Jeffrey S. Stevenson, Ph.D .

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

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

3. 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 Pregnancy Rate Factors

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

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

6. Increasing submission rates . . . 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 Hurnik et al., 1975 Source: Hurnik et al. (1975) Appl. Anim. Ethol. 2:55

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

8. 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 • Durationof estrus and standing activity isgreater for cows on dirt Britt et al., 1986

9. Ovulation Dominant follicle ovulates Increasing submission rates . . . Ovsynch Protocol GnRH GnRH TAI PGF2 7 days 48 h 0 – 24 h 24-34 h CL(s) LH surge Dominant regresses follicle ovulates

10. Increasing submission rates . . . GnRH + PGF2 + Heat Detection (Control) vs. Ovsynch during Summer Cartmill et al., 2001

11. Increasing submission rates . . . Frequency of Pregnancy Checks *Assumes palpation begins at 35 days and ultrasound at 28 days of pregnancy, respectively.

12. Heat Checks Increasing submission rates . . . Rebreeding Options Applying Ovsynch to Open Cows Pregnancy Check GnRH PGF GnRH AI AI 7 days M M W Th Concentrated heat detection 21-25 days after AI

13. Heat Checks Increasing submission rates . . . Rebreeding Options Starting Ovsynch 7 days before Preg Checks Pregnancy Check GnRH PGF GnRH AI AI 7 days M M W Th Concentrated heat detection 21-25 days after AI

14. Increasing submission rates . . . Resynch before Pregnancy Diagnosis Pregnancy diagnosis by ultrasonography Cosynch TAI GnRH GnRH PGF TAI 0 Day 19 26 28 29 (n=711) 0 Day 26 33 35 36 0 Day 33 40 42 43 Trt 1st TAI 2nd TAI Day 19 46%a (n = 235) 23%a (n = 120) Day 26 42%a (n = 240) 34%b (n = 121) Day 33 33%b (n = 236) 38%b (n = 143) Fricke et al., 2003

15. GnRH PGF PGF PGF GnRH + AI Presynch + Ovsynch 7 days 14 days 3 days 12 days W W M M Th AI Breeding with No Heat Detection GnRH or PGF GnRH AI 7 days Ovsynch M M W Th Pregnancy diagnosis All cows Open cows GnRH PGF TAI GnRH Heat checks 7 days etc. 20 25 33 40 42 43 Days after AI* M M W Th

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

17. Increasing conception rates . . . 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

18. Conception Rates after First AIat Various Postpartum Intervals Britt, 1975 (8 studies)

19. Increasing conception rates . . . Milk Yield Groups n=148 73-81 DIM n=262 73-81 DIM n=142 73-81 DIM 2-yr-olds <55 55-66 >66 Older cows <71 71-88 >88 Milk yield (lb) at 35 DIM Tenhagen et al. (2003)

20. 2-yr-olds: <55 lb/day Older cows: <71 lb/day Increasing conception rates . . . Low-Producing Cows * n = 153 n = 148 *P < 0.05 Days in Milk at Ovsynch Timed AI Tenhagen et al. (2003)

21. 2-yr-olds: >66 lb/day Older cows: >88 lb/day Increasing conception rates . . . High-Producing Cows * n = 142 n = 128 *P < 0.05 Days in Milk at Ovsynch Timed AI Tenhagen et al. (2003)

22. 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 http://www.drms.org/ Click on “Bull Fertility Summary” Generally accurate ranking of sire fertility Increasing conception rates . . . Sire Fertility

23. AgriTech Analytics(5545 Avenida de los Robles, Visalia, CA 93291; tel: 800-532-0900 or 559-738-5300; fax: 559-738-5321) 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 . . . Sire Fertility

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

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

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

27. Conception Rates after Post-AI Treatments of P4 (CIDR insert), GnRH, and hCG (Exp. 2) †Different from control (P < 0.10; *P < 0.05; **P < 0.01). 1A tendency (P = 0.11) for a treatment × herd interaction. Stevenson et al. (2006)

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

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

30. No. of Services and Pregnancies Number WeeklyPreg. Goal Week of year

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