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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
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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
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• 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
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• 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
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• 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
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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
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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
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• 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
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• 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
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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
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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
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• Follicle
blister-like mass on the surface of an ovary containing a developing ovum (egg)
follicle
ovum
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• 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
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• Corpus Luteum (CL)
forms after ovum is released from the follicle
function
produce progesterone
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• 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
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• 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
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• 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
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• 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
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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
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• 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
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• 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
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• 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
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• 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
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• 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
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• 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
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• 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
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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
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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
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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
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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?
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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?
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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?
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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?
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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.