1

2

1. To label and identify male and female reproductive anatomy

2. To describe the structures and functions of male and female reproductive anatomy

3. To understand the animal reproductive process, including the estrous cycle, ovulation, gestation and parturition

3

Reproduction is closely related to the action of several hormones called

• Produced by pituitary gland

follicle stimulating hormone (FSH)

luteinizing hormone (LH)

• Release is controlled by gonadotropic releasing hormones or (GnRH) produced by the brain

4

• FSH

stimulates follicle development

produces estrogen in the ovary

• FSH and LH combined

prepares the follicle for ovulation

• LH

causes ovulation

• Progesterone

maintains pregnancy

changes in the hormones secreted by the ovary and pituitary gland during estrous cycle

5

6

• Are paired, oval shaped organs

• Produce sperm cells

• Produce testosterone (male sex hormone)

• Have seminiferous tubules coil throughout testes

• Have interstitial cells (Leydig) lie between seminiferous tubules

causes development of secondary sex

characteristics and sex behavior

causes development of secondary sex

characteristics and sex behavior

site of sperm production and

maturation

site of sperm production and

maturationproduce

testosteroneproduce

testosterone

7

• Protects and supports the testes

• Protects sperm

• Regulates temperature

• Lie within the wall of the scrotum

• Raise or lower the testes to maintain constant testicular temperature

Temperature should be 4 – 6° below body temperature for normal sperm development

Temperature should be 4 – 6° below body temperature for normal sperm development

8

carries urine from the bladder

carries sperm and fluid from

accessory sex organs

carries urine from the bladder

carries sperm and fluid from

accessory sex organs

• Is a coiled tube, attached to each testis

• Is responsible for further maturation, storage and transportation of sperm cells

• Transports sperm from the epididymis to the urethra Because location of testes vary among livestock

species, location of the epididymis varies

9

sperm plus the added accessory

fluids

sperm plus the added accessory

fluids• Provide 95-98% of total ejaculate

• Include: seminal vesicles (vesicular glands)

secrete fluids providing energy and buffers to sperm

prostate glandsecretes a thick, milky fluid high in inorganic

ions bulbourethral glands (Cowper’s glands)

secrete fluids before ejaculation to clean urethra

10

• Is a passageway for semen and urine

• Deposits semen in the female reproductive tract

Primarily composed of connective tissue and depends little on blood for

erections

Primarily composed of connective tissue and depends little on blood for

erections

Supplied with blood vessels

Supplied with blood vessels

11

• Has a s-shaped curve

• Allows for penis retraction

• Stallions and humans do not have sigmoid flexure

• Extends the penis upon sexual excitement

• Protects penis from injury and infection

12

How Male Anatomy Differs

• Testes are located within the abdominal cavity, produce sperm and seminal fluid

• Papillae emit semen and are considered the copulatory organs of the rooster

• Cloaca serves as passageway for urinary, digestive and reproductive tracts

• Androgen is the male sex hormone produced by the testes

Both the male and female poultry reproductive systems vary compared to other domestic animal species

13

14

stimulates the development of secondary sex organs

and sexual receptivity

stimulates the development of secondary sex organs

and sexual receptivity

• Produce eggs

• Produce female hormones

estrogen

progesterone

maintains uterine lining during pregnancy

keeps estrus from occurring

causes mammary system to develop

maintains uterine lining during pregnancy

keeps estrus from occurring

causes mammary system to develop

15

• Follicle

blister-like mass on the surface of an ovary containing a developing ovum (egg)

follicle

ovum

16

• Follicle

functions

hold the growing ovum

produce and store estrogen

at ovulation, the follicle ruptures, expels the ovum, enters the infundibulum and awaits fertilization in the oviduct

secreted from follicle to signal the

remainder of the reproductive tract to prepare for ovulation

secreted from follicle to signal the

remainder of the reproductive tract to prepare for ovulation

17

• Corpus Luteum (CL)

forms after ovum is released from the follicle

function

produce progesterone

18

• Transport eggs from ovary to uterus

• Are site of fertilization

• Pick eggs at ovulation and direct them into the body of the oviducts

process of discharging an ovum

from the mature follicle of an ovary

process of discharging an ovum

from the mature follicle of an ovary

19

• Consists of horns and a body

− uterine horns

− uterine body

• Is site of embryonic growth

• Is site of placental and fetal development

• Varies in shape among species

A sow has a very long uterus and a mare has a very short uterus

20

• Is receptacle for the penis during copulation

• Serves as birth canal at parturition

• Is separated from uterus by the cervix

• Is passageway for expelling liquid wastes

major barrier and protection of the uterus and developing fetus

major barrier and protection of the uterus and developing fetus

21

• Is external portion of the female reproductive tract

• Serves to:

protect internal system from infection

initially receive the penis at copulation

act as passageway for urine

• Sensory erectile organ

22

How Female Anatomy Differs

• Mature female poultry have only one functional ovary and oviduct (left ovary)

• Ova produced in ovary are developed into egg yolks

• Oviduct has five parts1. funnel: receives yolks from ovary and stores sperm cells

2. magnum: secretes thick white of egg

3. isthmus: adds two shell membranes

4. uterus: adds thin white and outer shell

5. vent: opening where egg is laid

Both the male and female poultry reproductive systems vary compared to other domestic animal species

23

• Reoccurs and repeats itself as long as the female is not pregnant

• Is controlled by hormones preparing the reproductive tract for ovulation and pregnancy

• Includes two phases

1. follicular phase

2. luteal phase

short phase; period from

regression of the CL to ovulation

short phase; period from

regression of the CL to ovulation

long phase; period from ovulation to CL regressionlong phase; period from

ovulation to CL regression

24

• Is categorized by frequency of occurrence throughout the year

seasonally polyestrus— cycles occur only during certain times of the year

cycle when day length increases

cycle when day length decreases

25

• Is categorized by frequency of occurrence throughout the year

monoestrus— one cycle per year; estrus periods last for several days

Example: dogs

polyestrus— uniform, regularly occurring estrous cycles throughout the year

Example: cattle and swine

26

• Proestrus begins after CL regression and ends at the onset of

estrus, period of follicle growth

• Estrus period of sexual receptivity; sometimes referred to as

“heat”

• Metestrus early postovulatory period; CL begins to develop

• Diestrus begins approximately four days after ovulation and

ends with the regression of the CL

27

• Before ovulation

egg cell is contained in follicle

• During ovulation

follicle breaks, releases the egg into the oviduct

if sperm is present, egg may become fertilized

• After ovulation

CL forms on ovary and releases progesterone

release of egg cell from ovary;

occurs near the end of estrus period

release of egg cell from ovary;

occurs near the end of estrus period

If egg is not fertilized, CL does not grow, allowing another follicle to grow and another estrus period to occur

28

• Functions of progesterone

prepares uterus for implantation of the embryo

stops other eggs from forming

maintains pregnant condition

develops mammary glands which produce milk to feed young after they are born

29

• Fetus develops in uterus and is surrounded by a watery membrane

• Blood vessels in umbilical cord supply nutrients, oxygen and carry off waste products

• Placenta is connected to the fetus by the umbilical cord and lies along wall of uterus

• Food, oxygen and wastes are exchanged between mother and fetus through the placenta

time in which female is pregnant

time in which female is pregnant

30

process of giving birth

process of giving birth

• Near the end of the gestation period, the CL decreases its production of progesterone

• Increased estrogen levels, cause uterine muscles to contract, beginning the birthing process

• Sequential set of events:

1. cervix widens (dilates)

2. pelvic region relaxes

3. uterus begins contractions

4. fetus passes through the cervix, pelvic region and finally the vagina

31

Estrus 10 – 26 hrs. (18 hr avg.)

Estrous Cycle 18 – 24 days (21 day avg.)

Ovulation 4 – 16 hrs. post estrus

Gestation 283 days

SOWSOWEstrus 1 – 4 days (2 day avg.)

Estrous Cycle 16 – 25 days (21 day avg.)

Ovulation 16 – 48 hrs. estrus onset

Gestation 114 days (3 months, 3 weeks, 3 days)

EWEEWE

Estrus 20 – 42 hrs. (30 hr avg.)

Estrous Cycle 15 – 18 days (17 day avg.)

Ovulation 12– 18 hrs. estrus onset

Gestation 150 days

COWCOW

32

Estrus 2 – 3 days (2.5 day avg.)

Estrous Cycle 15 – 24 days (21 day avg.)

Ovulation Near end of estrus

Gestation 151 days

MAREMAREEstrus 4 – 9 days (5 day avg.)

Estrous Cycle 15 – 24 days (21 day avg.)

Ovulation 1 – 2 days before end of estrus

Gestation 336 days

POULTRYPOULTRY

Estrus 20 – 42 hrs. (30 hr avg.)

Estrous Cycle 15 – 18 days (17 day avg.)

Ovulation 12– 18 hrs. estrus onset

Gestation 150 days

GOATGOAT

33

1. Which part of the male reproductive anatomy is responsible for further maturation, storage and transportation of sperm cells?

2. What female hormone prepares the uterus to maintain implantation of the embryo?

3. What term is used for the process of giving birth?

34

4. Which specie discussed has the longest gestation length?

5. Gonadotropins are produced by which gland?

6. What male hormone is responsible for the development of secondary sex characteristics?

35

7. Name two functions of the scrotum?

8. Accessory glands provide what percent of the total ejaculate?

9. Which part of the female reproductive tract is the site of fertilization?

36

10.Which part of the female anatomy serves as the birth canal at parturition?

11.Name the two phases of the estrous cycle?

12.Animals cycling when day length increases are considered to be what type of breeders?

37

Pond, Kevin R., and Wilson G. Pond. Introduction to Animal Science. John Wiley & Sons, Inc., 2000.

Reece, William O., Physiology of Domestic Animals. College of Veterinary Medicine, Iowa State University. Williams & Wilkins, 1997.

Sam Prien, Ph.D. Texas Tech University Health Sciences Center

Production Coordinator Clayton Franklin

Executive Producer Production Manager G.W. Davis Geoff Scott©MMIII, MMIV

CEV Multimedia, Ltd.