A mare is a female horse aged 3 or older. A mare's reproductive abilities begin to decrease at age 16. Foaling occurs after an 11 month gestation period. Mares experience seasonal estrous cycles controlled by exposure to light and melatonin levels. Stallions reach puberty at 15 months but are usually not used for breeding until age 3. Sperm production takes 57-60 days. Foals are born front feet first and must drink the mare's first milk, called colostrum, within 30 minutes. Proper nutrition and vaccination protocols are important for mare and foal health during and after pregnancy.

1. Equine Reproduction

2. The Mare A Mare is a female horse 3 years or older A mare’s reproductive abilities begin to decrease at 16 yrs of age

3. Reproduction Quiz Bowl Questions: What is the difference between a mare and a filly? According to the American Quarter Horse Association breed registry, in what month would a horse born in March be considered a yearling? At what age does a mare’s reproductive ability decrease? What is a A wet mare? What is a mare classified as if she has never been bred before? Mare is 3 or over, Filly is under 3 January 16 years A mare that is nursing a foal Maiden

4. The Mare Gestation Pregnancy Lasts 11 months

5. The Mare Seasonal Polyestrous Increasing day length turns the mare “on” Decreasing day length turns the mare “off” June 21 Estrous Mar 21 Sept 21 Anestrus Dec 21

6. The Mare Anestrus Short days or absence of light causes pineal gland in brain to produce more melatonin High levels of melatonin suppress production of GnRH by the hypothalamus – keeping the mare in anestrous

7. The Mare Put her “under lights” It will take 60-90 days to induce ovulation Up to 16 hours of light/day More than 16 hrs may cause her to not cycle properly 1 - 200 watt light bulb in a 12x12 stall Should be able to read a newspaper in any corner of the stall Use of lights will also cause her to shed – have a blanket ready!

8. Reproduction Quiz Bowl Questions: During the winter months, mares are in what state of reproduction? What is a mare called that is not currently pregnant but was bred in previous or current seasons? What are 2 causes of a mare being unable to breed, or barren? Anestrous Barren Uterine infection, improper nutrition, old age

9. The Mare Estrous Also spelled oestrous Lasts 18-21 days, Average is 21 days Has 2 phases Estrus (or heat) Diestrus

10. The Mare

11. The Mare Signs of Estrus Interest in the stallion Vulval winking Squatting Tail raising Urination

12. The Mare Signs of Diestrus Kicking Biting Striking Laying the ears back Overall hostile attitude toward the stallion

13. The Mare Teasing Exposing the mare to a stallion daily while watching for the signs of estrus to determine how close she is to ovulation Scored from 0-4 A score of 0 means the mare is in diestrous A score of 3-4 means the mare is in estrous and can be bred

14. Reproduction Quiz Bowl Question: What is the average length of an estrous cycle during the breeding season in a mare? What is the range for scoring Behavioral Estrus in mares? 18-21 days 0-4

15. The Mare Estrous

16. Reproduction Quiz Bowl Questions: The corpus luteum produces what hormone? In the absence of light, the brain’s pineal gland will respond by producing what? Melatonin inhibits what hormone? What is the study of hormones and their effects called? Progesterone Melatonin GnRH Endocrinology

17. Reproduction Quiz Bowl Questions: The hypothalamus triggers what reproductive hormone? The hormone responsible for stimulating ovulation is what? Name two hormones used to manipulate a mare’s estrous cycle? GnRH Luteinizing hormone Progesterone, prostaglandins, hCG

18. Reproduction Quiz Bowl Questions: Why breed a mare as soon after January 1st as possible? How can you “induce” a mare to begin cycling? How many days does a mare need to be under artificial lighting to see a response? So that the foal will be born as close to Jan 1 as possible Put her under lights 60 days

19. The Mare

20. The Mare

21. Reproduction Quiz Bowl Questions: What organ is multi-layered, hollow, y-shaped and found in the mare’s reproductive tract? What are the highly coiled tubes that connect the tip of the uterine horn with an ovary? What acts as a physical barrier between the vagina and the uterus? Uterus Fallopian tubes Cervix

22. The Mare

23. Reproduction Quiz Bowl Questions: What is the general shape of the mare’s ovaries? Name the 6 main parts of the mare’s reproductive tract: What is at the ovarian end of the oviduct? Name the three layers of the uterus Like a kidney bean Vulva, vagina, cervix, uterus, oviduct, ovaries Infundibulum Serous, Endometrium, Myometrium

24. The Mare

25. The Mare The Ovarian Cycle

26. Reproduction Quiz Bowl Questions: How many ovaries does a mare have? What structure on the ovary forms from the tissues remaining after a follicle ruptures at ovulation? The medulla is what part of the ovary? Blood vessels and nerves which serve the entire ovary pass through what? 2 Corpus luteum The outermost area of the ovary Hilus

27. The Stallion A male horse that has not been gelded Reach puberty at approximately 15 months of age Most wait until stallion is 3 yrs to use

28. The Stallion Has increased fertility in summer Reduction in sperm production by 50% September thru February Can also be put “under lights” (just like mares) to increase sperm output in winter months Increased light causes lowered melatonin production by the pineal gland MELATONIN MELATONIN MELATONIN MELATONIN

29. The Stallion Decreased melatonin causes the Hypothalamus to produce more GnRH Production of GnRH by the Hypotahlamus causes the Pituitary gland to produce FSH and LH Hypothalamus Pituitary GnRH FSH LH FSH causes the Sertoli cells to produce sperm cells Testis Sertoli cells LH causes the Leydig cells to produce testosterone Sperm cells TESTOSTERONE Leydig cells

30. Reproduction Quiz Bowl Questions: In the stallion the hormones FSH exerts its effects on which cells? Sertoli Cells

31. The Stallion

32. The Stallion

33. The Stallion 3 phases of sperm production – in the seminiferous epithelium Spermatocytogenesis – initial division of spermatogonia Meiosis – spermatogonia are reduced in chromosome number to form spermatids Spermiogenesis – maturation of spermatids Each phase takes 18-19 dys Once they are released into tubules they are called spermatozoa

34. The Stallion Sperm cells take 57-60 days to be produced The average ejaculate contains 5-10 billion sperm cells Stressors such as fever, illness, high environmental temperatures, etc will affect quality

35. The Stallion 3 segments of the Epididymis Head (caput) Body (corpus) Tail (cauda) Spermatozoa undergo changes allowing them to swim and fertilize eggs Body Tail Storage of sperm cells Head

36. Reproduction Quiz Bowl Questions: The retention of one or both testicles in the body cavity is called what? Name the 3 parts of the epididymus: What is the master organ and site for the production of spermatozoa and testosterone? Cryptorchidism Head, body & tail The testicles

37. Reproduction Quiz Bowl Questions: Where are sperm produced? Define DSO. How many days does it take to produce sperm? Seminiferous tubules Daily Sperm Output- number of spermatozoa which can be collected per 24-hr period from a stallion and is determined by collecting the stallion for seven days. 57-60 days

38. The Stallion & The Mare 2 Types of service Natural or live cover Artificial Insemination or A.I.

39. The Foal The Foaling Process slide show

40. Reproduction Quiz Bowl Questions: During a normal foaling, will the back feet or front feet come out first? In the United States, what is the average age a foal is weaned? What is the recommended age to start de-worming a foal? What is it called when foals fail to form certain types of nerves in their intestinal tracts and die of colic within several days of birth? Front Feet 4-6 months 8 weeks Lethal White Syndrome

41. Reproduction Quiz Bowl Questions: A newborn foal must drink the mare’s first milk. What is this milk called? Most foals should be born within how many minutes? During what stage of gestation do the nutritional requirements of the mare increase? Colostrum 30 The last 3 months

42. Reproduction Quiz Bowl Questions: How many weeks before a foaling will a mare’s udder start to fill with milk? A mare should be immunized for tetanus how many days prior to foaling? The reproductive efficiency of a horse is lower, average, or higher than most domestic animals? 2-6 weeks 30 days Lower

43. Reproduction Quiz Bowl Questions: A foal normally weights approximately what percent of the mare’s body weight? Nutrition represents what percent of the total cost of managing a broodmare? What horse bi-product has been an essential component in the world’s leading human estrogen replacement therapy since 1942? 9-10% 70-80% PMU – Pregnant Mare Urine

44. Reproduction The End!