More supplemental
feeding. Higher quality forages.
▪ Higher health standards required.
▪ More labor required, more year-round
▪ Profitability tied to out-of-season breeding
success.

8. Seasonality of reproduction in sheep and goats
▪ Sheep and goats are seasonally
polyestrous; they have regular
reproductive/cycles in the fall.
▪ Their reproduction is governed
and cued by photoperiod (day
length).
▪ Sheep and goats are short-day
breeders.
▪ Most ewes/does have an
seasonal anestrus (non-fertile)
period (lactational anestrous,
too).
I’ll breed when
I want to --
not when you
want me to.

9. Percent ewes showing estrus throughout the year
0
10
20
30
40
50
60
70
80
90
100
January February March April May June July August September October November December
Source: Manage for seasonal change in reproduction. Productivity Best Practices:
IncreasingYour LambCrop Series (Marlon Knights,WVU).
Seasonal anestrus

10. Ease of getting goats bred throughout the year
Season begins following the: Season Ease of getting doe bred
Fall equinox
Sept 21-22
Fall
Sept 23-Dec 21
Prime
breeding season
Winter solstice
Dec 20-21
Winter
Dec 22- Mar 20
Intermediate
Spring equinox
Mar 20-21
Spring
Mar 21- June 20
Anestrous season
Most difficult time to get does bred
Summer solstice
June 20-21
Summer
June 21-Sept 22
Intermediate
Source: Out-of-season breeding. Fact Sheet Series on Meat Goat Herd Management (Stanton, Cornell University).

11. Seasonality of sheep and goats
▪ The length of the anestrus period
varies by breed; however,
considerable variation exists
within breeds.
▪ The length of the anestrus period
is inversely related to latitude
unless selection pressure was
applied (e.g. Finn, Romanov,
Dorset).
▪ Breeds that originate from
tropical climates (close to the
equator) are less seasonal than
breeds that originate from
temperate climates.
“Dorsets do it anytime (?)”

12. Less seasonal breeds
They usually have shorter anestrus periods.
SHEEP
▪ Horned and Polled Dorset
▪ Finn
▪ Hair sheep
▪ Ile de France
▪ Merino
▪ Polypay
▪ Rambouillet
▪ Rideau Arcott
▪ Romanov
▪ Others (?)
GOATS
▪ Boer
▪ Kiko (?)
▪ Myotonic (?)
▪ Nigerian Dwarf
▪ Nubian (variable)
▪ Pygmy
▪ Savanna (?)
▪ Spanish

13. Several approaches to out-of-season breeding
▪ Genetic selection
▪ Male introduction: ram or buck effect
▪ Hormonal control
▪ Light control

14. Genetic selection
▪ Choose less seasonal breeds of
females and males.
▪ Choose genetics with a
documented history of out-of-
season breeding.
▪ Crossbreed to enhance out-of-
season breeding success.
▪ Use selection to reduce seasonal
anestrus in your flock/herd;
heritability is low, but you will
make progress over time.

15. Ram or buck effect
▪ Introduction of teaser or intact
male after a period of isolation.
▪ Pheromones from male cause
non-cycling females to ovulate.
▪ Initial heat will be a silent heat
at 3-4 days after introduction,
followed by a fertile heat.
▪ Males and females must be
totally isolated (sight, smell,
sound) for at least six weeks
prior to the breeding season.

16. Ram or buck effect
▪ Most effective at improving conception when
females are on the “edge” of normal breeding
season.
▪ Males from less seasonal breeds are more effective
at inducing effect.
▪ Yearling males are less effective than mature
males.
▪ Can be used to synchronize lambing/kidding, too.
▪ More males will be needed for breeding.
▪ Used in conjunction with other strategies to
improve out-of-season breeding success.

17. Hormonal control of reproduction
▪ CIDRs were approved for sheep in 2009.
▪ Approval is pending in goats.
▪ MGA (melengestrol acetate) has also
been used to control reproduction in
sheep and goats; it is available OTC but
is not approved for sheep/goats.
▪ Unapproved products cannot be used
legally because they do not meet the
requirements of extra-label drug use,
which is limited to drugs that improve
the health of the animal.

18. Controlling reproduction with CIDRs
▪ A CIDR is a t-shaped device that is
inserted into the female’s vagina.
▪ It provides a sustained source of
progesterone.
▪ Progesterone is the hormone produced
by the corpus luteum (CL); it sustains
pregnancy and prevents estrus (heat).
▪ When the CIDR is removed,
progesterone levels decrease rapidly,
causing animals to come into heat at
the same time.

19. CIDR protocols for sheep and goats
▪ There are many protocols for using CIDRs to
induce and/or synchronize estrus in sheep
and goats.
▪ Significant differences exists in the duration
of treatment (5-21 days) and the use of
additional hormones (e.g. PG-600, PMSG,
eCG, Lutalyse) to improve success rates.
▪ Manufacturer recommends that CIDRs not
be re-used, but some producers have
successfully re-used them (proper
sterilization).
▪ Response to CIDRs is variable.

20. Cost of using CIDRs
Cost of CIDR Pregnancy rate Litter size Cost per lamb/kid*
$7 20% 1.4 $25.00
$7 30% 1.4 $16.67
$7 40% 1.4 $12.50
$7 50% 1.4 $10.00
$7 60% 1.4 $8.33
$7 70% 1.4 $7.14
$7 80% 1.4 $5.25
*Excluding labor or other treatments.

21. Increasing success rate with CIDRs
▪ Females should be in good body
condition and recovered from weaning
stress.
▪ Avoid stressing females in any way.
▪ Do not use in ewe lambs or doe kids.
▪ Less seasonal breeds will usually
respond better.
▪ Male fertility and libido is key.
▪ Use plenty of ram/buck power.
▪ For spring breeding, use PG-600®
(PMSG + hCG) in conjunction with
CIDRs.

22. Using MGA to induce or synchronize estrus
Virginia State University
▪ Feed MGA for 10 days at a rate of 1% of
body weight
▪ Works best to induce/synchronize
estrus during transitional periods.
▪ For spring breeding, would need co-
treatment with other hormone(s).
MGA
MelengestrolAcetate
Not approved for sheep/goats but
available over-the-counter.

23. Light control of reproduction
▪ Manipulate light periods to “trick”
ewes and does into coming into heat.
▪ Requires indoor housing and a dark
barn to achieve.
▪ Need to consider cost: electricity +
feed cost (while in barn)
▪ There are different protocols.
▪ Alternate between 8h dark/16h light
and 16h dark/8h light.
▪ 60 days of 24 hours light, followed by
60 days of ambient light
▪ Include males in treatment

24. Accelerated birthing programs
1. Twice per year - every 6 months
2. 8 month
▪ Overlapping 8 month
3. STAR® system
4. Opportunistic
Leaving males in all the time

25. 8 month system - 3 times in 2 years
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEPT
OCT
NOV
DEC
BREED
BREED
BREED
LAMB
KID
LAMB/KID
LAMB
KID

26. 8 month system - 3 crops in 2 years
Year JAN FEB MAR APR MAY JUN JUL AUG SEPT OCT NOV DEC
2018 BIRTH WEAN BREED BIRTH WEAN BREED
2019 BIRTH WEAN BREED
2020 BIRTH WEAN BREED BIRTH WEAN BREED
2021 BIRTH WEAN BREED
2022 BIRTH WEAN BREED BIRTH WEAN BREED

27. STAR® System – developed by Cornell University
5 crops in 3 years
• More rigid schedule
• Earlier weaning
• Re-breed faster
• Greater productivity (?)

28. Best management practices to increase your lamb crop
http://lambresourcecenter.com/production-resources/best-practice-resources/

29. Thank you. Questions? Comments?
SUSAN SCHOENIAN
Sheep & Goat Specialist
University of Maryland Extension
sschoen@umd.edu
www.sheepandgoat.com