5-day cidr synch: the missing protocol for dairy heifers - Accelerated ...

insiderTable 1. Type of CIDR treatment and fertility of beef cows.CR (%)article will try to present some insightabout recent and promising findingstowards developing an efficientsynchronization program for heifersutilizing hormones that are availablein the U.S. market.Currently, one of the best protocolsfor dairy heifers in terms of conceptionseems to be the newly developed5-Day CIDR Synch (Bridges etal., 2008). This is the sequence ofinjection during the 5-Day CIDRprotocol: on Day 0, CIDR is appliedtogether with a GnRH injection. Fivedays later (5 complete days afterCIDR insertion!), CIDR is removedand a PGF2 αtreatment is given atthe same time. A second PGF2 αisrequired in beef and dairy cows (butnot on heifers), sometime between8 to 24 hours after CIDR removal.Then, three days after CIDR removalExperimental Groups(Source: Adapted from Bridges et al., 2008; Exp. 4)(Day 8), animals are bred togetherwith an additional GnRH treatmentat the time of A.I.The original work to develop the5-Day CIDR protocol was done byBridges et al. (2008) using beefcows as experimental units. Theirresults suggested that reducingCIDR insertion from 7 to 5 days,associated with longer pro-estrusintervals improved conceptionrates. It is important to highlightthat Bridges et al. (2008) used twoPGF2 αinjections in all trials toenhance CL regression, the firstPGF2 αwas done at CIDR removaland the second PGF2 αwas given12 hours later.This pioneer work was done by Bridgeset al (2008) and served as rationalefor several further trials using beef(Kasimanickam, et al., 2009), dairycows (Chebel et al., 2009), and dairyheifers (preliminary results shownby Dr. Thatcher at DCRC meeting –Minneapolis, MN 2009). In addition, anumber of other ongoing experimentsare to be published in the next coupleof months, and they will provide moreknowledge about the use and efficacyof the 5-Day CIDR protocol.For instance, Kasimanickam et al.(2009) tested whether two PGF2 αtreatments are actually needed atCIDR removal when a 5-Day protocolis used in beef cows. Secondarily, inthis same trial, they compared twotypes of PGF products (dinoprostvs cloprostenol) when a single PGFtreatment was given at CIDR removal.In summary, they found no differencebetween the two PGF2 αproducts.However, two PGF2 αtreatmentsseem to be necessary for maximumconception rates in beef cowsreceiving the 5-Day CIDR protocol.Finally, there is sufficient scientificevidence proving the effectivenessof the 5-Day CIDR protocol indairy heifers (data summarizedand presented by Dr. Thatcher atDCRC meeting in Minneapolis, MN– 2009). Briefly, these researchersobserved in a series of field trialsthat a single PGF2 αtreatmentgiven at CIDR removal is enough toproduce good CL regression, andoutstanding conception results thatare comparable to conception resultsachieved when heifers are bred afterregular estrus detection.Dr. Thatcher also reported similarconception rates in heifers treated

insiderTable 2. Type A & D Single vs. Double PGF in Beef Cows.Table 3. Effect of One vs. Two PGF in Dairy Heifers.CR (%)CR (%)Experimental Groups(Source: Adapted from Kasimanickam et al., 2008)with new (59.7%) vs 5-day usedCIDRs (61.2%). Obviously, correcthandling, sanitization, and evenautoclaving are important detailswhen re-utilizing CIDRs, mostly, toavoid horizontal spread of infectiousdiseases within the herd.The new 5-Day CIDR Synch mightalso be a good option for those whowant to use sexed semen associatedwith Timed A.I. in heifers. In fact,according to later findings (DCRC2009), the 5-Day CIDR protocolproduced acceptable conceptionresults even after the use of sexedsemen in heifers. For example, in oneof the trials that they used the 5-DayCIDR protocol with a single PGF2 αat CIDR removal, they found thatconception rates for dairy heifers bredwith sexed semen was 43% (43/100)compared to 53.1% (52/98) for heifersinseminated with regular semen. Thus,conception results with sexed semenin heifers treated with the 5-Day CIDRSynch are in the same range of theresults achieved when sexed semenis used after estrus detection, butfurther trials are necessary to confirmthese encouraging findings.In Summary, here are some of theadvantages of the 5-Day CIDR Synchprogram:1) No pre-synchronization is needed2) Minimum amount of handlings– very simple to apply.Experimental Groups(Source: Adapted from Thatcher et al., 2009 - DCRC)3) Consistent conception results andcomparable fertility to heat detectionbreedings, even in heifers.

insider4) The entire protocol lasts only 8days, which makes it an attractiveoption for re-synch breedings forheifers, as well as for beef and dairycows (future research needs tovalidate this for dairy cows).5) 5-Day CIDR synch providesacceptable results following sexedsemen breedings in heifers.REFERENCES:Decreasing the interval betweenthe GnRH and PGF2 αfrom 7 to 5 dand lengthening proestrus increasestimed-AI PR in beef cows. Bridgeset al., 2008. Theriogenology 69:843-851.Effect of reducing the period of follicledominance in a timed AI protocol onreproduction of dairy cows. Chebel.,et al. 2009. Proceedings ADSA-ASAS;pg. 250-251; Indianapolis, IN.Two doses of prostaglandin improvepregnancy rates to timed-AI in a 5-dprogesterone-based synchronizationprotocol in beef cows. Kasimanickamet al., 2009. Theriogenology 71:762-767.Timed AI programs in dairy heifers.Thatcher et al., 2009. ProceedingsDCRC; pg. 57-70; Minneapolis, MN.Fertility of Holstein dairy heifers aftersynchronization of ovulation and timedAI or AI after removed tail chalk. Riveraet al., 2004. J. Dairy Sci. 87:2051-2061.Accelerated Genetics • 800.451.9275 • 608.356.8357 • info@accelgen.com • www.accelgen.comPRSRT STDU.S. POSTAGEPAIDMADISON, WIPERMIT NO. 1949E10890 Penny Lane. Baraboo, WI 53913-9408Address Service Requestedinsider