Jeffrey S. Stevenson, Ph.D. Department of Animal Sciences and Industry Improving Pregnancy Rates Ontario Association of Bovine Practitioners Reproductive Symposium

Objective Maximize number of pregnancies achieved each week! PR = Submission Rate × Conception Rate Example: 15% Herd #1: PR = 50% SR × 30% CR = 15% 21% Herd #2: PR = 70% SR × 30% CR = 21%

Pregnancy Rate Factors Submission rates Heat detection TAI programs for first services Frequency of “open” checks Resynchrony of repeat services Conception rates Proper handling and placement of semen Dry matter intake Cycling status Energy balance Feed supplements Use of rbST Use of Presynch Length of VWP Herd health programs Sire fertility

Increasing Submission Rates Heat detection TAI programs for first services Frequency of “open” checks Resynchrony of repeat services Increasing submission rates...

Fertile egg life Ovulation Standing heat 0 27 h  20 4040 Secondary heat signs Normal fertile sperm life Correct Timing of AI AI Increasing submission rates...

Source: Hurnik et al. (1975) Appl. Anim. Ethol. 2:55 Standing Activity is a Function of the Number of Cows in Estrus  More mounted cows (90%) are in estrus than mounting ones (79%)  Standing events ranged from 1 to 179  Inclination to mount is stage-of-cycle dependent Increasing submission rates... Hurnik et al., 1975

Source: Helmer and Britt (1985) JDS 68:1290 Stage of Cycle and Mounting Activity Increasing submission rates...

Housing and Footing  Maximize the number of nonpregnant cows housed together to increase heat detection efficiency  During estrus cows prefer to spend 73% of their time on dirt than on concrete  Mounting activity increases 3-15 fold when cows are on dirt  Duration of estrus and standing activity is greater for cows on dirt Britt et al., 1986 Increasing submission rates...

Ovsynch Protocol GnRH PGF 2  7 days 48 h GnRH CL(s) regresses 0 – 24 h TAI LH surge ovulates Dominant follicle Ovulation h ovulates Dominant follicle Increasing submission rates...

GnRH + PGF 2  + Heat Detection (Control) vs. Ovsynch during Summer Increasing submission rates... Cartmill et al., 2001

Transrectal palpation* Transrectal ultrasound* FrequencyRangeMissed AIRangeMissed AI Monthly35 to 651 to 328 to 581 to 2 Biweekly35 to 481 to 228 to 411 Weekly35 to 411 to 228 to 341 Frequency of Pregnancy Checks *Assumes palpation begins at 35 days and ultrasound at 28 days of pregnancy, respectively. Increasing submission rates...

Pregnancy Check GnRH AI PGF M M W Th 7 days GnRH Rebreeding Options AI Concentrated heat detection days after AI Applying Ovsynch to Open Cows Heat Checks Increasing submission rates...

Pregnancy Check GnRH AI PGF M M W Th 7 days GnRH Rebreeding Options AI Starting Ovsynch 7 days before Preg Checks Heat Checks Concentrated heat detection days after AI Increasing submission rates...

Pregnancy diagnosis by ultrasonography Cosynch TAI 0 Day GnRH TAI PGF Resynch before Pregnancy Diagnosis Fricke et al., Day Day Day 19 Day 2642% a (n = 240) 34% b (n = 121) Day 3333% b (n = 236) 38% b (n = 143) 46% a (n = 235) 23% a (n = 120) Trt1st TAI2nd TAI (n=711) Increasing submission rates...

GnRH TAI PGF GnRH AI PGF GnRH + AI PGF GnRH W W M M Th M M W Th Presynch + Ovsynch Ovsynch Days after AI* Pregnancy diagnosis M M W Th Heat checks All cows Open cows 14 days 12 days 7 days etc. 3 days 7 days AI Breeding with No Heat Detection or

Increasing Conception Rates Proper handling and placement of semen Dry matter intake Cycling status Energy balance Length of VWP Herd health programs Sire fertility

Handling Semen  Semen handling: Cold shock?  Thaw too many straws at one time?  Cleanliness of AI equipment  Fatigue: Too many cows to AI at one time?  Semen placement Increasing conception rates...

Conception Rates after First AI at Various Postpartum Intervals Britt, 1975 (8 studies)

n= DIM n= DIM n= DIM 2-yr-olds Older cows Milk yield (lb) at 35 DIM Tenhagen et al. (2003) Milk Yield Groups Increasing conception rates...

n = 148 Tenhagen et al. (2003) Low-Producing Cows n = yr-olds: <55 lb/day Older cows: <71 lb/day Days in Milk at Ovsynch Timed AI *P < 0.05 * Increasing conception rates...

n = 128 Days in Milk at Ovsynch Timed AI Tenhagen et al. (2003) High-Producing Cows n = yr-olds: >66 lb/day Older cows: >88 lb/day *P < 0.05 * Increasing conception rates...

Sire Fertility Estimated Relative Conception Rate (ERCR) –Ranking of sires relative to other sires (herds in midwest, east, and south U.S.) –Based on 70-day non-return rate –Ranges from –5 to +4 for Holsteins and –7 to +4 for Jerseys (May, 2004) –Go to Click on “Bull Fertility Summary” –Generally accurate ranking of sire fertility Increasing conception rates...

Sire Fertility AgriTech Analytics (5545 Avenida de los Robles, Visalia, CA 93291; tel: or ; fax: ) –Ranking of sires relative to other sires (herds in western U.S. only). Based on actual pregnancy diagnoses –Ranges from –9 to +6 for Holsteins (April, 2004). Data for Jerseys are available (5-star system) Most accurate ranking of actual sire fertility Available for a nominal fee to any dairy producer Increasing conception rates...

AI 4 to 9 days post-AI Pregnancy diagnosis hCG (3.3 mL of Chorulon) GnRH (2 mL of Fertagyl) Control 11 to 16 days post-AI 24 to 47 days post-AI 38 to 78 days post-AI CIDR AI Experimental Design

Percentage of Cows with Induced CL (Exp. 1) * *Different from control (P < 0.001) * n = 41 n = 40 Stevenson et al. (2006)

* n = 190 n = 182 n = 194 n = 187 Change in Concentrations of Progesterone in Serum (Exp. 1) *Different from control (P < 0.001) Stevenson et al. (2006)

Conception Rates after Post-AI Treatments of P4 (CIDR insert), GnRH, and hCG (Exp. 2) Treatment HerdControlCIDRGnRHhCG % (no. of cows) (41)50.1 † (40)32.6 (40)38.7 (38) (158)30.8 (158)28.6 (159)34.0 (158) (143)40.3** (162)31.3 (153)37.8* (153) (206)23.4* (204)29.8 (209)33.7 (209) (160)22.3 (147)20.2 (158)25.6 (156) Total (708) 32.7 † (711) 28.1 (719)33.6* (714) †Different from control (P < 0.10; *P < 0.05; **P < 0.01). 1 A tendency (P = 0.11) for a treatment × herd interaction. Stevenson et al. (2006)

n = 36 n = 216 n = 695 n = 843 n = 1,017 n = 45 Conception Rates by Day of Treatment (Exp. 2) Treatment (Exp. 2) Stevenson et al. (2006)

The bottom line is the number of pregnancies produced per unit of time. The bottom line ….. is the number of pregnancies produced per unit of time. How does one measure the success of the AI- breeding program?

No. of Services and Pregnancies Number Week of year Weekly Preg. Goal

Thank you! Department of Animal Sciences and Industry Ontario Association of Bovine Practitioners Reproductive Symposium