2. General Information 1
• Reproduction is a complicated process in all
species of animals
http://piximg.corbis.com/cpe/256wm/101http://asnet.tamu.edu/www/ansc108/PICS/Boar.jpg53713.jpg
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
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)
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)
– Cow 35-42 cm
– Ewe 12-17 cm
– Sow 16-23 cm
– Mare 30-47 cm
• Semen deposit
– Cows and ewes have semen deposited here, mares and
sows have semen deposited in cervix.
25. Cervix
• “Mouth of womb”
– 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
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
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
http://asnet.tamu.edu/www/ansc108/PICS/Boar.jpg
32. Why Castrate
• Makes male animals less aggressive and
easier to handle
•http://www.viewimages.com/viewimage/?imageid=102497&promotionid=1&partnerid=2&type=results
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”
