Prostaglandin
An injection of prostaglandin F2a (PGF2a) is given at a random stage of the cycle. Animals with an active corpus luteum (CL) will undergo CL regression after the PGF2a challenge and will come into heat between 2-7 days after the shot. Animals detected in estrus can be bred. Only those animals not showing heat (and not bred) after the first shot, will receive a second PGF2a injection 11-14 days after the first PGF2a and should be bred accordingly. It is not recommended to conduct TAI after a PGF2a synchronization program, since the follicular wave was not synchronized and the stage of follicular maturation is uncertain.
FEATURES:
* Effective and inexpensive program to breed dairy and beef heifers and beef cows. * Prostaglandin causes regression of the CL. Bred animals should be dropped from the rest of the treatment. * Young heifers (i.e. 11-12 months of age) and early postpartum cows (less that 30 DIM) should not be bred after the first shot. * By rectal palpation or ultrasound examination, you can also determine the presence of a Corpus Luteum (CL), and only these animals will receive the first shot. The second shot will be given to animals not bred and/or not receiving the first shot.
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MGA
(This product is not approved for lactating dairy cows.) Feed 0.5 mg/head/day of MGA (Melengestrol Acetate) for 14 days. MGA is generally fed in a grain carrier and either top dressed onto other feed or batch mixed with larger quantities. Inject a prostaglandin 31 days following the first MGA feeding.
PROCEDURE: DAYS 0-14: Feed MGA DAYS 14-31: DO NOT BREED DAY 31: Inject PGF2a DAY 33-37: Breed after synchronized estrus
7/11
Seven-eleven Synch is a short term MGA program. Cows are bred after 19-23 days compared to 33-37 days described for MGA.
PROCEDURE: DAY 0-7: Feed MGA (0.5mg/head/day) for 7 days. DAY 7: Inject Lutalyse (PGF2a) on the last day of MGA feeding. DO NOT BREED after this heat. DAY 11: Inject GnRH. DAY 18: Inject Lutalyse (PGF2a). DAY 19-23: Breed after synchronized estrus.
OVSYNCH
OvSynch uses PGF2a and GnRH to synchronize ovulation in lactating dairy cows. OvSynch was the first synchronization protocol developed that allowed for timed AI (TAI) resulting in conception rates similar to that of A.I. after a detected estrus.
PROCEDURE: DAY 0: Inject GnRH to ovulate follicle and start a new follicular wave (ie: 3-5 pm) DAY 7: Inject PGF2a to regress CL (ie: 3-5 pm) DAY 9: Inject GnRH to ovulate follicle (ie: 3-5 pm) DAY 10: Timed AI 12-16 hours after second GnRH - (ie: 7-9 am)
* GnRH causes ovulation and initiation of a new follicular wave. * Prostaglandin causes regression of the corpora lutea. * The second GnRH synchronizes the time of ovulation of the dominant follicle of the follicular wave that began growing after the first GnRH injection. * Cows don't necessarily need to respond to the first GnRH injection to synchronize to the second GnRH injection.
OVSYNCH-56
OvSynch-56 is a new modification of the original protocol that gives the second GnRH injection 56 hours after PGF2a and TAI 16 hours later (72 hours after the PGF2a. OvSynch-56 improved conception rates in almost 10 percent compared to OVSynch.
* Should be used in conjunction with PreSynch. * OvSynch-56 improved conception rates in almost 10 percent points compared to OvSynch. * Cows detected in estrus should be bred accordingly. * Allows more time for follicular maturation compared to OvSynch.
PRESYNCH
PreSynch is a modification of OvSynch in which two PGF2a injections 14 days apart are administered 14 days before initiation of the first GnRH injection of OvSynch. PreSynch improves first service conception rate compared to OvSynch and is a good strategy for programming cows to receive their first postpartum timed A.I.
* This system requires a long duration and timing. It is good for dairy cows that will receive their first postpartum timed A.I. The figure above shows a time line of DIM, thus a cow receiving TAI at 68 DIM, should receive her first PGF2a. Injection at 30 DIM. * Not a good resynchronization tool because of the long duration. * Studies have shown that conception rate was greater for cows receiving PreSynch vs. OvSynch.
COSYNCH 48
CoSynch is a specific form of OvSynch in which the timed AI occurs at the time of the second GnRH injection 48 hrs after prostaglandin injection. The advantage of CoSynch 48 is that one less handling is required for each cow compared to OvSynch. The disadvantage of CoSynch is that conception rates may not be optimized compared to timed A.I. at 12-16 hrs after OvSynch.
PROCEDURE: DAY 0: Inject GnRH to ovulate follicle and start a new follicular wave DAY 7: Inject PGF2a to regress CL (ie: 8 am) DAY 9: Inject GnRH to ovulate follicle and Timed AI (ie: 8 am)
* Pregnancy loss is less for the CoSynch System as compared to the other systems. * Breeding too late (+/- 32 hours post second GnRH injection) decreases conception rate. * Due to reduced pregnancy loss with CoSynch, the calving rate is comparable to the OvSynch System.
COSYNCH 72
CoSynch 72 is another form of OvSynch in which the timed A.I. and second GnRH injection occur simultaneously 72 hours after PGF2a. In research trials, CoSynch 72 has showed to increase conception rates as compared to CoSynch 48 and OvSynch. This increase in fertility, however, has been demonstrated only in conjunction with the PreSynch program.
PROCEDURE: DAY 0: Inject PGF2a to regress CL. DAY 14: Inject PGF2a to regress CL. DAY 28: Inject GnRH to ovulate follicle and start a new follicular wave (ie: 8 am) DAY 35: Inject PGF2a to regress CL (ie: 8 am) DAY 38: Inject GnRH to ovulate follicle and Timed AI (ie: 8 am)
* Conception rates increased by one more day of follicular maturation before GnRH injection. * PreSynch enhances a higher proportion of cows ovulating to the first GnRH injection, thus, most cows will start a new wave, and will have a follicle capable to hold up to 72 hours after PGF2a without premature estrus or ovulation. * It is not recommended to administer CoSynch 72 without PreSynch. * Enhanced fertility when estrus detection is conducted after PGF2a on day 35.
CIDR SYNCH
CIDR Synch is an OvSynch program with the addition of a CIDR inserted for 7 days (inserted at the time of first GnRH and removed at the time of PGF2a injection). It can be also used in conjunction with CoSynch programs as follows. Dairy cattle: Use CIDR with CoSynch 48 or CoSynch 72. Beef cattle: second GnRH and TAI should be conducted 54 h after CIDR removal in heifers (CIDRSynch 54) and 60 h in cows (CIDRSynch 60). When using this program in Dairy or Beef heifers, the first GnRH shot may not be given, achieving similar results. Two days after CIDR removal, administer GnRH and TAI 16 hours later (CIDRSynch). For CoSynch options, administer GnRH and TAI simultaneously as described above.
PROCEDURE: DAY 0: Insert CIDR and inject GnRH DAY 7: Remove CIDR and Inject with PGF2a DAY 9: Inject GnRH and Timed AI (CIDRSynch 48 or CIDRSynch 54) OR DAY 10: Timed AI (CIDRSynch or CIDRSynch 60)
* CIDRs provide progesterone as a means to deal with variation in stage of the estrus cycle. * CIDRs induces cyclicity in anestrous females increasing their probability of a fertile ovulation. * Early heats are prevented. * CIDRs is the most reliable strategy for TAI in dairy heifers.
SELECT SYNCH
In the SelectSynch program, the second GnRH is not administered, and cows are observed for estrus and inseminated after heat detection following the PGF2a injection. SelectSynch can be used in conjunction with TAI in a program called HybridSynch, by inseminating cows detected in heat after PGF2a and conducting TAI+GnRH injection for animals not detected in estrus by 84 hours after PGF2a.
PROCEDURE: DAY 0: Inject GnRH to ovulate follicle and start a new follicular wave (ie: 3-5 pm). DAY 7: Inject PGF2a to regress CL (ie: 3-5 pm). DAY 7-10: Inseminate animals observed in estrus. DAY 11: TAI and GnRH for animals not observed in estrus by 84 hours after PGF2a.
CIDR 6
It is a short term progesterone treatment that allows synchronization of estrus with acceptable conception rates. It is especially useful to synchronize estrus in dairy heifers and beef cows and heifers.
PROCEDURE: DAY 0: Insert CIDR DAY 6: Inject with PGF2a DAY 7: Remove CIDR DAYS 7-11: Inseminate on detected estrus
* Progesterone release through controlled diffusion within the insert. * Plasma progesterone level rises to 4µg/ml in one hour. * One use only for biosecurity control of venereal and blood borne diseases. * PGF2a allows for regression of the CL, follicular maturation, therefore, estrus behavior, and ovulation. * Progesterone induces anestrus/prepubertal animals to cycle.
CIDR 7
Similar to CIDR 6, but PGF2a injection and CIDR removal occur simultaneously on day 7. If you want to conduct timed A.I., administer GnRH and A.I. simultaneously 48 hours after the CIDR removal and PGF.
PROCEDURE: DAY 1: Insert CIDR DAY 7: Inject with PGF2a and remove CIDR DAYS 8-10: Inseminate on detected estrus
* Best program for timed A.I. heifers. * Similar to CIDR 6. * One less handling compared to CIDR 6. * Similar estrus expression and fertility as compared to CIDR 6.
RESYNCH 0
Based on 35% average conception rate in the U.S., you will have around 65% non-pregnant cows after a single insemination. Since your goal is to get them all pregnant, it makes sense to identify open cows as early as possible and resubmit them for a second AI service in a reduced period of time. Resynchronization is a strategy by which non pregnant cows are resubmitted for a second AI service quickly after pregnancy diagnosis using OvSynch type protocols. In this program, the first GnRH for the resynchronization is given to open cows at herd check (day 0), which should be day 26-33 after first insemination. It is not recommended to start resynchronization before day 26 because of low fertility experienced in research trials.
PROCEDURE: DAY 0: Timed AI DAY 33: Pregnancy check, and Inject GnRH only to open cows. DAY 40: Inject PGF2a to resynchronized cows on day 33. DAY 42: Inject GnRH and TAI according to the program selected.
* Resynchronization is an aggressive strategy that should be combined with early pregnancy diagnosis (ideally ultrasound) to get the greatest advantage. If you are not using ultrasound go to day 33-40 for pregnancy diagnosis. * If using HeatSynch, give ECP on Day 8 instead of GnRH on Day 9 and TAI on Day 10.
RESYNCH -7
ReSynch -7 is an even more aggressive resynchronization strategy in which the first GnRH injection for the second synchronization (resynchronization) is given 7 days before the pregnancy diagnosis (day 0). Although cows receive a GnRH at unknown pregnancy status, GnRH does not have negative impact on pregnant cows. By using resycnh -7 open cows receive PGF2a immediately after pregnancy diagnosis, and are inseminated 2 (CoSynch) or 3 (OvSynch) days after pregnancy check. With this program you will resubmit all open cows for a second A.I. one week earlier compared to ReSynch 0.
PROCEDURE: DAY 0: Timed AI DAY 26: Inject GnRH to all cows (unknown pregnancy status). DAY 33: Pregnancy check. INJECT PGF2a ONLY TO OPEN COWS. DAY 35: Inject GnRH and Timed AI according to the program selected.
* Do not conduct ultrasound before day 33 post breeding, since you would be giving GnRH earlier that Day 26. Administration of GnRH before Day 26 post TAI may reduce you possibilities of success. * Rapid ReSynch, a modification of ReSynch, gives PGF2a to open cows at the time of pregnancy diagnosis, but does not administer the first GnRH. This program might yield inconsistent results because no follicular wave is synchronized, thus stage of follicular development at Timed AI is unknown.
FASTBACK
Use a new CIDR device to synchronize return to estrus for animals failing to conceive to the first AI. Although CIDR is approved for use on all dairy and beef animals, this program is suggested only for beef and dairy heifers due to management issues.
PROCEDURE: Remove CIDR seven days after administration (21 days after first A.I. service.) Detect for heat during next four days. Breed/Inseminate on detected heat.
DO NOT USE PGF2a (Lutalyse, Estrumate, Prostamate, or Insync,) WHEN USING THE FAST BACK BREEDING PROGRAM.
PROCEDURES: DAY 0: - First A.I. DAY 14: Insert CIDR DAY 21: Remove CIDR. DO NOT USE PGF2a DAYS 22-25: Heat Detect, 2nd A.I.
* Create a second synchronized heat and gain a better opportunity for heat detection, resulting in a higher pregnancy rate.
HEATSYNCH
Important: Since ECP was withdrawn from the market by the Federal Drugs Administration (FDA), there is not commercial Estrogen for use in dairy cattle available in the United States. HeatSynch is an alternative to OvSynch in which 1.0 mg of estradiol cypionate (ECP) is administered 24 hours after the PGF2a injection of OvSynch to induce ovulation rather than administering GnRH 48 hours after PGF2a. Overall, HeatSynch results in similar reproductive performance to OvSynch but may not be effective for synchronizing anovular cows.
* ECP is administered 24 hours after the PGF2a injection instead of 48 hours used GnRH. * Timed A.I. is 48 hours after the ECP injection. * Not as effective as GnRH for inducing ovulation in anovular/anestrus cows. * Lower cost compared with GnRH. * Study recommendation is to breed any cows detected in standing estrus by 24 hours after the ECP injection to improve overall response to the protocol. Cows not detected in estrus at 24 hours then receive timed A.I. at 48 hours after ECP.