1. EQUINE REPRODUCTION

2. TERMINOLOGY s BOOK s BOOKING FEES s STUD FEE s FOAL GUARANTEE sLive Foal sColor s WET/DRY CARE s BREEDER sThoroughbred sOther breeds s DEATH CLAUSE s CHUTE FEE

3. Stallion Physiology Onset of sexual maturity10-24 mo Life span of sperm in female tract 2-4 days Survival time with fertilizing capacity 1-2 days Sperm output Semen volume/ejaculate20-100 ml # sperm/ejaculate X 10 9 6

4. Sperm Production Sperm Output and Production is influenced by: –Season –Testicular size –Age –Frequency of ejaculation –Behavior

5. Mare Anatomy Vulva Vagina Cervix Uterus Oviducts Ovaries Left Ovary Oviduct Left Uterine Horn Uterine Body CervixVagina

6. TERMS Anestrus Diestrus Estrous Cycle Estrus MARE CLASSIFICATION Pregnant Open Barren Wet Dry MARES

7. The Open Mare Evaluate reproductive history Establish the time of year to breed Mare Plan: –Diagnose possible problems –Implement problem management –Establish estrus calendar

8. Mares Cycle

9. Photoperiod Effect Reproductive activity in spring stimulated by an increasing photoperiod Mechanism –Altered hormone secretion by pineal gland –http://www.vivo.colostate. edu/hbooks/pathphys/end ocrine/otherendo/pineal.h tml

10. Spring Transition Period Increased photoperiod stimulates the hypothalamus and pituitary Pituitary hormones (especially FSH) induce follicular development

11. Transition 1-3 waves of follicles develop & regress Estrogen produced by developing follicles Irregular/prolonged estrus exhibited 1 follicle eventually ovulates Thereafter, mares ovulate at ~21-day intervals

12. 21-day estrous cycle Estrus 5-7 d Diestrus 14-16 d

13. Estrous Cycle SunMonTueWedThuFriSat 1 2345678 9101112131415 16171819202122 23242526272829 3031

14. Go to CSU site and discuss GONADOTROPINS What does LH and FSH stand for? http://www.vivo.colostate.edu/ hbooks/pathphys/endocrine/h ypopit/lhfsh.html

15. Estrus Follicular Development & Ovulation Anterior Pituitary – FSH - follicular growth Pituitary – LH – maturation of follicle & ovulation Follicles reach 20-25 mm in diameter, secrete estrogen.

16. Prediction of Ovulation Number of days in heat Growth rate of largest follicle –Average 3-5 mm/day Size of largest follicle Softness of preovulatory follicle Ultrasound image

17. Diestrus Corpus Luteum Formation Corpus luteum - secretion of progesterone. Progesterone - responsible for keeping the mare out of heat and for maintaining pregnancy. Prostaglandin Release Prostaglandin (PGF) - released from the uterus of a non- pregnant mare 14-16 days after ovulation

18. Postpartum Estrus Foal Heat Fertile as compared to other species. Breeding may be necessary to maintain the 12 mo. Foaling interval. May be necessary to back up foaling.

19. Signs of Estrus Most consistent –Elevated tail raise –Winking –http://www.youtube.com/watch?v=Henp9 Uv21Cwhttp://www.youtube.com/watch?v=Henp9 Uv21Cw Other signs –Squatting –Urinating whitish –Video of mare interaction http://www.youtube.com/watch?v=PuGu Z9JyEz4 http://www.youtube.com/watch?v=PuGu Z9JyEz4

20. Estrus Manipulation Methods u Artificial lighting u Shortening Late Transition u Inducing Ovulation u Estrus synchronization u Estrus Synchronization & Ovulation Induction

21. Light Stimulus 14.5 hrs daylight per day (also long days done for hair coat control) 30-60 days

22. Progesterone or related compounds l Regumate – most common l Normalization of estrus l Estrus synchronization l Long-term suppression of estrus l Pregnancy maintenance

23. Lutalyse or Estrumate u Shorten interval between estrous periods u Break down the CL corpus luteum u Estrous synchronization with prostaglandins http://www.veterinarypartn er.com/Content.plx?P=A& C=301&A=2720&S=0 http://www.veterinarypartn er.com/Content.plx?P=A& C=301&A=2720&S=0

24. Breeding Methods Pasture Breeding Hand Breeding Artificial Insemination –Fresh semen –Cooled, shipped semen –Frozen semen

25. Cooled Shipped Semen ADVANTAGES Cost Genetics Disease DISADVANTAGES Cost Technology/mgmnt Stallion variability Common Problems Inability to obtain semen Poor quality semen Reordering semen Failure to predict ovulation

26. Frozen Semen Success of Frozen Semen –Fertility of stallion’s semen –Fertility of the mare –Skill of the veterinarian/technician Maximum Success –Client communication –Choose ideal candidate –History of stallion

27. Embryo Transfer Synchronization of donor and recipient mare Embryo flushing Embryo transfer procedure

29. Pregnancy Evaluation Ultrasound, 14-18 days –ID twins –ID placental development Re-evaluate, 40 days Monitor Placental function & fetal growth

30. Gestation Length Normal: 335-342 days

31. Late Pregnancy Abdomen greatly enlarged Ventral edema Mammary gland enlargement – 2-4 wk Gluteal muscles relax – 7-10 d Teats fill with milk – 4-7 d Waxing of teat ends – 1-4 d Vulva soft & relaxed – 1-2 d

32. Stages of Parturition Stage 1 –Onset: initial uterine contractions –End: rupture of chorioallantois (water bag) Stage 2 –Onset: rupture of chorioallantois –End: delivery of fetus

33. Stages of Parturition Stage 3 (< 3 hrs) –Onset: delivery of fetus –End: passage of the fetal membranes –Foaling video 7min http://www.youtube. com/watch?v=3RS Av_JIQMo http://www.youtube. com/watch?v=3RS Av_JIQMo

34. Foals and Immunity Colostrum (first milk) - antibodies 1-2 pts of high quality colostrum If adequate passive transfer occurs there will be over 400-800 mg/dl IgG Immunoglobulin antibodies in foal’s blood Takes ~ 12 hours for all antibodies ingested in colostrum to show up in the blood