1. Anatomy and Physiology: Reproductive Systems (3025B)By
Jessi Spry and Kathryn Shaull

2. General Information 1
Reproduction is a complicated process in all species of animals

3. General Information 2
The anatomy of both the male and female must be compatible.

4. General Information 3
Physiological compatibility and timing is also required
Must have similar genetic makeup
The female must be willing in heat to accept the male
Ovum must be mature and ready to be fertilized
Dependent on the proper function of many organs

5. General Information 4
Any abnormality in the anatomy or physiology of the reproductive tract result in lower fertility or complete sterility of the animal

6. Anatomy of the Male Reproductive Tracts
Less complex than the females.
Goal is to produce large numbers of viable male sex cells called spermatozoa.
Contributes ½ of the chromosomes to each of his offspring

7. Male Reproductive Tracts
After mating the role of the male is over
Reproductive organs in the various mammalian species are similar in form and function

8. Male Reproductive Tract-Picture

10. Scrotum
Testes or testicles in the male are the primary sex organs and are held in a sac called the scrotum
Produce spermatozoa and testosterone
Normally two testicles in a scrotum

11. Scrotum Functions as a heat regulating mechanism.
4 or 5 degrees below body temp. is essential for spermatogenesis – growth and maturation of the sperm

12. Testicles
Some animals only have one or neither testicle drop out of the body cavity into the scrotum
A monorchid as one fertile testicle
Although the testicle in the body does not produce viable spermatozoa, it does produce testosterone
Cryptorchid is sterile and means neither dropped.

13. Urethra
Begins at the opening of the bladder and is continuous with the penis.
In mature bulls, the posterior portion of the urethra is S-shaped – known as the sigmoid flexure

14. Urethra
Extends the penis outside of the body and into the vaginal cavity of the female so that the semen can be deposited.

15. Urethra
If the Sigmoid flexure does not work you have the equivalent of the sterile male
The retractor muscle retracts the penis into the protective sheath

16. Urethra “Accessory Sex Glands” along the urethra include the:
Prostate Gland
Two seminal vesicles
Two Cowper’s

17. Urethra
The accessory Sex Glands provide a medium for the transport of the sperm from the testes to the vagina.
The Medium includes:
Adds Volume
Provides Nutrients for the sperm
Cleans and flushes out the urinary tract.
Makes a plug to hold the semen in the vagina (in some species)

18. Any Questions?

19. Important Roles of Females
Provides 1/2 of the chromosomes of the young
Nourishes young in her uterus and after birth until weaning

20. Female Reproductive Tract
Female Tract consists of:
Vulva
Vagina
Cervix
Uterus
Uterine horn
Fallopian tubes
Ovaries

22. Vulva
Exterior portion of the reproductive tract

23. Vagina Region between the vulva and the cervix
Semen is deposited in this region in cows and ewes

24. Vagina Compared Length (Vagina + Vestibule) Semen deposit Cow 35-42 cm
Ewe cm
Sow cm
Mare cm
Semen deposit
Cows and ewes have semen deposited here, mares and sows have semen deposited in cervix.

25. Cervix “Mouth of womb” Semen deposited here in mares and sows
The opening into the uterus through which sperm must pass to fertilize the egg.
Semen deposited here in mares and sows
Area stretches during birth to allow passage of newborn
Becomes blocked by mucus plug to protect it from harmful infections

26. Cervix

27. Uterine Horns The two branches of the uterus
Fallopian tubes or ovuducts are located at the end of each horn
lined with microscopic cilia
help guide egg (ovum) to the horn
Usually the site of sperm and ovum uniting

28. Uterine Horns

29. Any Questions?

30. Value of Castration
Definition: removal of the testicles by either surgical or non-surgical methods

31. Ages for Castration Recommended Calves: 1-3 months Lambs: 7-14 days
Pigs: 1-3 weeks

32. Why Castrate Makes male animals less aggressive and easier to handle

33. Aggression Due to the effects of “androgens”
androgens: hormones that control the appearance and development of masculine sex characteristics
Removal of testes stops production
Primary androgen is “testosterone”

35. Selected Resources