The document describes the male and female reproductive systems of dogs and rabbits. It defines key terms like fertilization, implantation, and signs of being in heat. It explains the functions of main parts like the testes, ovaries, uterus, and vagina. Hormonal changes of the menstrual cycle and how they affect the ovaries and uterus are summarized. The key differences between animal and avian reproduction are outlined. Causes and treatments of infertility in males and females are also discussed.

1. Animal Reproductive
System

2. Reproductive System of a Male
Dog

3. Functions of the main parts of the Male reproductive system
Bladder
Seminal Vesicle
Prostate gland
Cowper’s Gland
Sperm duct Penis
Urethra
Epididymis
Testis
Produces
1. Sperm Scrotum
2 Testosterone

4. Functions of the main parts of the Male reproductive system
Bladder
Seminal Vesicle
Prostate gland
Cowper’s Gland
Sperm duct Penis
Urethra
Epididymis
Testis
Stores sperm
Scrotum

5. Functions of the main parts of the Male reproductive system
Bladder
Seminal Vesicle
Prostate gland
Cowper’s Gland
Sperm duct Penis
Urethra
Epididymis
Testis
Carries sperm from the Scrotum
epididymis to the urethra

6. Functions of the main parts of the Male reproductive system
Bladder
Seminal Vesicle
Prostate gland
Cowper’s Gland
Sperm duct Penis
Urethra
Epididymis
Testis
Produces Seminal Fluid
- For sperm to swim in Scrotum
- Nourishment for sperm

7. Functions of the main parts of the Male reproductive system
Bladder
Seminal Vesicle
Prostate gland
Cowper’s Gland
Sperm duct Penis
Urethra
Epididymis
Testis
Tube through which
the sperm travel Scrotum
through the penis

8. Functions of the main parts of the Male reproductive system
Bladder
Seminal Vesicle
Prostate gland
Cowper’s Gland
Sperm duct Penis
Urethra
Epididymis
Testis
Keeps testes at a lower Scrotum
temperature

9. Functions of the main parts of the Male reproductive system
Bladder
Seminal Vesicle
Prostate gland
Cowper’s Gland
Sperm duct Penis
Urethra
Epididymis
Testis
Places sperm in the Scrotum
females body

10. Summary of functions of main parts of male reproductive system
Part Function
Testis Produces sperm and testosterone
Epididymis Matures and stores sperm
Sperm duct Carries sperm from the epididymis to the urethra
Seminal vesicles, Produces seminal fluid which feeds the sperm and
Cowper’s gland and allows them to swim. Sperm and seminal fluid are
Prostate gland collectively called semen.
Urethra Allows the passage of either urine or sperm.
Penis Places sperm inside the body of a female
Keeps testes at a lower temperature (35°). This is the
Scrotum
optimum temperature for Meiosis to occur.

11. Reproductive System of a Female
Rabbit

12. Functions
• Ovary
– These produce the eggs and female hormones
• Fallopian Tube
– Funnels at the tip of each tube catch the egg after it is released
from the ovary
– The egg is either fertilised or dies in the fallopian tube
• Uterus
– Also called the womb
– embryo implants here and develops into foetus
• Vagina
– Allows entry of sperm.
– Lined with cells that produce mucous. This serves to protect
against the entry of pathogens

13. Structure of the Female reproductive system
Fallopian tube
(Oviduct)
Funnel
Ovary
Ovarian Ligament
Uterus
Lining of uterus
(endometrium)
Cervix
Wall of uterus
Vagina
Vulva

14. Functions of the main parts of the female reproductive system
Fallopian tube
(Oviduct)
Funnel
Ovary
Ovarian Ligament
Uterus
Lining of uterus
(endometrium)
Cervix
Wall of uterus
Vagina Produces :
1. Egg
Vulva 2. Oestrogen
3. Progesterone

15. Functions of the main parts of the female reproductive system
Fallopian tube
(Oviduct)
Funnel
Ovary
Ovarian Ligament
Uterus
Lining of uterus
(endometrium)
Cervix
Wall of uterus
Vagina
1. Catches the egg after release from ovary
Vulva 2. Transports egg from ovary to womb
3. Site of fertilisation

16. Functions of the main parts of the female reproductive system
Fallopian tube
(Oviduct)
Funnel
Ovary
Ovarian Ligament
Uterus
Lining of uterus
(endometrium)
Cervix
Wall of uterus
Vagina
1. Implantation
Vulva 2. Hold foetus
3. Forms placenta

17. Functions of the main parts of the female reproductive system
Fallopian tube
(Oviduct)
Funnel
Ovary
Ovarian Ligament
Uterus
Lining of uterus
(endometrium)
Cervix
Wall of uterus
Vagina
Vulva 1. Allows entry of sperm into female system
2. Birth canal to allow exit of baby

18. Summary of functions of main parts of female reproductive system
Part Function
To produce the egg (ova). To produce the hormones
Ovary
oestrogen and progesterone
Fallopian tube Catches the egg from the ovary and transports it to
(oviduct) uterus. Site of fertilisation.
Site of implantation. Holds the developing embryo.
Has a lining (endometrium) enriched with blood
Uterus vessels to nourish the embryo.
Forms the placenta.
Vagina Allows entry of sperm and exit of baby at birth.

19. Reproductive Terms
• Castration
– Surgical removal of the testes
– Permanent closing of the sperm ducts
• Insemination
– In many species the male can be artificially stimulated to ejaculate
and the semen collected. It can then be diluted, stored and used to
inseminate females
• Fertilisation
– Fusion of the female egg and male sperm nuclei to form diploid
zygote
• Crossbreeding
– A crossbreed or crossbred usually refers to an animal with purebred
parents of two different breeds, varieties, or populations
• Hybrids
– the offspring resulting from cross-breeding of different plants or
animals

20. Fertilisation
Fertilisation is the fusion of the egg and sperm nuclei to form a
diploid zygote.

21. Fertilisation
Fertilisation usually occurs in
the fallopian tube.

22. Fertilisation
The acrosome releases enzymes to digest the egg membrane
A number of sperm may reach the egg at the same
time.
The sperm loses its tail and the head enters the egg.
The sperm and egg nuclei fuse to form a zygote
A chemical reaction at the membrane prevents other sperm
cells entering.

23. Implantation
Implantation is the embedding of the fertilised egg into the
lining of the uterus
• This occurs 6 - 9 days after fertilisation.
• By this time the zygote has
grown into an embryo.
• During implantation a membrane called the amnion
develops around the embryo. This secretes amniotic fluid
which will surround the developing embryo and act as a
shock absorber.
• After implantation the placenta forms.

24. Zygote
Implanted embryo
Implantation is the embedding of the fertilised egg into the
lining of the uterus

25. Signs of a female in season
• When on heat a bitch has a blood stained
discharge from the vulva that changes a
little later to a straw coloured one that
attracts all the dogs in the neighbourhood.
• Female cats “call” at night, roll and tread
the carpet and are generally restless but
will “stand” firm when pressure is placed
on the pelvic region (this is the lordosis
response).

26. • A female rat shows the lordosis response
when on heat. It will “mount” other females
and be more active than normal.
• A cow mounts other cows (bulling),
bellows, is restless and has a discharge
from the vulva.

27. Age and Time of Year species will
come into season
• Only a few animals breed throughout the year. This
includes the higher primates (humans, gorillas and
chimpanzees etc.), pigs, mice and rabbits. These are
known as continuous breeders.
• Most other animals restrict reproduction to one or two
seasons in the year-seasonal breeders
– It means the young can be born at the time (usually spring)
when feed is most abundant and temperatures are favourable.
– It is also sensible to restrict the breeding season because
courtship, mating, gestation and the rearing of young can
exhaust the energy resources of an animal as well as make
them more vulnerable to predators

29. Photoperiod
• The timing of the breeding cycle is often determined by
day length.
– the shortening day length in autumn will bring sheep and cows
into season so the foetus can gestate through the winter and be
born in spring.
– In cats the increasing day length after the winter solstice
(shortest day) stimulates breeding.
• The number of times an animal comes into season
during the year varies, as does the number of oestrous
cycles during each season
– a dog usually has 2-3 seasons per year, each usually consisting
of just one oestrous cycle.
– In contrast ewes usually restrict breeding to one season and can
continue to cycle as many as 20 times if they fail to become
pregnant.

30. If fertilisation has not occurred the
The Menstrual Cycle cycle begins again with the breakdown
of the endometrium.
28 1 2
27
26 3
4 DAY 1-5 : Blood from the
25
5 womb lining is shed from
24 the body
23 6
22 7 After day 5 the lining of
the uterus repairs and
21
8 builds up again
20
9
19
18 10
Fertile period
17 11
16 12
15 14 13
Implantation may happen Ovulation occurs on Day 14

31. Inside the Ovary Developing Graafian follicle –
secretes oestrogen
Potential egg
Egg is released from ovary Graafian follicle now changes to
(ovulation) the Corpus luteum which
secretes progesterone

32. Graafian follicle Corpus Luteum
Oestrogen________
Progesterone _____
s eno m o H
r
rt e m dn E
o
5 14 Days 28

33. Hormones
• The corpus luteum continues to secrete progesterone and
oestrogen during pregnancy. These maintain the lining of
the uterus and prepare the mammary glands for milk
secretion. Later in the pregnancy the placenta itself takes
over the secretion of these hormones.
• Chorionic gonadotrophin is another hormone secreted by
the placenta and placental membranes. It prevents uterine
contractions before labour and prepares the mammary
glands for lactation.
• Towards the end of pregnancy the placenta and ovaries
secrete relaxin, a hormone that eases the joint between the
two parts of the pelvis and helps dilate the cervix ready for
birth.

34. Main Differences between Animal
and Avian Reproduction
• Male birds have testes and sperm ducts and male
swans, ducks, geese and ostriches have a penis.
However, most birds make do with a small amount of
erectile tissue known as a papilla.
• To reduce weight for flight most female birds only have
one ovary - usually the left, which produces extremely
yolky eggs. The eggs are fertilised in the upper part of
the oviduct (equivalent to the fallopian tube and uterus of
mammals) and as they pass down it albumin (the white
of the egg), the membrane beneath the shell and the
shell are laid down over the yolk. Finally the egg is
covered in a layer of mucus to help the bird lay it

35. • Most birds lay their eggs in a nest and the hen
sits on them until they hatch. Ducklings and
chicks are relatively well developed when they
hatch and able to forage for their own food. Most
other nestlings need their parents to keep them
warm, clean and fed. Young birds grow rapidly
and have voracious appetites that may involve
the parents making up to 1000 trips a day to
supply their need for food.

36. Main Differences between Animal
and Avian Reproduction
• Some male birds have a penis but most
have a small amount of erectile tissue
known as a papilla
• All females have only one ovary to reduce
weight.

37. Female Reproductive Organs of a
Bird

38. Infertility
Infertility is the inability of a pair of mates to
achieve conception.

39. Male infertility disorders
• Low sperm count – Refers to a low number of
sperm per ml of seminal fluid.
• Low sperm mobility - If movement of the sperm
is slow, not in a straight line or both, the sperm
may have difficulty passing through the cervical
mucous or penetrating the shell of the egg.
• Endocrine gland failure – A failure of the testes
to produce sperm

40. Low sperm count
Causes:
• Abnormalities in sperm production or
obstruction of the tubes through which
sperm travels

41. Low sperm count
Treatment
• A change in diet
• Medication

42. Female infertility disorders
• Blockage of the Fallopian Tube
– Scarring of the fallopian tube can block the
passage of the egg to the uterus
• Endocrine gland failure
– A failure of the ovaries to produce an egg

43. Blockage of the fallopian tubes
Causes:
• Fragments of the uterus lining may spread to the
fallopian tube
• Inflammation as a result of infection
Treatment
• In-vitro fertilisation (I.V.F.)