Presentation on theme: "NEW OPPORTUNITIES TO SYNCHRONIZE ESTRUS AND FACILITATE FIXED-TIME AI"— Presentation transcript:
1NEW OPPORTUNITIES TO SYNCHRONIZE ESTRUS AND FACILITATE FIXED-TIME AI DJ Patterson, MF Smith, and DJ SchaferDivision of Animal SciencesUniversity of Missouri-ColumbiaJuly 6, 2005
2reproductive technology in the U.S. beef cattle industry…… The current status ofreproductive technology in the U.S.beef cattle industry……
3Reproductive Technologies Available or on the Horizon Estrus synchronization and AIUltrasonographySexed semenEmbryo transferIn vitro production of embryosTransgenics (pharming)CloningMale fertility
4The U.S. Beef Herd69% of cow-calf enterprises are secondary income sources50% of producers report an established breeding season of specific duration34% of beef herds are routinely pregnancy checked10% of beef cattle enterprises utilize AI
5What’s happening in adoption of technology in the beef industry on a global basis?
6Total Domestic Sales of Beef Semen In the U.S. …...Total Domestic Sales of Beef Semen19801982198419861988199019941996199820001992Hough,, 2002
7Comparison of AI Use In Beef Cattle (U.S. vs. Brazil)
9Unless efforts are taken to implement change in the U. S Unless efforts are taken to implement change in the U.S. beef cattle industry, the products of our research and technology may be exported to more competitive international markets (Patterson et al., 2000).
13Improvements in methods to synchronize estrus create the opportunity to significantly expand the use of AI in the U.S. cowherd ………………….
14A unique point in time for the U.S. beef industry……… Availability of tools and understanding of methods to control the estrous cycle in cattleA changing market structure that recognizes and rewards quality
15A unique point in time……… If we don’t impact use of AI among beef producers in the U.S. in the near future, will we ever?
16The challenge of transferring technology (estrus synchronization and AI) to the private sector exceeds the task of research and development of still newer technologies……….
17CollectivelyAdopt common terminology regarding the various estrus synchronization protocolsIdentify and agree upon short lists of protocolsheifers and cowsheat detect and AI vs fixed-time AIWork to overcome the attitude of “What will this cost me?” ….to… “ I’m willing to make an investment in my herd”
18Effective Estrus Synchronization Programs for Beef Cattle Facilitate AI & ETReduce time required to detect estrusCycling females conceive earlier in the breeding periodInduce cyclicity in peripubertal heifers and anestrous postpartum cows
19Objective: Development of highly effective & economical estrus synchronization programs Peripubertal heifersPostpartum cowsAnestrus and estrous cyclingExcellent pregnancy rates
20Products Currently Available ProstglandinLutalyse, Estrumate, ProstaMate, In Synch, EstroPlanGnRHCystorelin, Factrel, Fertagyl, OvaCystProgestinsMGACIDR
22Progesterone MGA (melengestrol acetate) Pregn-4-ene-3, 20-dione CH3MGA(melengestrol acetate)6-methyl-17-alpha-acetoxy-16-methylene-pregn-4, 6-diene-3, 20-dioneCOCH3CH2
23What We Know About MGA . . .Induces puberty in beef heifers (Imwalle et al., 1998)Prevents expression of behavioral estrus (Zimbelman and Smith, 1966; Imwalle et al., 2002)Blocks the preovulatory surge of LH (Imwalle et al., 2002)Blocks ovulation (Zimbelman and Smith, 1966; Imwalle et al., 2002)
25Reproductive Tract Scores (RTS) 45Length30> 32Height1620Width1215Ovarian Measurement (mm)Description Infantile Prepubertal PeripubertalCyclingUterine horns Immature < 20 mm diameter No tone mm diameter No tone mm diameter Slight tone 30 mm diameter good tone> 30 mm diameterOvarian StructuresNo palpable follicles8 mm follicles8-10 mm follicles> 10 mm folliclesCL possibleCL presentAdapted from Anderson et al., 1991
26Reproductive Tract Scores (RTS) Summary Pelvic Height (cm)13.9a14.1a14.5b14.7cPelvic Width (cm)10.9a11.2a11.4b11.7cPelvic Area (cm2)152a158a166b172cEstrous Response (%)54a66b76c83d86dWeight (lb)594a620b697c733d755dRTS12345n612781103494728a, b, c, d Numbers with different superscripts within a column differ (P < 0.05)Adapted from Patterson and Bullock, 1995
27Comparison of reproductive performance in herds using natural service or synchronization and AI on replacement heifers by RTSExposed21-d PR242-d PR3TPR4RTS1NS5(n)SAI6NS(%)SAI185538a42a63c55c63e60e210866131a52b54c68d75e82e3336332041a58b65c74d87f4322362948a62b72c77d91e5242283550a64b74c80d88eTOT10161050044a61b68c73d85e87ea,b Means within rows for 21-d PR with different superscripts differ (P < .05)c,d Means within rows for 42-d PR with different superscripts differ (P < .05)e,f Means Within rows for TPR with different superscripts differ (P < .05)From Randle and Patterson, 2005
28Synchronized Estrus estrus PG MGA (14 days) 1 14 16 20 31 33 36 Treatment daysBrown et al., 1988
29MGA-PG 14-19 d Improved estrous response Similar fertility More heifers in heatSimilar fertilityNo change in conception or pregnancy rateImproved synchronyMore heifers in heat in a shorter time(Deutscher et al., 2000; Lamb et al., 2000)
30PG MGA (14 days) MGA (14 days) PG GnRH MGA-PG 1 14 33 MGA Select Treatment daysMGA (14 days)1142633PGGnRHWood et al., 2001
31PG Follicle diameter (mm) Day of treatment ESTRUS Wood et al., 2001 5 5101520253035161718192122232426272829313233343637383940Day of treatmentFollicle diameter (mm)ESTRUSPGWood et al., 2001
32PG GnRH Follicle diameter (mm) Day of treatment Wood et al., 2001 5 10 5101520253035161718192122232426272829313233343637383940Day of treatmentFollicle diameter (mm)ESTRUSPGGnRHWood et al., 2001
33When to Add GnRH to an MGA-PG Protocol for Heifers Consideration ofAgeWeightReproductive tract score (RTS)Pubertal statusWood et al., 2000; Kojima et al., 2001
34How do MGA- and CIDR-based protocols compare in heifers?
35Experimental Protocols MGA SelectGnRHPGMGA (14 days)days days .. ..14-d CIDRGnRHPGCIDR (14 days)days days .. ..Treatment dayKojima et al., 2004
36Experimental Procedures 352 yearling crossbred beef heifers at three locations Location 1 n = 154 (Southeast Missouri) Location 2 n = 113 (North Dakota) Location 3 n = 85 (North central Missouri)Heifers were assigned to one of two treatments (MGA or CIDR) by age and weightKojima et al., 2004
37Summary for Timing of AI % of Heifers Inseminated 80CIDR (n = 177)MGA (n = 175)69%706053%50% of Heifers Inseminated403021%PG2015%16%10%10%105%0%1%12345+Days after PGNo treatment x location effect (P > 0.10); therefore, data were pooledDistribution of AI dates were different between MGA- and CIDR-treated heifers (P < 0.02)Kojima et al., 2004
38Estrous Response, AI Pregnancy, and Final Pregnancy Rates 154/177 (87 %)112/177 (63 %)a164/177 (93 %)CIDR147/175 (84 %)83/175 (47 %)b159/175 (91 %)MGA301/352 (86 %)195/352 (55 %)323/352 (92 %)Totala, b P = 0.01Diff.+ 3 %+ 16 %+ 2 %Kojima et al., 2004
39Summary In yearling beef heifers: CIDR-GnRH-PG improved synchrony of estrus compared with MGA SelectCIDR-GnRH-PG improved AI pregnancy rate over MGA SelectKojima et al., 2004
41How do MGA-based protocols perform in synchronizing estrus in mixed populations of postpartum beef cows? (estrous cycling and anestrus)
42Precise control of the bovine estrous cycle requires the synchronization of both luteal and follicular functions.
43Protocols MGA Select GnRH PG PG 7-11 Synch GnRH PG Treatment day MGA (14 days)PG7-11 SynchGnRHPGMGATreatment dayKojima et al., 2000; Wood et al., 2001
44These protocols were hypothesized to…… Improve estrous response and pregnancy rates during the synchronized periodEffectively synchronize estrus in estrous cycling cowsInduce cyclicity in anestrous cowsPrevent short cycles among anestrous cows induced to ovulate
45These protocols were hypothesized to…… Reduce the period of time required to detect estrusFacilitate fixed-time AI
46How do MGA Select and 7-11 Synch compare on the basis of synchronized estrus and pregnancy rates in postpartum beef cows with AI performed on the basis of detected estrus?
47MGA Select vs. 7-11 Synch AI performed after detected estrus No difference in estrous responseImprovement in synchrony of estrus among 7-11 Synch treated cows (P < 0.01)No difference in synchronized conception or pregnancy ratesNo difference in final pregnancy rateStegner et al., 2004
48Stegner et al., 2004 45 MGA Select 40 7-11 Synch 35 30 25 Cows in estrus, no20151051224364860728496108120132144NRTime after PG, hStegner et al., 2004
49Pregnancy Rates of Cows Inseminated after Detected Estrus No. (%)MGA SelectPatterson et al., /Patterson et al., /Stegner et al., /Combined total 195/7-11 SynchKojima et al., /Stegner et al., /Combined total 101/
50How do MGA Select and 7-11 Synch compare on the basis of pregnancy rates in postpartum beef cows inseminated at predetermined fixed times?
51MGA Select Time of AI after PG Pregnancy rate 48 hr 46% 72 hr 61% Stevenson et al., 200348 hr46%Perry et al., 200272 hr61%Stegner et al., 200372 hr80 hr64%50%
527-11 Synch Time of AI after PG Pregnancy rate 48 hr 72% 48 hr 60 hr Hixon et al., 200148 hr72%Kojima et al., 200348 hr60 hr52%59%Unpublished data., 200260 hr61%Kojima et al., 200260 hr63%Kojima et al., 200360 hr63%
53Bader et al. (2004) compared pregnancy rates resulting from fixed-time AI among suckled beef cows assigned to the MGA Select or 7-11 Synch protocols.
54Protocols AI MGA Select GnRH GnRH PG AI PG 7-11 Synch GnRH GnRH PG MGA (14 days)… … … 72 hrAIPG7-11 SynchGnRHGnRHPGMGA… … 60 hrTreatment dayBader et al., 2004
55Days postpartum, body condition score, and estrous-cycling status prior to initiation of synchronization treatmentsLocationDayspostpartumBodycondition scoreEstrous cyclingNo.%150 ± 1.0a5.8 ± 0.1a64/20831a239 ± 1.3b31/12225a,b336 ± 1.5b5.4 ± 0.1b18/9220bCombined42 d5.7113/42227a,b(P < 0.05)Bader et al., 2004
56Fixed-time AI and final pregnancy rates LocationTreatmentFixed-time AIFinalNo.%17-11 Synch64/1046295/10491MGA Select68/10465101/10497234/605757/5943/626960/62330/456743/459631/476642/4789Combined128/20961195/20894142/213203/21395Bader et al., 2004
57Fixed-time AI pregnancy rate based on pretreatment estrous cyclicity status MGA Select7-11 SynchCyclingAnestrusLocationNo. Preg%No Preg120/306748/746524/347140/7057212/167531/469/156025/455636/825/39648/108022/3563Combined38/5470104/15941/596987/15058Bader et al., 2004
58Pros and Cons Advantages Disadvantages MGA Select - effective in mixed treatment length populations MGA intake synchrony of estrus fertility after treatment Synch effective in mixed multiple populations animal handlings exceptional synchrony drug costs of estrus MGA intake fertility after treatment treatment duration
59Pregnancy rates after AI based on detected estrus or at predetermined fixed times No. (%)7-11 SynchDetected estrus 101/Fixed-time AI 446/MGA SelectDetected estrus 195/Fixed-time AI 281/
60ImplicationsThis sequential approach to estrous cycle control (progestin-GnRH-PG) effectively synchronizes estrus with resulting high fertility among mixed populations of estrous cycling and anestrous postpartum beef cows.
62How do MGA- and CIDR-based protocols compare on the basis of pregnancy rates in postpartum beef cows inseminated at predetermined fixed times?
63MGA Select vs. CO-Synch + CIDR Schafer, 2005 GnRHPGGnRHMGA (14 d)AI………GnRHPGGnRHCIDR (7 d)AI……….Treatment day
64Timing of Insemination Time of AI PregnancyProtocol after PG rateMGA SelectStevenson et al., h %Perry et al., h %Bader, h %Stegner et al., h %80 h %CO-Synch + CIDRLamb et al., h %48 h %Bremer et al., h %66 h %Larson et al., h %
65MGA Select vs. CO-Synch + CIDR Schafer, 2005 AIGnRHPGGnRHMGA (14 d)…… 72hAIGnRHPGGnRHCIDR (7 d)…... 66hTreatment day
66Experimental Procedures Schafer, 2005 Animals: Crossbred, suckled, beef cows (n = 650) at four locations were assigned to treatment within age groups by calving date and BCS
67Experimental Procedures Schafer, 2005 Four different AI sires were usedLocation 1 = 3Location 2 = 1Location 3 = 1Location 4 = 1One of the sires that was used at location 1 was the same sire used at Locations 3 & 4
68Experimental Procedures Schafer, 2005 Cows were exposed to fertile bulls 14 d after AIPregnancy rate to fixed-time AI was determined with ultrasound 40 – 45 d after insemination
69Number of cows at each location, DPP, BCS, and estrous-cycling status prior to initiation of synchronization treatments (Schafer, 2005)LocationDayspostpartumBodycondition scoreEstrous cyclingNo %1465.7112/210532336.063/158403445.331/8835443156/19480Combined42 d5.5362/65056
70Fixed-time AI pregnancy rates between treatments and among locations (Schafer, 2005) No.%1MGA Select70/10666CO-Synch+CIDR67/10464253/8056/7872326/455829/4367452/965462/9861
71Pregnancy rates to fixed-time AI Schafer, 2005 Treatment No %MGA Select /CO-Synch+CIDR /
72Fixed-time AI pregnancy rate based on pretreatment estrous cyclicity status (Schafer, 2005) MGA® SelectCO-Synch+CIDRCyclingAnestrusLocationNo. Preg%No Preg138/626132/447330/506037/5469220/2933/516525/347431/4470311/1615/29528/155321/2875441/7811/1850/786412/20Combined110/1855991/142113/177101/146
73Conclusions Schafer, 2005The results from this experiment demonstrate that comparable pregnancy rates to fixed-time AI can be achieved using the MGA Select or CO-Synch+CIDR protocols to synchronize estrus in postpartum beef cows.
74Do we know what to expect at calving from cows that conceive on the same day to the same sire?
75Days relative to 285 d gestation due date; Bader et al., 2004 510152025-13-12-11-10-9-8-7-6-5-4-3-2-11234678510152025-10-9-8-7-6-5-4-3-2-11234A; Angus; +6.2 BW, 20 dB; Angus; +3.3 BW, 17 d510152025-11-10-9-8-7-6-5-4-3-2-11234510152025-10-9-8-7-6-5-4-3-2-112346789C; Red Angus; –1.5 BW, 2 CED, 15 dD; Simmental; -0.6 BW, CE, 19 d25B; Angus; +3.3 BW, 17 d20% of AI calves born15105-11-10-9-8-7-6-5-4-3-2-1123456Days relative to 285 d gestation due date; Bader et al., 2004
76Location 1; Sire A (Angus) BW EPD -0 Location 1; Sire A (Angus) BW EPD -0.3; CED = +11 Range Mean = 281Location 1; Sire B (Angus) BW EPD +3.5; CED = +6 Range Mean = 281Location 1; Sire C (Angus) BW EPD -1.1; CED = +11 Range Mean = 281Location 2; Sire D (Red Angus) BW EPD +2.3; CED = -2 Range Mean = 283Location 3; Sire B (Angus) BW EPD +3.5; CED = +6 Range Mean = 283Location 4; Sire B (Angus) BW EPD +3.5; CED = +6 Range Mean = 284
77Calving Distribution of AI sired calves (Schafer et al., 2005)
78Consider the impact of estrus synchronization on calving distribution………
79Hughes, 2005Opportunities for increasing profits lie in managing females from the later calving intervals forward toward the first and second calving intervals.High production herds see 61% of the calves born by day 21, 85% by day 42 and 94% by day 63.
80Stegner et al., 2004 100 MGA Select 90 7-11 Synch 80 70 Cows calving, %605040302010First 15 dFirst 30 dCalving periodStegner et al., 2004
85Treatment Estrous response Pregnancy rate AI based on Estrous response and fertility in postpartum beef cows after treatment with various estrus synchronization protocols.Treatment Estrous response Pregnancy rateAI based ondetected estrus No % No %2 shot PGSelect Synch*MGA-PGMGA Select7-11 Synch241/353/305/275/142/147/237/220/195/101/Fixed-time AIMGA Select7-11 SynchCO-Synch + CIDR482/446/214/* DeJarnette and Wallace
86Treatment Estrous response Pregnancy rate Estrous response and fertility in postpartum beef cows after treatment with various estrus synchronization protocols.Treatment Estrous response Pregnancy rateAI based on detected estrus No % No %2 shot PGSelect Synch*MGA-PGMGA Select7-11 Synch241/353/305/275/142/147/237/220/195/101/Fixed-time AIMGA Select7-11 SynchCO-Synch + CIDR482/446/214/* DeJarnette and Wallace
88Research is underway to develop new protocols for heifers that will facilitate fixed-time AI …. The technology now exists to successfully inseminate postpartum beef cows at predetermined fixed times with resulting high pregnancy rates
89Improvements in methods to synchronize estrus create the opportunity to significantly expand the use of AI in the U.S. cowherd
90Acknowledgements Faculty, Students, & Staff Jon Bader Dr. George PerryRoger Eakins Daniel SchaferDr. Mark Ellersieck Jon SchrefflerFreddie Kojima Dr. Mike SmithDr. Matthew Lucy Jacob StegnerDavid McAtee Stacey Wood (Follis)
91Acknowledgements Research Support Cooperators Select Sires, Inc. 4-M RanchKABA/Select Sires, Inc. John RanchABS Global Jim Wallis FarmsMerial Jim Clement, DVMPfizer Animal Health SEMO UniversityUSDA-NRI MFA, Inc.MU Farms & Centers
92Acknowledgements Beef Reproduction Leadership Team AI industry Pharmaceutical industryVeterinary practitionersNorth Central Region Bovine Reproduction Task Force