Animal Breeding & Genetics
Animal Reproduction: Reproductive Anatomy
REPRODUCTION
in order for a species to thrive, it must be able to
reproduce itself
producing offspring requires the proper functioning of both
the male and female reproductive systems, each of which
consists of several pars that have specific purposes in the
reproductive system 4. EPIDYDYMIS
hormones also play an important role in reproduction ➔ a tube w/ 3 parts: head, body, tail
sperm in stored in the epididymis
MALE REPRODUCTIVE SYSTEM
for maturation
the male animal possesses special reproductive organs also concentrates the sperm &
these organs are similar in all male mammals, although transports it from the testicles to
some differences in form & function exist the vas deferens
made up of Head (caput
epididymis), Efferent ductules,
Seminiferous tubules, Tail (cauda
epididymis, Body (corpus
epidydymis), Ductus deferens
5. VAS DEFERENS
➔ a tube that transports sperm from the
MALE REPRODUCTIVE SYSTEM : Parts & Functions epididymis to the urethra
6. URETHRA
1. SCROTUM
➔ carries sperm & urine to the penis & outside the
➔ a sac or pouch of skin that carries the
body
testicles and regulates their temperature
when cold, the testicles are
drawn close to the body for
warmth
in hot weather, the testicles hang
away from the body
* sperm temp. must be lower
than the body; sperm dies
when temp. is too hot
2. CREMASTER MUSCLE
➔ lowers or raises the penis to control its
temperature
3. TESTES
➔ produce sperm cells and testosterone
7. ACCESORY GLANDS
COWPER’s (bulbourethral) GLAND
→ paired; secretes fluids that cleanse &
neutralize urethra to allow the sperm to
survive the passage to the penis
- the secretions pass through the urethra prior to the
semen when mating
, into left & right halves by a septum; w/
sparse hair (densely covered w/ hair in
VESICULAR GLAND small ruminants); w/ a distinct neck
→ paired; secretes fructose (energy source above the testis
of the sperm), in the form of a pouch or Cat subanal; testes are angled toward anus
vesicle inguinal region; testes are oriented w/
PROSTATE GLAND their long axis horizontally; scrotum is
→ unpaired; secretes fluid; has 2 parts – Horse thin skin, mostly pigmented, shiny & oily
disseminate & body; releases the fluid that bcs of the secretions of the sebaceous &
mixes w/ the seminal fluid & nourishes the sweat glands; w/ few fine hairs
sperm perianal; testes are angled toward anus;
AMPULLARY GLAND scrotum is wrinkled in adult boars, w/
Pig
→ paired; found at the ampulla or proximal few hairs, divided by a deep groove into
dilatation of the urethra left & right halves
* these glands provide 95-98% of
total ejaculate volume
* the combination of the sperm w/ PATH TRAVELED BY SPERM
the fluid from the seminal vesicles &
seminiferous tubules in testes – where sperm is
prostate gland is known as semen
made
8. URINARY BLADDER
then, the epididymis where sperm cells mature
➔ stores urine before it is released to the
mature sperm move into the vas deferens
urethra; has no reproductive function
then, the seminal vesicles w/c provide the sperm w/
9. SPERMATIC CORD
fluid
➔ the structure extending from the testicle
the sperm then passes through the prostate gland &
through the inguinal canal; consisting of the
cowper’s gland to receive more fluid
ductus deferens, testicular vessels & nerves
& the lymphatics & their serous coverings the sperm enters the urethra w/c runs through the
10. SIGMOID FLEXURE penis then out of the body
➔ S-curved muscle extend the penis outside
the body during mating
11. RETRACTOR MUSCLE
➔ pulls the penis back into the body
12. PENIS
➔ an organ that deposits semen into the female
reproductive tract
➔ also excretes urine from the body
13. SHEATH
➔ a fold of skin that covers & protects the penis
when it is relaxed
14. SEMINAL VESICLES
➔ produces the seminal fluid that transports &
protect s the sperm
* the reproductive parts found in the boar, stallion,
dog, & buck have functions similar to those of the bull
* the filiform appendage called urethral process found
in the ram is actually the opening of the urethra, w/c REPRODUCTIVE SYSTEM OF SPECIFIC MALE SPECIES
extends beyond the head of the penis
FOWL
* it rotates & sprays semen during mating ▪ CLOACA – the reproductive & digestive
SCROTUM OF DIFFERENT ANIMALS systems
o the cloaca of the male joins the
Animal Scrotum cloaca of the female during mating
usually pigmented (black), covered w/ (“cloacal kiss”) most birds have no penis
few hairs; located at the Inguinal region; ▪ PAPILLAE – a structure that looks like a
Dog
testes are oriented w/ their long axis bump attached to the inside wall of the
horizontally cloaca, the papillae transport the sperm to
below inguinal region; testes are the female reproductive tract during mating
Ruminants oriented w/ their long axis vertically; ▪ VENT – connected to cloaca; releases
scrotum is long & pendulous; divided digestive & reproductive products external opening
, BULL MALE BOVINE
▪ TESTICLES – paired; located in the scrotum
beneath the animal slightly hangs from the body that’s
why elastrator (elastic band) is used at the site where it hangs to
castrate bulls can only be done in ruminants
▪ EPIDYDYMIS – located in the scrotum next
to each testicle; connected to the urethra by
the vas deferens
▪ SIGMOID FLEXURE – post-scrotal
STALLION MALE HORSE
▪ SCROTUM – located further towards the
rear of the animal & is less pendulous
▪ PREPUCE – has an extra fold inside the first
since its penis is long
▪ preputial fold is the 2nd fold
prepuce inside the preputial sheath
▪ NO SIGMOID FLEXURE bcs it has diff. type of penis;
vascular penis unlike others which are fibroelastic
BOAR MALE SWINE
▪ TESTICLES & SCROTUM – located at the
rear of the boar rather than at the bottom of
the animal
o this positioning makes boar different
from bull
▪ PENIS – corkscrew shaped
▪ SIGMOID FLEXURE – pre-scrotal
▪ PREPUTIAL DIVERTICULUM – blind pocket
in the dorsal wall of the boar’s prepuce
o trapped materials here like bacteria &
smegma gives the boar its
characteristic odor
RAM MALE SHEEP
▪ FILIFORM APPENDAGE – extends from the
head of the penis
▪ SHEATH – also referred to as a prepuce
▪ SIGMOID FLEXURE – post-scrotal
, BUCK MALE RABBIT MALE REPRODUCTIVE ACCESSORY GLANDS
▪ SCROTUM – called an inguinal pouch COMPARATIVE ANATOMY
▪ PROSTATE GLAND – separated into 3
parts Animal Ampullary Vesicular Prostate Cowper’s
▪ NO COWPER’s GLAND Dog + - + -
▪ NO SIGMOID FLEXURE Tom - - + +
Boar - + + +
Stallion + + + +
Bull + + + +
Ram + + + +
Buck(goat) + + + +
2 TYPES OF PENIS
1. FIBROELASTIC PENIS
➔ characteristic of ruminant & boar
➔ large connective tissue content causes them to
be firm even when not erect
➔ erection is characterized greatly by the
straightening of the sigmoid flexure & stiffening
from engorgement of blood, w/o an increase in
diameter
2. MUSCULOCAVERNOUS (VASCULAR) PENIS
➔ characteristic of carnivores & horse & humans
➔ the low connective tissue causes them to be
FOWLS CHICKENS, TURKEY, & OTHER BIRDS
flaccid when not erect
▪ TESTICLES – located within the abdomen,
➔ erection is accompanied by engorgement of
next to the backbone
erectile tissue w/ blood, increasing the length &
▪ VAS DEFERENS – connects the testicles to
the diameter, while stiffening it blood entirely makes penis
the cloaca, papillae & vent
functional during mating
▪ PAPILLAE – small, finger-like projections
w/in the cloaca
PENIS CLASSIFICATION
▪ NO SCROTUM
▪ NO URETHRA Animal Description
▪ NO URINARY BLADDER they cant store urine; urine Dog Vascular w/ os penis (aka baculum - bones in penis)
is directly excreted Tom Vascular w/ os penis & spines
➢ most birds do not have penises. Bull Fibroelastic
Ratites (ostrich, emu, rhea) & Ram Fibroelastic, has long urethral process
Anatidae (geese, swans & ducks) Stallion Vascular
have penises w/c are being erected
Boar Fibroelastic w/ cork-screw end
by lymph & not blood opposed to
Avian Phallus is the copulatory organ w/c is not
mammals, & are an expansion of
protrusible (except in some species like
the cloacal wall;
drakes & ganders)
^ intromission = when penis enters the vagina;
^ castration/caponization: middle of the rib
* hairlike in ram = urethral process → prone to urinary calculi = amputate
Animal Reproduction: Reproductive Anatomy
REPRODUCTION
in order for a species to thrive, it must be able to
reproduce itself
producing offspring requires the proper functioning of both
the male and female reproductive systems, each of which
consists of several pars that have specific purposes in the
reproductive system 4. EPIDYDYMIS
hormones also play an important role in reproduction ➔ a tube w/ 3 parts: head, body, tail
sperm in stored in the epididymis
MALE REPRODUCTIVE SYSTEM
for maturation
the male animal possesses special reproductive organs also concentrates the sperm &
these organs are similar in all male mammals, although transports it from the testicles to
some differences in form & function exist the vas deferens
made up of Head (caput
epididymis), Efferent ductules,
Seminiferous tubules, Tail (cauda
epididymis, Body (corpus
epidydymis), Ductus deferens
5. VAS DEFERENS
➔ a tube that transports sperm from the
MALE REPRODUCTIVE SYSTEM : Parts & Functions epididymis to the urethra
6. URETHRA
1. SCROTUM
➔ carries sperm & urine to the penis & outside the
➔ a sac or pouch of skin that carries the
body
testicles and regulates their temperature
when cold, the testicles are
drawn close to the body for
warmth
in hot weather, the testicles hang
away from the body
* sperm temp. must be lower
than the body; sperm dies
when temp. is too hot
2. CREMASTER MUSCLE
➔ lowers or raises the penis to control its
temperature
3. TESTES
➔ produce sperm cells and testosterone
7. ACCESORY GLANDS
COWPER’s (bulbourethral) GLAND
→ paired; secretes fluids that cleanse &
neutralize urethra to allow the sperm to
survive the passage to the penis
- the secretions pass through the urethra prior to the
semen when mating
, into left & right halves by a septum; w/
sparse hair (densely covered w/ hair in
VESICULAR GLAND small ruminants); w/ a distinct neck
→ paired; secretes fructose (energy source above the testis
of the sperm), in the form of a pouch or Cat subanal; testes are angled toward anus
vesicle inguinal region; testes are oriented w/
PROSTATE GLAND their long axis horizontally; scrotum is
→ unpaired; secretes fluid; has 2 parts – Horse thin skin, mostly pigmented, shiny & oily
disseminate & body; releases the fluid that bcs of the secretions of the sebaceous &
mixes w/ the seminal fluid & nourishes the sweat glands; w/ few fine hairs
sperm perianal; testes are angled toward anus;
AMPULLARY GLAND scrotum is wrinkled in adult boars, w/
Pig
→ paired; found at the ampulla or proximal few hairs, divided by a deep groove into
dilatation of the urethra left & right halves
* these glands provide 95-98% of
total ejaculate volume
* the combination of the sperm w/ PATH TRAVELED BY SPERM
the fluid from the seminal vesicles &
seminiferous tubules in testes – where sperm is
prostate gland is known as semen
made
8. URINARY BLADDER
then, the epididymis where sperm cells mature
➔ stores urine before it is released to the
mature sperm move into the vas deferens
urethra; has no reproductive function
then, the seminal vesicles w/c provide the sperm w/
9. SPERMATIC CORD
fluid
➔ the structure extending from the testicle
the sperm then passes through the prostate gland &
through the inguinal canal; consisting of the
cowper’s gland to receive more fluid
ductus deferens, testicular vessels & nerves
& the lymphatics & their serous coverings the sperm enters the urethra w/c runs through the
10. SIGMOID FLEXURE penis then out of the body
➔ S-curved muscle extend the penis outside
the body during mating
11. RETRACTOR MUSCLE
➔ pulls the penis back into the body
12. PENIS
➔ an organ that deposits semen into the female
reproductive tract
➔ also excretes urine from the body
13. SHEATH
➔ a fold of skin that covers & protects the penis
when it is relaxed
14. SEMINAL VESICLES
➔ produces the seminal fluid that transports &
protect s the sperm
* the reproductive parts found in the boar, stallion,
dog, & buck have functions similar to those of the bull
* the filiform appendage called urethral process found
in the ram is actually the opening of the urethra, w/c REPRODUCTIVE SYSTEM OF SPECIFIC MALE SPECIES
extends beyond the head of the penis
FOWL
* it rotates & sprays semen during mating ▪ CLOACA – the reproductive & digestive
SCROTUM OF DIFFERENT ANIMALS systems
o the cloaca of the male joins the
Animal Scrotum cloaca of the female during mating
usually pigmented (black), covered w/ (“cloacal kiss”) most birds have no penis
few hairs; located at the Inguinal region; ▪ PAPILLAE – a structure that looks like a
Dog
testes are oriented w/ their long axis bump attached to the inside wall of the
horizontally cloaca, the papillae transport the sperm to
below inguinal region; testes are the female reproductive tract during mating
Ruminants oriented w/ their long axis vertically; ▪ VENT – connected to cloaca; releases
scrotum is long & pendulous; divided digestive & reproductive products external opening
, BULL MALE BOVINE
▪ TESTICLES – paired; located in the scrotum
beneath the animal slightly hangs from the body that’s
why elastrator (elastic band) is used at the site where it hangs to
castrate bulls can only be done in ruminants
▪ EPIDYDYMIS – located in the scrotum next
to each testicle; connected to the urethra by
the vas deferens
▪ SIGMOID FLEXURE – post-scrotal
STALLION MALE HORSE
▪ SCROTUM – located further towards the
rear of the animal & is less pendulous
▪ PREPUCE – has an extra fold inside the first
since its penis is long
▪ preputial fold is the 2nd fold
prepuce inside the preputial sheath
▪ NO SIGMOID FLEXURE bcs it has diff. type of penis;
vascular penis unlike others which are fibroelastic
BOAR MALE SWINE
▪ TESTICLES & SCROTUM – located at the
rear of the boar rather than at the bottom of
the animal
o this positioning makes boar different
from bull
▪ PENIS – corkscrew shaped
▪ SIGMOID FLEXURE – pre-scrotal
▪ PREPUTIAL DIVERTICULUM – blind pocket
in the dorsal wall of the boar’s prepuce
o trapped materials here like bacteria &
smegma gives the boar its
characteristic odor
RAM MALE SHEEP
▪ FILIFORM APPENDAGE – extends from the
head of the penis
▪ SHEATH – also referred to as a prepuce
▪ SIGMOID FLEXURE – post-scrotal
, BUCK MALE RABBIT MALE REPRODUCTIVE ACCESSORY GLANDS
▪ SCROTUM – called an inguinal pouch COMPARATIVE ANATOMY
▪ PROSTATE GLAND – separated into 3
parts Animal Ampullary Vesicular Prostate Cowper’s
▪ NO COWPER’s GLAND Dog + - + -
▪ NO SIGMOID FLEXURE Tom - - + +
Boar - + + +
Stallion + + + +
Bull + + + +
Ram + + + +
Buck(goat) + + + +
2 TYPES OF PENIS
1. FIBROELASTIC PENIS
➔ characteristic of ruminant & boar
➔ large connective tissue content causes them to
be firm even when not erect
➔ erection is characterized greatly by the
straightening of the sigmoid flexure & stiffening
from engorgement of blood, w/o an increase in
diameter
2. MUSCULOCAVERNOUS (VASCULAR) PENIS
➔ characteristic of carnivores & horse & humans
➔ the low connective tissue causes them to be
FOWLS CHICKENS, TURKEY, & OTHER BIRDS
flaccid when not erect
▪ TESTICLES – located within the abdomen,
➔ erection is accompanied by engorgement of
next to the backbone
erectile tissue w/ blood, increasing the length &
▪ VAS DEFERENS – connects the testicles to
the diameter, while stiffening it blood entirely makes penis
the cloaca, papillae & vent
functional during mating
▪ PAPILLAE – small, finger-like projections
w/in the cloaca
PENIS CLASSIFICATION
▪ NO SCROTUM
▪ NO URETHRA Animal Description
▪ NO URINARY BLADDER they cant store urine; urine Dog Vascular w/ os penis (aka baculum - bones in penis)
is directly excreted Tom Vascular w/ os penis & spines
➢ most birds do not have penises. Bull Fibroelastic
Ratites (ostrich, emu, rhea) & Ram Fibroelastic, has long urethral process
Anatidae (geese, swans & ducks) Stallion Vascular
have penises w/c are being erected
Boar Fibroelastic w/ cork-screw end
by lymph & not blood opposed to
Avian Phallus is the copulatory organ w/c is not
mammals, & are an expansion of
protrusible (except in some species like
the cloacal wall;
drakes & ganders)
^ intromission = when penis enters the vagina;
^ castration/caponization: middle of the rib
* hairlike in ram = urethral process → prone to urinary calculi = amputate
