Estrus and ovulation synchronization in beef heifers Dr. Marcos G Colazo Research Scientist, Alberta Agriculture & Rural Development Edmonton, Alberta, Canada E-mail: marcos.colazo@gov.ab.ca; mgcolazo@yahoo.com
Outline of talk Estrous cycle of the heifer What is CR and PR? Controlling the estrous cycle Synchronization of estrus Synchronization of ovulation Protocols Advantages and disadvantages Cost
Estrous cycle of the heifers Average 21 days long (18 to 24) Two phases luteal and follicular Four stages Proestrus (Day 18-20) Estrus (Day 0) Metestrus (Day 1-3) Diestrus (Day 4-17)
Pregnancy Rate (PR) = Estrus Detection Efficiency (EDE) x Conception rate (CR)
n EDE CR PR (%) (%) (%) 100 50 50 25 100 80 50 40 100 100 50 50
Controlling the estrous cycle Shortening the luteal phase Simulating the luteal phase Controlled follicle growth & ovulation (e.g.) ProstaglandinF2 (e.g.) Progesterone (e.g.) Estrogens & GnRH
Commercially available PGF products
Follicle size (mm) Active CL, D 5-16 20 Growing CL PGF effective Regressing CL 15 10 Ov Ov 5 0 7 14 21 Day of cycle Metestrus Diestrus Pro estrus Estrus
Common Protocols using PGF Estrus detection and AI Estrus detection and AI EDR~80% 6 days PGF Estrus detection and AI EDR~85% PGF 11 days PGF Estrus detection and AI PGF 14 days PGF EDR~85%
% in heat Distribution of heat in beef heifers given PGF 11 d apart 60 50 40 30 20 10 0 24 36 48 60 72 84 96 Hours after second PGF Total in heat: 84% Butler et al., 2001
% in heat Distribution of heat in Holstein heifers given PGF 14 d apart 60 50 40 30 20 10 0 36 48 60 72 84 96 108 120 132 144 Hours after second PGF n = 132 Total in heat: 86% Colazo, unpublished
% P r e g n a n t 100 90 80 70 60 50 40 30 20 10 0 Conception Rate a b 80.9% 60.0% 14 d apart PGF 5d Modified Cosynch ~half AI with sexed semen a, b Effect of TRT P < 0.05
Controlling the estrous cycle Shortening the luteal phase Simulating the luteal phase Controlled follicle growth & ovulation (e.g.) ProstaglandinF2 (e.g.) Progesterone (e.g.) Estrogens & GnRH
Oral Progestins: Melengestrol Acetate (MGA) Ear implants Crestar Intravaginal Devices PRID CIDR-B DIB TRIU-B CUE-MATE
Program with MGA for estrus synchronization MGA Day 0 14 (17/19 days) PGF 31/33 ED + AI NO AI MGA = melengestrol acetate @ 0.5 mg/heifer/day
Modified MGA program (MGA select) MGA Day 0 14 GnRH 26 PGF 33 ED + AI NO AI Wood-Follis et al., 2004
MGA/PGF vs. MGA Select (ED + AI for 6 days) Anestrus Cycling 100 90 80 70 60 50 40 30 20 10 0 80 93 80 96 MGA/PGF MGA select 90 80 70 60 50 40 30 20 10 0 * * 66 67 63 82 MGA/PGF MGA select Estrus rate Pregnancy rate N = 124 Wood-Follis et al., 2004
Increase estrus detection rate Aggressive estrus detection Increased frequency of observation Use of estrus-detection aids Tail paint, Kamar, electronic aids
Controlling the estrous cycle Shortening the luteal phase Simulating the luteal phase Controlled follicle growth & ovulation (e.g.) ProstaglandinF2 (e.g.) Progesterone (e.g.) Estrogens & GnRH We used them in combination for TAI
17 Plasma concentrations Benzoate Valerate Cipionate 1 2 3 4 5 6 7 8 9 Days after treatment
TAI protocol (Progesterone & Estrogen) DAY 0 7 9 10 Insert CIDR Give 1 or mg EB o 5 mg E-17B Remove CIDR Give PGF 1 mg EB TAI
TAI protocol-schedule (Progesterone & Estrogen) MON am TUE am WED pm THU FRI SAT SUN EB or 17B CIDRi CIDRr EB TAI PGF
Pregnancy rate in heifers treated with E17B or EB % 100 90 80 70 60 50 40 30 20 10 0 65 E17B 56 Cyclic Acyclic 59 BE 46 n = 1428 heifers Colazo unpublished
TAI protocol (Progesterone & Estrogen) DAY 0 7 9 10 Insert CIDR Give 5 mg E-17B Remove CIDR Give PGF 0.5 mg ECP TAI
PREGNANCY RATES 80 70 60 50 40 30 20 10 0 63.3 64.6 63.1 ECP0 (n=98) ECP24 (n=99) EB24 (n=103) Colazo et al., 2003
Pregnancy rate for cattle inseminated 24 versus 36 h after second EB treatment 80 70 60 50 40 30 20 10 0 49.1 69.8 24 h (n=57) 36 h (n=53) Colazo et al., 2005
Some commercially available GnRH products Fertiline (Vetoquinol) Cystorelin (Merial) Factrel (Pfizer Animal Health) Fertagyl (Merck Animal Health)
How Ovsynch works? D 0 D 7 D 9 D 10 GnRH PGF GnRH AI 7 d 2 d 16 h Induced ovulation New follicle growth CL regression and Follicle maturation Synchronized Ovulation Pursley et al., 1995
Cosynch Second GnRH given at time of AI D 0 D 7 D 9 GnRH PGF GnRH D 10 GnRH + AI 7 d 2 d 0-12 h Advantage: Reduced handling Possible disadvantage: Delayed ovulation
Pregnancy Rates (%) 60 50 40 30 20 10 0 54% 52% n = 360 n = 392 Cosynch Ovsynch Geary et al., 2001
Pregnancy rates to AI in cows and heifers after estrus or Ovsynch IDE% OVS/TAI% P Cows 39 (154) 38 (156) >.10 Heifers 74 (78) 35 (77) <.01 P <.01 >.10 Ovsynch/Timed AI is not effective in heifers Pursley et al. (1997) JDS 80:295
Cosynch plus CIDR or PRID D 0 D 7 D 10 GnRH PGF GnRH&AI CIDR or PRID 56-60 h In D 0 Out D 7
Pregnancy rate Category Cosynch CIDR+Cosynch Cows n = 71 n = 77 45.1% 42.9% Heifers n = 23 n = 25 39.1% a 68.0% b ab (P<0.05). Martinez et al., 2002
TAI protocol-schedule (7d Cosynch & CIDR) MON am TUE am WED pm THU FRI SAT SUN GnRH CIDRi CIDRr PGF GnRH & TAI
Experimental Design - 5 d vs 7 d Cosynch GnRH PGF 2α 7 d CIDR 60 h d -7 d -5 d 0 d 0 GnRH + AI 5 d CIDR 72 h GnRH PGF 2α Day et al., 2006
Pregnancy Rate, % Timed AI Pregnancy Rate 5 d vs 7 d Cosynch 80 70 60 50 40 30 20 10 0 7-d CIDR 5-d CIDR 53% 73% 58% 61% 56% 65% Jackson Belle Valley Overall (n=150) (n=250) (n=400) Trt, P<.03; TrtxLoc, P=.08 Day et al., 2006
TAI Pregnancy Rate % P r e g n a n t 100 90 80 70 60 50 40 30 20 10 0 a b CO-Synch 5d CIDR CO-Synch 7d CIDR 120/201 100/204 a, b Effect of TRT P < 0.03
Experimental Design Modified 5 d Cosynch d -5 d 0 5 d PRID GnRH PGF 2α d -5 d 0 5 d PRID 72 h GnRH + AI PGF 2α Colazo and Ambrose, 2011
Pregnancy Rate, % Timed-AI Pregnancy Rate 90 80 70 60 50 40 30 20 10 0 5-d Cosynch PRID 5-d Modified Cosynch PRID n=28 n=28 Treatment Trt, P >0.05 Colazo and Ambrose, 2011
TAI protocol-schedule (5d Cosynch & PRID) MON am TUE am WED am THU am FRI SAT SUN GnRH PRIDi PRIDr PGF PGF GnRH & TAI
Timed-AI programs: Overall results Studies published between 2000 and 2006 Treated beef heifers: 3109 GENMOD en SAS Pregnancy rate: 53.9 % Range: 47,3 % to 70,0 %
Timed-AI programs (Cycling vs. anestrus) 70 60 50 56* 49 40 30 26% 20 10 0 Cyclic Acyclic P < 0.01 n = 3110 heifers
No. of calvings Calving distribution of 90 beef heifers all bred on a single day 14 12 10 8 6 4 2 0 270 272 274 276 278 280 282 284 286 Gestation length (days) N = 90 Reuter and Rinette, 2009
Resynchronization of timed inseminated heifers with a used CIDR or MGA and E/P Groups CIDR MGA Control CIDR +E/P +E/P/E MGA +E/P +E/P/E Preg. to 1 st AI (%) 45.2 ab 47.3 a 49.5 a 33.3 b 54.8 a 45.2 ab 48.4 a 42 44 46 31 51 42 45 Estrus rate (%) 88.2 ac 91.8 ab 95.7 a 95.2 a 83.3 bc 84.3 c 77.1 c n 45/51 45/49 45/47 59/62 35/42 43/51 37/48 Conception rate (%) 62.2 ab 64.4 ab 73.3 a 59.3 b 40.0 c 53.5 bc 54.0 bc n 28/45 29/45 33/45 35/59 14/35 23/43 20/37 Pregnancy rate (%) 54.9 ab 59.2 ab 70.2 a 56.4 ab 33.3 c 45.1 bc 41.7 bc n 28/51 29/49 33/47 35/62 14/42 23/51 20/48 TAI & Rebreeding 75.3 ab 78.5 ab 84.9 ac 71 b 69.9 b 69.9 b 69.9 b abcd Percentages are different (P<0.05)
Resynchronization of heifers with a used CIDR (12,13 or 14 d after AI) 983 beef heifers TAI over 3 days All received a used CIDR device 336 heifers reinseminated over 5 days (78.2%) 542 pregnant to TAI (55.2%) and 232 pregnant to re-insemination Overall PR of 78.7%
Timed-AI programs: Cost per pregnancy based on 100 heifers CIDR/EB CIDR/OVS CIDR/COS7 CIDR/COS5 CIDR/COSM5 Drugs Labour Semen + AI PR Per Preg $ 26.5 $ 30.0 $ 30.0 $ 35.0 $ 26.5 $ 300 $ 300 $ 240 $ 300 $ 240 $ 2500 $ 2500 $ 2500 $ 2500 $ 2500 65% 55% 50% 65% 60% $ 83.8 $ 105.5 $ 114.8 $ 96.9 $ 89.8
May, 2004
THANK YOU! Marcos G Colazo Research Scientist, Alberta Agriculture & Rural Development Edmonton, Alberta, Canada E-mail: marcos.colazo@gov.ab.ca; mgcolazo@yahoo.com