Reproductive management in small ruminants
Feb 2012
M.A. Driancourt, MSD AH, R&D Pharmaceuticals
Backbone of the presentation
1. What are the main reproductive features of Middle East sheep and goat
breeds?
2. What are the consequences on these physiological features on
production?
3. What are the technical options to break seasonal anoestrus?
4. What are the technical options to synchronize estrus during the
breeding season?
5. How can we improve fertility?
6. How can prolificacy be improved?
What are the main reproductive features of Middle East sheep
and goat breeds?
Awassi sheep
• Display a seasonal pattern of
reproduction
• Tend to display a late puberty
• Commonly produce a single lamb
(low prolificacy)
• Are good milk producers
3
What are the main reproductive features of Middle East sheep
and goat breeds?
Damascus goats
• Display a seasonal pattern of
reproduction, with a variable
breeding season (June to Oct
in Jordan or Sept to Feb in
Cyprus)
• Tend to display a late puberty
• Are mildly prolific (1.5 kid per
litter)
• Are good milk producers
(500kg/lactation)
4
What are the main reproductive features of Middle East sheep
and goat breeds?
Links between month of the year and cyclicity in sheep and goats
% of females in estrus
Transition
BS
Transition
anoestrus
BS
Very seasonal
breed or
female
100
Less seasonal
breed or
female
50
0
Jan
May
Dec
Sept
5
Month of the year
What are the consequences on these physiological
features on production?
The seasonal pattern of reproduction does not allow to have
reproduction timed to generate milk or lamb meat when prices are
highest.
The seasonal pattern of reproduction may not always fit with the
periods when forage and feedstuffs are available to cover the
production needs of the late pregnant and lactating ewes or the
growth needs of the lambs
Low prolificacy negatively affects the income of the farmers
The random pattern of cyclicity between individual ewes of a flock does
not allow to use AI (and the associated diffusion of genetic merit)
6
What are the consequences on these physiological
features on production?
Technical needs triggered by these physiological features
•
Breed during anoestrus (hence “break” anoestrus)
•
Synchronize estrus during the breeding season (to use
AI )
•
Increase prolificacy
7
What are the technical options to break seasonal anoestrus?
• Use progestagen/progesterone impregnated
vaginal devices
• Use the ram effect
• Use melatonin
8
What are the technical options to break seasonal anoestrus?
SHEEP
• Use progestagen/progesterone impregnated vaginal
devices
Three types of devices are available: cronolone (20mg) impregnated
sponges (Chronogest CR, MSD AH), MAP (60mg) impregnated sponges
and CIDR(0.3g progesterone)
55h
Typical treatment schedule
Day 0
Sponge
insertion
Day 14
Day 17
Sponge
removal and
PMSG injection
AI or
mating
If mating is used, preparation of the rams
(flushing, light treatment or melatonin) and a
suitable ewe to ram ratio are needed
9
What are the technical options to break seasonal anoestrus?
•Use progestagen/progesterone
impregnated vaginal devices (+ 400IU
PMSG and mating) in Awassi ewes
Ozyutlu et al 2010
10
SHEEP
What are the technical options to break seasonal anoestrus?
GOAT
• Use progestagen/progesterone impregnated vaginal
devices
Three types of devices are available: cronolone (20mg) impregnated
sponges (Chronogest CR, MSD AH), and CIDR
44h
Typical treatment schedule
Day 0
Sponge
insertion
Day 9
Day 11
Sponge
removal
Prostaglandin
injection and
PMSG
administration
Day 13
AI or
mating
Bucks also need to
be prepared!
11
What are the technical options to break seasonal anoestrus?
•Use progestagen/progesterone
impregnated vaginal devices
Fertility
GOAT
Alpine & Saanen goats
Parity 1
55.3%
Parity 2
73.7%
Parity 3
55.9%
400UI
PMSG
50.9%
500UI
PMSG
62.9%
600UI
PMSG
68.1%
Parity 4
75%
Parity 5
58.8%
Intervet registration files
Prolificacy= 1.97+/- 0.8
12
What are the technical options to break seasonal anoestrus?
•
Use the ram effect
Pre-requisites:
•
Target a breed with a light anoestrus or females
during the transition period
•
Ewes/goats need to be away from the rams/bucks
for at least a month
•
The rams/bucks need to be prepared (light
treatment/melatonin)
13
What are the technical options to break seasonal anoestrus?
•
Use the ram effect
Estrus and formation of normal corpora lutea do not
happen immediately!
Chemineau et al 2006
14
What are the technical options to break seasonal anoestrus?
•Use melatonin ear implants (18mg)
I
Implants need to be inserted between 50 and 70 days before breeding
Control
Sponge +
PMSG (450IU)
Melatonin
Fertility
65%
78%
78%
Prolificacy
1.26
1.50
1.55
(Gomez et al 2006), Manchega ewes
15
What are the technical options to break seasonal anoestrus?
Take home message
Submission
rate
Fertility
Prolificacy
AI use
+++
++
+++
Yes
Ram effect
+
+
+
No!
Melatonin
implant
++
++
++
No
(no synchro)
Progestagen
sponges
16
What are the technical options to synchronize estrus during
the breeding season?
SHEEP
• Use progestagen/progesterone impregnated vaginal
devices
• Use of Ovsynch type protocols
• Use of double prostaglandin protocols
17
What are the technical options to synchronize estrus during
the breeding season?
SHEEP
• Use progestagen/progesterone impregnated vaginal
devices
Three types of devices are available: cronolone (20mg) impregnated sponges
(Chronogest CR, MSD AH), MAP (60mg) impregnated sponges and CIDR (0.3g)
55h
Typical treatment schedule
Day 0
Sponge
insertion
Day 14
Day 17
Sponge
removal and
PMSG injection
AI or
mating
If mating is used, a suitable ewe to ram ratio
needs to be respected
18
What are the technical options to synchronize estrus during
the breeding season?
•Use progestagen/progesterone
impregnated vaginal devices
SHEEP
Dairy
(Lacaune)
Dairy
(Manech)
Meat
(Texel,
Vendeen)
Fertility
71%
52.3%
63.2%
Prolificacy
1.69+/- 0.67
1.45+/- 0.77
1.62+/-0.68
Intervet registration files
19
What are the technical options to synchronize estrus during
the breeding season?
SHEEP
Sponges allow to obtain improved reproductive
performance in Awassi ewes managed in a “3
lambings in 2 years” management system (6 breeding
periods)
Zarkawi et al 2011
20
What are the technical options to synchronize estrus
during the breeding season?
GOAT
• Use progestagen/progesterone impregnated vaginal
devices
Three types of devices are available: cronolone (20mg) impregnated
sponges (Chronogest CR, MSD AH), and CIDR
44h
Typical treatment schedule
Day 0
Sponge
insertion
Day 9
Day 11
Sponge
removal
Prostaglandin
injection and
PMSG
administration
21
Day 13
AI or
mating
What are the technical options to synchronize estrus during
the breeding season?
•Use progestagen/progesterone
impregnated vaginal devices
Damascus goats
GOAT
Al Merestani et al (2003)
22
What are the technical options to synchronize estrus during
the breeding season?
SHEEP
• Use of Ovsynch type protocols (Deligiannis et al 2005, Titi et al 2010)
GnRH
Day
0
GnRH
Day
0
PGF2 a
AI
GnRH
5
6.5
PGF2 a
7
50%
fertility in
Greek
ewes
Rams in
5
6
23
60%
fertility
in
Awassi
ewes
What are the technical options to synchronize estrus during
the breeding season?
•Use of Ovsynch type protocols
(Holtz et al 2008) Boer goats
N=24/group
GOAT
Sponge
Ovsynch
+ prostaglandin and
250IU PMSG 48h before
sponge removal (AI 43h
later)
( 4µg Buserelin on d0,
prostaglandin on d 7 and
4µg buserelin on d 9 with
AI 16h later)
% goats in estrus
100%
96%
Fertility (day 30post
AI)
50%
56%
Prolificacy
1.83 +/- 0.23
1. 86 +/- 0.14
24
What are the technical options to synchronize estrus during
the breeding season?
•Use of double prostaglandin
protocols ( 7 to 11 days apart)
SHEEP
control
Double PG
Conception (% US
positive 30 days
post AI)
88%
63%
Prolificacy
1.58
1.27
Fierro et al 2011
25
What are the technical options to synchronize estrus during
the breeding season?
Take home message
• Vaginal sponges are the best approach
• Ovsynch may be an alternative in goats
• Double prostaglandin treatment reduces fertility
When a successful synchronization is obatined,
1. Diffusion of genetic merit becomes possible (AI)
2. Breeding can be focussed on a narrow part of the year (labor efficiency)
3. Lambing is limited to a narrow time period (labor efficacy)
4. An homogeneous lamb crop is ready to be sold at a set time every year
26
How can we reach optimal prolificacy?
What is optimal prolificacy?
• An homogeneous crop of twins! (no triplets)
• If
1. maternal behavior of the ewe is OK!
2. Milk production of the ewe is adequate!
27
How can prolificacy be improved?
• Use PMSG at removal of progestagen/progesterone
impregnated vaginal devices
• Use Androvax, a vaccine against an ovarian steroid
• Use genetic introgression of a prolificacy gene (such
as Fec B) into your sheep breed
28
How can prolificacy be improved?
•Use PMSG at removal of progestagen/progesterone
impregnated vaginal devices
Ovulation
rate
5
4,5
4
3,5
3
Galway
T imadhite
romney
2,5
2
1,5
1
0,5
0
0
375
750
Dose of PMSG (IU)
Quirke et al 1986
29
How can prolificacy be improved?
• Use Androvax, a vaccine against an ovarian steroid
A vaccine against a steroid (androstenedione coupled to a carrier (bovine lactalbumin) in
a DEAE adjuvant), applied as a primary and a booster on the first year of treatment.
The recommended vaccination schedule is
First vaccination (2ml): 8 to 10 weeks before joining
Booster (2ml): 4 to 6 weeks before joining
The antibodies reduce negative feedback of the steroids on LH secretion. The increased
frequency of LH pulses increases the proportion of double ovulations (by around 20%)
Not affecting seasonality (not inducing ovulation in anoestrous ewes)
Not synchronizing ovulation, hence compatible with mating by rams
A booster is needed every year to obtain the prolificacy increase, but may be skipped if
the environment is too harsh
30
How can prolificacy be improved?
• Use Androvax, a vaccine against an ovarian steroid
Prolificacy data from 27 farms in NZ
31
How can prolificacy be improved?
• Use genetic introgression of a prolificacy gene (such
as Fec B) into your sheep breed
The Booroola gene (Fec B) is a major gene that has large
effects on prolificacy (but not on seasonality).
Homozygous ewes and heterozygous carrier ewes display over 5 and around 3
ovulations (vs 1 for the non carriers)
This gene acts by interfering with the signalling of bone morphogenic proteins
Its position in the sheep genome is known
By crossing a specific breed with homozygous rams and then backcrossing to
the initial breed, it is possible to introgress the Fec B prolificacy gene in that
breed, while keeping all the production features of the breed (was done with
Awassi)
32
How should fertility problems be analysed?
Questions to be asked when fertility is lower than expected
1. Is the problem physiological or pathological?
2. What evidence do I have that low fertility is only a
female problem?
3. What evidence do I have that the ewes were indeed
ready to be bred (i.e. cycling)
4. Was body condition of the ewes adequate for initiation
and maintenance of pregnancy?
5. What were the climatic conditions in the days around
ovulation and early embryonic development?
33
Conclusion : the tools to work from…
Sponges
Efficient
breeding at
all times of
the year
Improving
prolificacy
Allowing
early
breeding of
ewe lambs
Allows easy
diffusion of
genetic merit
by AI
Allows
matings by
rams
Yes
Yes( 1040%)
Yes
Yes
Yes (ram to ewe
ratio adapted to the
season)
(depending on
amount of PMSG)
Melatonin
implants
No?
Yes (15%)
No
No
Yes
Androvax
No
Yes (25%)
No
No
Yes
Genetics
Not yet
If prolificacy
genes are
introgressed
No
No
Yes
Improved
nutrition
No
Yes (10%)
No
No
Yes
34
Conclusion: how to implement these tools according to
your needs
• There are many tools that are available to move from
extensive production systems towards more intensive
ones (provided the farm technical management and food
availability allow it)
• Several steps of intensification are possible (from mild
such as the use of Androvax or melatonin implants to a
more “European” production system using sponges to
obtain three lambings in 2 years with increased
prolificacy)
35
Questions?
36