1. Equine Reproduction

2. Definitions Gestation: time of pregnancy.
Range days
Parturition: Birthing process
Fertilization: when the egg meets the sperm and the zygote is formed.
Implantation: When the egg attaches to the wall of the uterine horn to get food

3. The Mare’s Reproductive System
Mares have complicated reproductive processes, and they do not easily become pregnant.
Each mare has her own reproductive pattern, and knowing that pattern is the key to increasing the chances of fertilization.

4. Female Anatomy
Ovary: the main organ of reproduction.
kidney-shaped organs that produce hormones and the ova (eggs).
The ovaries are small and hard while inactive.
Oviduct: a tube from the ovaries to the uterine horn.
When the egg reaches the oviduct it can be fertilized by sperm cells if they are present

5. Fimbria:(infundibulum)funnel shaped end of the oviduct near the ovary; catches the egg and funnels it into the oviduct.

6. Female (dam) Anatomy
Uterine Horns: area between the oviduct and the uterus.
Where implantation of the egg occurs
Uterus : area between the horns and the cervix
lined with the placenta that the growing fetus fills
Cervix: Tightly knotted muscle that regulates what enters or leaves the uterus
Dialates during parturition

7. Female Anatomy Vagina: area between the cervix and the vulva
Birth canal
Vulva: opening to the outside world
Clitoris: sensory organ

8. Female ReproductiveTract

10. Equine Reproduction Male (sire) Anatomy
1. Testes:
Site of sperm production; produce the male hormone testosterone.
2. Scrotum:
Protective sack around the testes; helps to regulate the temperature of the testes. The cremaster muscle contracts to draw the testes up toward the body during cold weather to keep them
warm, and relaxes to lower them away
from the body to keep them cool when
the weather is hot.

11. Stallion
3. Epididymis:
The site of sperm storage and maturation.

12. Stallion parts 4. Vas deferens:
The passageway for the sperm to pass from the epididymis to the urethra and accessory sex glands in the pelvic region.
5. Penis:
The copulatory organ
of the stallion.

13. Stallion Parts 6. Prepuce: 7. Accessory sex glands:
Loose surrounding skin that protects the free end of the penis.
7. Accessory sex glands:
Contribute fluids that serve as a buffer and source of nutrients for the sperm cells: bulbourethral gland, prostate gland, vesicular gland.

14. Stallion

15. Stallion

16. Libido stands for: Sex drive of a stallion
Spermatozoa mature in the epididymis

17. (GnRH) gonadotropin releasing hormone
GnRH stimulates the secretion of the gonadotropins, follicle stimulating hormone (FSH) and luteinizing hormone (LH)

18. FSH and LH stimulate the ovaries

19. Gestation period Length - Horses
Range days
Average 336 days

20. Progesterone
Hormone produced at the uterus to maintain the pregnancy.

21. Gestation period length
Knowledge of the length of gestation period is important to the producer because:
a. it helps to regulate production cycles
b. it helps in the planning of the breeding program
c. it helps to predict the date of birth

22. Abortion -
EXPULSION of the fetus before the time of PARTURITION.

23. Causes for abortions: 1. Infections
a. Bacteria and Fungi (ex., Rhinopneumonitis, Vibriosis)
b. Viral (ex., influenza)
c. Protozoans (ex., Trichomoniasis)

24. Causes for abortions: 2. Genetic Abortions
a. Occur when the fetus is malformed
b. Dam's body usually rejects the malformed fetus for reasons unknown.

25. Causes for abortions: 3. Injury related abortions
a. Rare because fetus is well protected
b. Prevent injuries caused by kicking, bumping, or squeezing

26. Causes for abortions: 4. Nutrition Examples: - Poisonous Plants
- Ration too low in required nutrients

27. Development 3 periods of development from pregnancy to birth
- Ovum Period
- Embryonic Period
- Fetal Period

28. Ovum Period ( Days 0 to 25 in horses)
1. Fertilization
2. Cell Division

29. Stages during the ovum period
Zygote – 2 to 8 cells

30. Stages during the ovum period
Zygote – 2 to 8 cells
Morula – spherical mass of cells (outer layer and central core)

31. Stages during the ovum period
Zygote – 2 to 8 cells
Morula – spherical mass of cells (outer layer and central core)
Blastula -- mass of cells with a hollow cavity

32. Embryo Period (Days 25 to 60 in horses)
3. Implantation - the new embryo becomes implanted in the uterine horn where it will be nourished and develop.

33. Abnormal implantation
Ovarian: Young seldom survive to full term
Tubal: Young rarely survive to birth
Abdominal: Young do not survive to full term

34. Embryo Period
4. Differentiation - cells become organized into specific structures

35. Embryo Period
5. Completion of all major ORGAN systems.

36. Embryo Period
6. Looks like the ORGANISM.

37. Fetal Period (Days 60 to 336 in horses)
7. Placentation - MEMBRANES develop to provide the FETUS with NUTRITION.
Each embryo usually has their own set of membranes

38. Placental Structures:
Amnion – inner most layer that forms a sac around the embryo/fetus. (Amniotic Sac)
Filled with amniotic fluid that protects young from shock and adhesion

39. Types of placental attachment
Diffuse – contact is made over most of the uterus
Mares, sows, humans

40. Placental Structures
Umbilical Cord - long FLEXIBLE tube attached to the placenta where FOOD, OXYGEN, and WASTES are exchanged between the MOTHER and the baby.

41. Placental Barrier
Placenta prevents large molecules from passing from mother to young.
Viruses are small enough to penetrate as are certain other chemicals.

43. Fetal Period
8. Growth and Development - the fetus GROWS and organs continue to DEVELOP so that the animal can LIVE on its OWN.

45. Parturition -the act of giving birth

46. Signs of birth in horses
weeks prior, udder swells
days prior, muscles shrink and abdomen drops
days prior, teats fill with milk
hours prior, “wax” appears on nipples (“waxing”)

47. Stages of Parturition (Labor)
Stage 1 - Preparatory Stage
Stage 2 - Expulsion of fetus
Stage 3 - Expulsion of the placenta
Stage 4 -Period of Rest

48. Preparatory Stage
1. Restlessness of animal due to minor contractions
2. Dilation of the cervix
3. Cervix expands allowing uterus and vagina to
become a continuous
canal

49. Expulsion of the fetus
1. Increased contraction (abdominal pressing marks)
2. Straining followed by a few minutes of rest
3. Fetus enclosed in amnion, propelled through birth
canal and appears at vulva

52. Expulsion of the fetus
5. In horses, placental connections are broken. 2nd stage must be rapid

53. Expulsion of placenta (afterbirth)
1. Caused by uterine contractions
2. Placenta should be expelled within 12 hours following parturition

54. Expulsion of placenta (afterbirth)
(foaling problems, abortion, twins, etc., may cause it to be retained)
3. Used to remove retained placenta by hand, now we treat it with antibiotics.

55. Stage 4
Period of Rest

56. Proper Presentation
Most common is forelegs first with nose resting on the forelegs (anterior)
Mild labor pains usually start several hours before actual birth

57. Proper Presentation

58. Head and Hind legs Forward

59. Neck Presented

60. Proper Presentation
First water bag will appear on the outside increasing in size until it ruptures due to its own weight
Immediately after the first bag, the amniotic bladder (second water bag) follows, containing the fetus

61. Proper Presentation
Presentation of fetus after straining on the mares part
If presentation is normal and within 45 minutes to an hour hours after the first signs of foaling, then no assistance is necessary

62. Always treat the umbilical cord with iodine after birth

63. Dystocia
Difficulty during parturition

64. Fetal Dystocia problems
Over sized fetus
Multiple births
Breech presentation
Deviations in normal presentation

65. Maternal dystocia problems
Narrowing of the birth canal due to fractures of the pelvis
Twisted uterus reducing size of birth canal
Cervix fails to dilate
Absence of uterine contractions
Caused by large litter size or exhaustion due to fetal dystocia

66. Stall preparation for birth
should be bedded with straw.
Wood shavings and other similar bedding materials should be avoided because they may stick to the foal's wet nostrils and suffocate it.

67. Should I lend assistance?
What is the due date?
How long has the animal been trying to give birth?
Has the animal given birth before?

68. Should I lend assistance?
Have some offspring already been delivered?
Has anyone attempted to assist yet?
Should I assist or call vet?

69. Behavior after giving birth
Postpartum Behavior
Behavior after giving birth

70. Postpartum Behavior in Mares
Following birth the mare often lies exhausted for minutes
Mares do not eat the afterbirth, but will groom their foals

71. Foals must nurse soon after birth to get the colostrum that has the antibodies for the immune system

72. Estrous Cycle

74. SEASONAL POLYESTRUS
During winter season, mares are in reproductive quiescence (or hibernation) called anestrus.
will not respond to the stallion's attention
During this season of reproductive activity, the mare will experience a series of estrous cycles.

75. Mares Estrous cycle
cycles will repeat at 21- to 23-days

76. Estrus (heat) lasts an average of five to seven days.
Estrus is characterized by receptivity to the stallion.