Using estrus-detection patches to optimally time artificial insemination (AI) and improve pregnancy rates in suckled beef cows in a timed AI program

Using estrus-detection patches to optimally time artificial insemination (AI) and improve pregnancy rates in suckled beef cows in a timed AI program Hill, S. L., D. M. Grieger, K. C. Olson, J. R. Jaeger, C. R. Dahlen, S. R. Underdahl, G. A. Bridges, J. E. Larson, J. K. Ahola, M. C. Fischer, G. A. Perry, T. L. Steckler, W. D. Whittier, J. F. Currin, and J. S. Stevenson

THE BULL YOU WANTED Production Carcass CED BW WW Milk YW SC Marb RE Fat Incredibull +33-5.0 +80 +50 +150 +2.0 +1.11 +1.50 -.56

THE BULL YOUR SPOUSE WANTED Production Carcass CED BW WW Milk YW SC Marb RE Fat Compatabull +23-3.0 +60 +40 +110 +1.0 +.95 +1.00 -.36

THE BULL THE AUCTIONEER WANTED YOU TO BUY Production Carcass CED BW WW Milk YW SC Marb RE Fat Capibull +13-1.0 +50 +20 +100 +.50 +.65 +.50 -.16

THE BULL YOU BOUGHT Production Carcass CED BW WW Milk YW SC Marb RE Fat Terrabull +0 -.0 +0 +0 +00 +.00 +.00 +.00 -.00

THE BULL YOU SHOULD HAVE BOUGHT

Insemination by Appointment (FTAI) Effective Efficient Labor saving Best fit

Time to estrus 100 Hours 80 60 40 62.3 76.7 62.9 20 0 6 to 9 10 to 13 14 to 18 Day of estrous cycle Floyd et al., 2014

Busch et al., 2008

Hypothesis: The proportion of cows becoming pregnant from timed AI will be greater when two compared with one insemination time are employed after use of estrus-detection patches to identify estrus

Patch evaluation* TAI + GnRH -2 Estrus (+) control (*activated patch) GnRH-1 TAI + GnRH-2 Nonestrus ( ) control Early-Early (E-E) (*nonactivated patch) 17 BS 7 BS CIDR GnRH-2 TAI Early-Delayed (E-D) (*nonactivated patch) TAI + GnRH-2 0 60 h 75 h Delayed-Delayed (D-D) (*nonactivated patch)

Characteristics of Experimental Units Location No. of cows BCS Days postpartum at AI Parity Cycling status 1 (%) CO 93 5.8 ± 0.7 73.7 ± 16.5 4.1 ± 2.8 * IL 150 5.2 ± 0.7 67.0 ± 12.6 5.6 ± 2.6 * KS-1 179 5.7 ± 0.5 92.9 ± 14.4 4.0 ± 2.4 96 KS-2 57 6.9 ± 0.8 67.4 ± 21.6 2.3 ± 0.5 74 KS-3 65 4.8 ± 0.5 75.1 ± 13.7 4.6 ± 2.3 66 KS-4 51 4.5 ± 0.4 65.1 ± 15.3 4.3 ± 2.6 59 KS-5 29 6.8 ± 0.6 60.6 ± 22.5 2.2 ± 0.4 59 KS-6 18 6.4 ± 0.6 73.8 ± 16.7 5.7 ± 2.1 44 MN 125 4.9 ± 0.7 69.8 ± 25.8 2.5 ± 0.7 61 MS 50 5.4 ± 0.5 67.4 ± 19.5 4.2 ± 2.3 * ND 174 5.4 ± 0.6 70.9 ± 11.8 3.8 ± 2.7 * SD 102 5.6 ± 0.4 81.5 ± 15.3 3.3 ± 2.6 32 VA-1 214 4.5 ± 0.9 78.6 ± 20.2 4.9 ± 3.3 63 VA-2 218 4.2 ± 0.6 75.2 ± 17.8 4.8 ± 3.1 52 Total 1,524 5.1 75.1 4.2 61 1 Cycling determined by serum progesterone concentration before CO-Synch + CIDR program was initiated.*locations with no blood collection.

Estrus expression by location Location Estrus by 60 h Estrus by 75 h N CO 40.9 67.7 93 IL 53.3 74.7 150 KS-1 38.2 64.0 178 KS-2 68.4 94.7 57 KS-3 49.2 55.4 65 KS-4 55.1 77.6 49 KS-5 51.7 82.8 29 KS-6 77.8 88.9 18 MN 48.0 68.0 125 MS 32.0 68.0 50 ND 57.5 80.9 174 SD 58.8 81.4 102 VA-1 30.3 61.6 211 VA-2 34.9 78.4 218 Total 45.6 72.6 1519

Estrus expression by prior cycling status % 100 90 80 70 60 50 40 30 20 10 0 a Cycling b Anestrus 60h estrus 75h estrus a, b : p<0.05

Estrus at 75h by Treatment Estrus (%) 100 90 80 70 60 50 40 30 20 10 0 a 49.0 50.0 Early GnRH - Early TAI Early GnRH - Delayed TAI 56.9 280 270 281 b Delayed GnRH - Delayed TAI LS means a,b tend to differ p=0.10

Pregnancy Rate by Estrus and Treatment (n) In heat by 75 h Estrus EE ED DD Total NO 44.0 (109) 46.0% (100) 38.9% (90) 43.1% (299) YES 68.9% (591) 53.5% (101) 71.1% (97) 69.8% (116) 67.5% (905) Total 68.9% (591) 48.6% (210) 58.4% (197) 56.3% (206) 61.4% (1204)

90% 80% 70% 60% 50% 40% 30% 20% 10% 0% Pregnancy by location

Pregnancy at 35d by treatment 70 65.9 a Pregnancy per AI (%) 60 50 40 30 44.0 c b 54.6 53.0 b 20 10 689 281 270 279 0 Estrus Early GnRH - Early TAI Early GnRH - Delayed TAI Delayed GnRH - Delayed TAI a, b, c : p<0.05

STAI vs FTAI models Single Fixed AI time at 60h Estrus + 3(EE) = all cows bred at 60h 60h: 825/1531 = 53.9% Split timing of AI at 60 and 75h Estrus + 3(ED) = estrus cows bred at 60h, non-estrus cows at 75h 60h and 75h: 915/1531 = 59.7%

Cost-benefit associated with Split-TAI compared with Fixed -TAI Expenses /unit cost Units Additional Pregnancies Item Total Sub Total Heat Patches 1.3 100 130 Handling Labor 1.5 55 82.5 Facilities 1.8 55 99 311.5 Income 42 # age 2 42 5.8 487.2 20 # genetic 2 20 5.8 232 calving int 2 21 5.8 243.6 AI labor 0 0 5.8 0 Bull Cost 66 1 5.8 382.8 1345.6 Net 1034.1

Summary More cycling cows express estrus by 75h 73% of cows expressed estrus by 75h 65% of cows showing estrus by 75h were pregnant to AI at 35d Timing AI at 75h as compared to 60h increased pregnancies/ai in cows not showing estrus at 60h

Future direction Continue to explore timing options Examine the necessity of GnRH in estrus cows Consider options to simplify treatments

Questions?