Updated: 04/19/23

Estrous Synchronization (Ovulation Induction)

and Ovsynch

Estrous Synchronization (Ovulation Induction)

and OvsynchJohn Parrish

Updated: 04/19/23

To understand how estrus synchronization and Ovsynch work along with how to use it successfully.

Learning Objective

Updated: 04/19/23

Estrus synchronization:

Why?

1. Group females for parturition:

a. Labor, Calving period

b. More uniform weaning weights.

2. Reduce time required for estrus detection.

3. Eliminate estrus detection with timed insemination:

Reduce calving seasonReduce calving season

Fertility may be higher in combination with estrus detection.Fertility may be higher in combination with estrus detection.

Updated: 04/19/23

Prostaglandins: PGF2

Lutalyse - Natural compound 25 mg dose I.M.

Estrumate - Analogue 500 mg dose I.M.

Bovilene - Analogue 1 mg dose s.q.

2-3 min

3-4 hrs

18-24 hrs

2-3 min

3-4 hrs

18-24 hrs

Half-life in blood Half-life in blood

Cattle:Cattle:

Updated: 04/19/23

Principle of PGF2 UsePrinciple of PGF2 Use

• Regress active corpus luteum» Only effective on day 5 - 17 corpus luteum

» Not effective on days:1 - 4 (CL not responsive)18 - 21 (CL already regressed)

Updated: 04/19/23

Updated: 04/19/23

LutalyseLutalyse

1 injection +palpation

Palpationto detect

CL

Inject Lutalyseto thosewith a CL 11 days

Inject Lutalyse to those not getting the 1st injection

Heat Check & Breed

Updated: 04/19/23

Principle of PGF2 UsePrinciple of PGF2 Use

• In estrus 2 - 5 days after injection» Heifers ~ 50 hrs

» Cows ~ 72 hrs

Updated: 04/19/23

Reasons for Variation in ResponseReasons for Variation in Response

• Stage of the follicular wave at time of PGF2

Day After OvulationDay After Ovulation1010OvulationOvulation

Folli

cula

r Si

zeFo

llicu

lar

Size

77

Updated: 04/19/23

Reasons for Variation in ResponseReasons for Variation in Response• Stage of the follicular wave

1010OvulationOvulation

Folli

cula

r Si

zeFo

llicu

lar

Size

Day After OvulationDay After Ovulation77

PGF2

PGF2

Updated: 04/19/23

Reasons for Variation in ResponseReasons for Variation in Response• Stage of the follicular wave

Day After OvulationDay After Ovulation1010OvulationOvulation

Folli

cula

r Si

zeFo

llicu

lar

Size

77

PGF2

PGF2

Time to response depends on stage of follicular wave!

Time to response depends on stage of follicular wave!

Updated: 04/19/23

Reasons for Variation in Response (cont.)Reasons for Variation in Response (cont.)

• Heifers react faster than cows» Follicular growth is faster in heifers

• Animals may be pregnant

• No CL may be present - Anestrus

• Brahman cattle respond poorly to the two injection system of PGF2» Recommended:

• Inject and breed all responders

• Inject 2nd treatment 11 days later to all those not bred to 1st injection and breed on estrus detection

– This approach also reduces the number of second injections needed!

Updated: 04/19/23

Management Consideration:Management Consideration:

• Have proper facilities to handle animals

• Good reproductive records

• Have enough A.I. technician help » One technician/100 cows will cause problems

» Should be around 30-50 cows/technician

• Anestrus cows don’t respond to PGF2» No CL!!!!!!

» Be sure cows & heifers cycling

• Use good fertility semen

Updated: 04/19/23

Breeding with Prostaglandins:Breeding with Prostaglandins:

1. Breed 80 hours after 2nd injection

2. Breed based on estrus after PGF2

3. Control cows bred based on estrus

Conception RateConception Rate

31 - 80%31 - 80%

67%67%

75%75%

Updated: 04/19/23

Improving Ovulation SynchronizationImproving Ovulation Synchronization

• 48 hours after PGF2 » Give GnRH

» Cause LH surge; achieved slight increase in conception rates• 3 - 4 %

Cystorelin (GnRH Analogue)Cystorelin (GnRH Analogue)

Updated: 04/19/23

Principle:

Maintain the cow under the influence of progesterone until corpus luteum regresses, remove progesterone -animal respond to progesterone with estrus 2-5 days later.

Administration:

Injection

Feed

Implant

Pessary or Control Internal Drug Release (CIDR)

Time Consuming

Mix in ration

Place in ear

Place in Vagina

Use of ProgestogensUse of Progestogens

This does not regress the CL!!!!

Updated: 04/19/23

Updated: 04/19/23

Updated: 04/19/23

EAZI-BREED CIDREAZI-BREED CIDREAZI-BREED CIDREAZI-BREED CIDR

Insert CIDRInsert CIDRwith CIDIROLwith CIDIROL

capsulecapsule

Day 6Day 6

RemoveRemoveCIDRCIDR

Detect EstrusDetect Estrusor or

InseminateInseminateFixed-timeFixed-time50 hours50 hours

From CIDIROLFrom CIDIROL

Inject PG

Inject PG

Day 7Day 7Beef Cow

Day 9-11Day 9-11Day 8Day 8

InjectInject2mL2mL

CIDIROLCIDIROL

7 Days

Triggers GnRH surge

Triggers GnRH surge

EstrogenEstrogen

Lutyalytic to day 1-4 CL

Updated: 04/19/23

Initiation of Puberty in CattleInitiation of Puberty in Cattle

• Objectives» Start follicular development

• FSH or eCG

» Progesterone need in order to exhibit estrus in response to follicular estrogen• Give progestin in either feed or vaginal insert

• Procedures» Progestin in feed or CDIR for 7 - 21 days» Follow with eCG on last day of progestin treatment» Some heifers will ovulate even if don’t give eCG

Updated: 04/19/23

Induction of Ovulation in Postpartum CowsInduction of Ovulation in Postpartum Cows

• GnRH on Day 12 - 14 postpartum» Luteinizes some follicles to produce progesterone

» First ovulation on day 35 and associated with estrus due to progesterone exposure

• Ovsynch

Updated: 04/19/23

OvsynchOvsynch

7 Days

36 - 48 hours

GnRHGnRH PGF2PGF2

8 - 18 hoursTimed AITimed AI

GnRHGnRH

Updated: 04/19/23

How Does Ovsynch Work?How Does Ovsynch Work? Ovsynch does not change conception rateOvsynch does not change conception rate Ovsynch dramatically improves service Ovsynch dramatically improves service

raterate

Updated: 04/19/23

Experimental Design

Field trial using lactating dairy cows from three herds in South-central Wisconsin

Experimental Design

Field trial using lactating dairy cows from three herds in South-central WisconsinTreatment:

Description:Estrus detection with a.m./p.m. AI

Synchronization of ovulation with timed AI

Ovsynch (n=167)

Control (n=166)

Updated: 04/19/23

MethodologyMethodology

• Voluntary waiting period = 50 days

• Pregnancy diagnosis was determined by ultrasound 32 to 38 days post-AI

• Nonpregnant cows remained in the same treatment group until diagnosed pregnant or culled from the herd

Updated: 04/19/23

Updated: 04/19/23

Pro

po

rtio

n N

ot

Pre

gn

ant

Updated: 04/19/23

Control OvsynchService DIM PR/AI DIM PR/AI

1st 83 39% 54* 37%2nd 128 45% 96* 42%

*Differs from Control, p<0.01

ResultsResults

Updated: 04/19/23

# ofAAnimal

PR/AIExpt Animals Control Ovsynch

Lactating Cows 1 546 42% 39%2 311 39% 39%

Heifers 2 155 74% 35%*

*Differs from Control, p<0.01

ResultsResults

Preg/Insemination

Updated: 04/19/23

OvsynchOvsynch

Advantages:Elimination of estrus detection for

first postpartum breedingTimed AI results in conception rates

similar to that of AI to a standing estrus

Disadvantages: Hormone Costs Can not use on heifers

Updated: 04/19/23

Ewe Estrus SynchronizationEwe Estrus Synchronization

Progestin

• CIDR

• vaginal pessary (sponge)

Updated: 04/19/23

Updated: 04/19/23

Use of Progestin in SheepUse of Progestin in Sheep

• If during the non-breeding season, induce follicular growth at time of CIDR removal » eCG (400 - 800 IU)

» PG600– Product designed for induction of puberty in gilts

– contains 400 IU eCG and 200 IU HCG

• Fertility in the breeding season is good» Use 1 ram / 10 ewes

» Fixed time insemination at 48-52 hours using laproscopic technique

Updated: 04/19/23

Ewe Estrus SynchronizationEwe Estrus SynchronizationPGF2

• Use in breeding season only

• 2 injections of Lutalyse (20 mg ) 9 days apart» No effect if ewe anestrus

Updated: 04/19/23

Induction of Puberty in the Ewe LambInduction of Puberty in the Ewe Lamb

• Progesterone 12 - 14 days and eCG on last day of treatment» Can give PG 600 in place of eCG alone

• Seasonal» Decrease light to simulate fall

» Give melatonin

• Postpartum» If attempting to have 2 lamb crops, treat like induction

of puberty

Induction of Ovulation in Anestrous EwesInduction of Ovulation in Anestrous Ewes

Updated: 04/19/23

Sow Estrus SynchronizationSow Estrus Synchronization

PGF2

» Will not cause regression of the CL until day 12 of the cycle

» Not of practical use

Progestins - Altrenogest» Common progestins (MGA) will synchronize estrus but

cause ovarian cysts

» Regumate• Product developed for horses

• Give 20 mg/day on feed for 18 days

• Estrus is 4 - 8 days after stop giving Regumate

• Only minor incidence of cysts

• Cost is $5 - $10/day

Updated: 04/19/23

Sow Estrus Synchronization (cont.)Sow Estrus Synchronization (cont.)

Wean piglets» 3 - 6 days come into estrus

Updated: 04/19/23

Induction of Puberty in GiltsInduction of Puberty in Gilts

Prepubertal (noncycling)» PG 600

• 400 IU eCG and 200 IU HCG

• Gilts can not be cycling

• Need to be > 5.5 months of age

• Gilts express heat 3 - 4 days following treatment

Updated: 04/19/23

Mare Estrus SynchronizationMare Estrus SynchronizationPGF2

• Works on CL >5 days of age and mare in diestrus

• Lutalyse» 1 ml/500 lbs. body weight

» Mare CL more sensitive than cow’s

» Side effects can be sever in mare• Sweating

• Adominal cramps, increased motility of GI tract and/or colic

• Increased heart rate

• Muscle weakness and balance problems

• All side effects begin at 5 - 10 minutes and last until 60 minutes after injection

Updated: 04/19/23

Mare Estrus Synchronization (cont.)Mare Estrus Synchronization (cont.)

• Ovulation in 8 - 9 days

• Reasons for treatment» Synchronize estrus/ovulation for artificial

insemination or embryo transfer

» Prolonged diestrus - failure of CL to regress• May remain for 3 - 4 weeks

• Low grade uterine infection

• Embryo may have died but CL did not regress

» May treat all mares entering a breeding farm• Shortens time to estrus and breeding

Updated: 04/19/23

Mare Estrus Synchronization (cont.)Mare Estrus Synchronization (cont.)

Progestins

• Regumate» Oral progestin

» Give 1 ml / 100 lbs body weight

» Treatment• Feed daily for 12 - 14 days

• On last day give PGF2

• Will be in heat in 3 - 4 days but ovulation not until day 8 after treatment

» Uses• Synchronize estrus/ovulation for breeding

• Reduce number of mares in heat on any one day to better utilize a stallion over time.

• Suppress estrus in a performance mare

Updated: 04/19/23

Induction of Ovulation in Anestrus MaresInduction of Ovulation in Anestrus Mares

• Seasonal» Increase light exposure

• 16 hours light / day (takes 30 - 60 days)

• Postpartum» Breed at foal heat

» Provide adequate nutrition and don’t see lactational anestrus