Fertility in Beef Cattle

Transcription

1 Fertility in Beef Cattle Tom Geary Reproductive Physiologist

2 Pregnancy Diagnosis Cow Fertility Breeding Season Vibrio Trich Stress Bull Fertility BVD Plant / Water Toxins Neospora EBA (Foothills) Nitrates IBR Lepto Mycotoxins Pine Needle Calving Season When?

3 Factors affecting Individual Pregnancy Cow Fertility Postpartum interval (PPI) Age Body Condition Score (BCS) Genetics Dystocia Nutrition Bull Fertility Stress Disease Toxins

4 Percentage of Calves Born Calving Distribution Management A B C D Day of Calving Season Ranch C Ranch B Ranch D Ranch A Shorter calving season improves ability to manage cattle in your environment & increase profitability of cowherd!

5 Nutrient Partitioning 1. Maintenance 2. Activity 3. Growth 4. Milk production 5. Body reserves (FAT) 6. Reproduction Proper nutrition is obligatory to reproductive success, but not focus of presentation.

6 Improve Cowherd Reproduction with Genetics Crossbreeding!!!

7 Crossbreeding Breed A Breed B Animal Breeding 101 Reproduction Production Carcass Additive genetic value Selection Non-additive genetic value Hybrid Vigor

8 Cumulative hybrid vigor effects on weight of calf weaned per cow exposed % Increase Combined Effects of: Reproduction Survival Maternal Ability 8.5 Age of Puberty Straightbred calves from straightbred cows X-bred calves from straightbred cows X-bred calves from x- bred cows Cundiff et al., 1974; Hereford, Angus, & Shorthorn

9 AI Heifers to Calving Ease Proven Sires At today s diesel prices, maybe I should consider AI.

10 Cost of Dystocia? Culled for Dystocia Reproductive Failure Heifers 25% Cows 58% Rogers et al., 2004

11 Reproductive Measures that Result in Pregnancy

12 Single most important measure of fertility for cow/calf producer? Annual BSE! Each bull is expected to contribute to the production Limitations: of 20 to 30 Fertility calves, measure so the fertility on that of given each day bull is at least 20x Only more about important 1/3 of the than Fertility a cow. Picture

13 Effect of Social Dominance on Percentage of Calves Sired

14 Effect of Social Dominance on Percentage of Calves Sired

15 Effect of Social Dominance on Percentage of Calves Sired What if the dominant bull is sterile?

16 Bull Dominance or Bull Fertility? Bull 4 Bull 3 Bull 2 Bull 1 Percent of calves sired by: A B C D E F G H I J K L M N O P Q Pasture

17 Bull Dominance or Bull Fertility? Percent of calves sired by: Bull 4 Bull 3 Bull 2 Bull 1 USDA-MARC, Clay Center, NE 17 Pastures Average of 42 cows/pasture (range of 31 to 66) Average of 9 bulls/pasture (range of 7 to 12) 42 d breeding season Each bull in the pasture sired at least 1 calf 10 0 A B C D E F G H I J K L M N O P Q Pasture

18 Bull Dominance or Bull Fertility? Bull 4 Bull 3 Bull 2 Bull 1 Percent of calves sired by: A B C D E F G H I J K L M N O P Q Pasture

19 Bull Dominance or Bull Fertility? Bull 4 Bull 3 Bull 2 Bull 1 Percent of calves sired by: In 47% of pastures >50% of the calves were 20 sired 10 by a single bull (Range: 31% to 67%). 0 A B C D E F G H I J K L M N O P Q Pasture

20 Bull Dominance or Bull Fertility? Bull 4 Bull 3 Bull 2 Bull 1 Percent of calves sired by: In 82% of pastures >40% of the calves were 20 In only 1 pasture did the second most fertile sired 10 by a single bull. or dominant bull sire >16% of the calves. 0 A B C D E F G H I J K L M N O P Q Pasture

21 Key Parameters of Sperm Fertility MEMBRANE INTEGRITY (1) BROKEN, OPENS THE DOOR TO DNA CAPACITATION (5) PREPARE SPERM TO FERTILIZE ACROSOME (3) KEY ROLE IN FERTILIZATION DNA CONTENT (2) CONTROL DNA FRAGMENTATION Bacterial count CONTAMINATION ALTERS FERTILITY MITOCHONDRIAL STATUS (4) INFLUENCE MOTILITY EasyCyte Flow Cytometer Measuring these key physiological functions provides insight into the fertilization potential of sperm. Evaluates 5000 sperm/min

22 Fertility of a Single Service: Beef Cattle Percentage, % ~ 25% Loss Fertilization Pregnancy d 27 Pregnancy d 42 Calving

23 Estrous Cycle Ovulation Ovulation Uterus COX, PGFS Prostaglandin (PGF 2α ) Hormone Level CL Progesterone Estrogen Day of Estrous Cycle Estrus Estrus

24 Maternal Recognition of Pregnancy Uterus COX, PGFS Prostaglandin (PGF 2α ) Hormone Level Progesterone Estrogen IFN-τ Embryo Day of Estrous Cycle Estrus Estrus

25 Maternal Recognition of Pregnancy Uterus COX, PGFS Prostaglandin (PGF 2α ) Hormone Level Progesterone Estrogen IFN-τ Embryo Estrus Day of Estrous Cycle

26 Maternal Recognition of Pregnancy Failure Uterus COX, PGFS Prostaglandin (PGF 2α ) Hormone Level Progesterone Estrogen IFN-τ Embryo Estrus Day of Estrous Cycle

27 Maternal Recognition of Pregnancy Failure Uterus COX, PGFS Prostaglandin (PGF 2α ) Hormone Level Progesterone Estrogen IFN-τ Embryo Management can cause this scenario: ANYTHING Day of Estrous Cycle Estrus that delays embryo growth can affect pregnancy establishment! Estrus

28 Why / Where is pregnancy failing? Day 1 95% Progress difficult without earlier pregnancy diagnosis Oocyte Competence Oviductal support Embryo Elongation MRP (IFN-τ) Uterine dependent period Day 27 70% d 1-4 d 5-14 d d Spencer et al. 2004

29 Post AI Management Anecdotal evidence Heifers developed in feedlots (high energy diet) to facilitate AI Conception rates vary tremendously (40-70%) Does Post-AI nutritional management play a role? Green grass????

30 Feedlot AI, then to Grass (~30 d) AI Conception rate, % BCS 5 BCS BCS 7 + Body condition score at AI Losing BCS Gaining BCS Data from George Perry (SDSU)

31 Post AI Nutrition Study All heifers gaining 1.5 lbs/d from midwinter to breeding 21 d after breeding: Control (continue 1.5 lbs/d) Drop to maintenance 80% of maintenance Post AI Weight: = Gaining = Maintaining = Losing - Scott Lake (UW) & Ron Lemanger (Purdue), 2012

32 21 d Post-AI Nutrition Pregnancy rate, % AI 2nd Service Breeding Season Gaining Maintaining Losing Heifer weight change (1 st 21 d) P < 0.05

33 Recent Reciprocal ET Study Identified Key Elements of Fertility GnRH-induced Ovulatory Follicle Size Embryo Donor Cow Large Embryo Recipient Cow Large Small Day 7 after AI Small

34 Reciprocal ET Study - Summary 3 Primary Measures of Fertility: Fertilization Success Embryo Survival to day 27 Embryo Survival to day 72

35 Recent Reciprocal ET Study Identified Key Elements of Fertility High Progesterone after breeding What decreases Progesterone? Negative energy balance Increased milk Excess protein Stress???

36 Vaccination Program Cow Herd Calves Bull Feeder Cattle Effects on fertility?

37 Timing of Vaccination Synch Breeding Immune Response Fertilization 0 6/10/06 6/24/06 7/8/06 7/22/06 8/5/06 8/19/06 9/2/06 9/16/06 9/30/06 10/14/06 10/28/06 11/11/06 11/25/06 12/9/06 12/23/06 1/6/07 1/20/07 2/3/07 2/17/07 3/3/07 3/17/07 3/31/07 Dr. Russ Daly Calving

38 Conclusions Pre-breeding vaccination starts before weaning Best time for repro vaccines = 30 days prebreeding Avoid using MLV vaccines in naïve animals < 30 d before breeding Dr. Russ Daly

39 Heifer Fertility: Genetic Markers? PREGNANT n=201 OPEN HIGH FERTILE Pregnant 4/4 (n=14) SUBFERTILE Pregnant 1/4 (n=14) INFERTILE Pregnant 0/4 (n=11) TAMU Heifers to Fort Keogh 1. Embryo donors oocyte problem 2. Embryo recipients uterine problem

40 TAMU Heifers as Embryo Donors Pregnancy Rate of Fort Keogh Recipient Cows 70.0% 60.0% 50.0% 40.0% 30.0% 20.0% 10.0% 53.6% 37.5% 61.5% 0.0% High Fertile Subfertile Infertile TAMU Embryo Donor Classification

41 TAMU Heifers as Embryo Recipients Pregnancy Rate of TAMU Heifers 80.0% 70.0% 60.0% 50.0% 40.0% 30.0% 20.0% 10.0% 0.0% 69.2% 38.5% 27.3% TAMU Heifer Classification High Fertile Subfertile Infertile Infertile heifers had compromised maternal environment.

42 TAMU Heifers Sent to WSU 1. Uterine Biopsies expression profiles 2. Genetic Markers? 7 genes identified related to fertility High Fertile Subfertile Infertile

43 Why / Where is pregnancy failing? Day 1 95% What role does the bull have in pregnancy success? Oocyte Competence Oviductal support Embryo Elongation MRP (IFN-τ) Uterine dependent period Day 27 70% d 1-4 d 5-14 d d Spencer et al. 2004

44 Biological Markers Associated with Fertility Ubiquitin PNA Cellular damage Peter Sutovsky University of Missouri Acrosome reacted sperm

45 Magnetic Nanoparticle Ubiquitin-binding antibody Head of defective sperm Ubiquitin (defective sperm only)

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48 Peter Sutovsky University of Missouri IVF Using Magnetic Sperm Depletion Sperm sorted with Ubiquitin or PNA antibody resulted in greater fertilization & cleavage rate.

49 Ubiquitin / PNA Nano-Particle Field Trial Fort Keogh 390 Cows Heifers 3 Sires 4 Treatments Control 20 x 10 6 Sperm Control 10 x 10 6 Sperm Pregnancy rate Ubiquitin Sorted 10 x 10 6 Sperm PNA Sorted 10 x 10 6 Sperm Million Sperm/straw

50 Ubiquitin / PNA Nano-Particle 100% Field Trial Fort Keogh abc P < 0.10 Pregnancy rate, % 80% 60% 40% 20% a 59% bc 49% c 42% a 59% 0% 20 M Control 10 M Control 10 M Ubiquitin 10 M PNA Sperm Treatment Male fertility may account for more than 10% of pregnancy failures. 10% of the time, fertilization achieved by less optimal sperm.

51 Early pregnancy diagnosis to identify causes of Day 1 95% Oocyte Competence pregnancy failure at Fort Keogh. Oviductal support d 19 with very good accuracy Embryo Elongation Endometrial echotexture CL blood flow Current Technology (d 27) Ultrasound MRP Blood (IFN-τ) Pregnancy specific proteins Uterine dependent period Day 30 70% d 1-4 d 5-14 d d Spencer et al. 2004

52 Fertile Mating? Questions? Tom Geary

53 Path Diagram: Embryo Donor Cow Condition score ± ± Ovulation, Cyclicity d ± E2, d Days postpartum Follicle growth rate Follicle Size, d Fertilized, d Body weight P4, d Age All cows Recovered structures

54 Path Diagram: Additional Fertility Measures Embryo Donor Cow Condition score Cyclicity Ovulation, d -9 E2, d 0 Follicle growth rate Live embryo, d7 Days postpartum Follicle Size, d 0 Embryo Stage Body weight P4, d -2 RET Age Follicle Size, d ± Embryo Quality, d7

55 Path Diagram: Embryo Recipient Cow Temp E2, d0 Follicle size ± Pregnant, d 27 Age All the preceding stuff back here RET Embryo Quality Pregnant, d 72 Recipient Age

56 Some Summary Effects: Fertilization Condition score E2, d Days postpartum Follicle Size, d Fertilized, d Body weight 0.49 Age

57 Some Summary Effects: Pregnant d 27 Condition score E2, d Days postpartum Follicle Size, d 0 Fertilized, d ± (Recipient) Pregnant, d Body weight 0.49 P4, d7 Age

58 Some Summary Effects: Pregnant d 72 Condition score E2, d Days postpartum Follicle Size, d 0 Fertilized, d ± (Recipient) Pregnant, d Body weight 0.49 P4, d7 Embryo Quality, d7 Age Pregnant, d72

59 Cow Protocols COST LABOR COST LABOR

60 Heifer Protocols COST LABOR COST LABOR

61 Synchronization Products GnRH = Gonadotropin Releasing Hormone Identical $ 2.00 Equal $ 2.00 PG = PGF = Prostaglandin F 2α 2 cc 5 cc

62 Synchronization Products MGA = Melengestrol Acetate Feed Additive Progestin = Progesterone Like Intra-vaginal Device Progesterone CIDR = Controlled Internal Drug Releaser Not Equal CIDR = Much better job of inducing estrous cycles

63 THE ESTROUS CYCLE Ovulation GnRH PGF 2α FSH E2 LH Ovulation Hormone concentration CL Progesterone Uterus PGF 2α Estrus Estrus

64 Follicular Waves during Anestrus GnRH.Before puberty.after calving Ovulate Initiate Cyclicity Ovarian Follicular Pool Die

65 In Utero Influence on Development of Replacement Heifers Uterine environment: Dam s nutrition during embryo & fetal development = lifelong effects.

66 IVOMD and CP Availability: Montana TDN, kg IVOMD and CP Grings et al., Protein, g/d January February March April May June July August September October November December Month

67 Cow Energy & Protein Requirements Energy (TDN), kg Calving Breeding IVOMD and CP Grings et al., Protein, g/d January February March April May June July August September October November December NRC, 2000 Month

68 Possible Mechanism(s)? Corpus Luteum Sensitivity to PGF 2α Adrenal Stress Temperature Epinephrine CRH ACTH Cortisol PGF 2α Gonadotrope LH Liver Cortisol P4-R Endometrial? Steroid Metabolism?