1 1 To label and identify male

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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 2

Reproduction is closely related to the action of several hormones called • Produced by pituitary gland ï follicle stimulating hormone (FSH) ï luteinizing hormone (LH) • Release is controlled by gonadotropic releasing hormones or (Gn. RH) produced by the brain 3

• FSH ï stimulates follicle development ï produces estrogen in the ovary • FSH and LH combined ï prepares the follicle for ovulation • LH ï causes ovulation • Progesterone ï maintains pregnancy 4 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) causes development of secondary sex characteristics and sex behavior produce testosterone 6 • Have seminiferous tubules coil throughout testes site of sperm production and (Leydig) maturation • Have interstitial cells lie between seminiferous tubules

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

• 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 8 carries urine from the bladder carries sperm and fluid from accessory sex organs

• Provide 95 -98% of total ejaculate 9 sperm plus the added accessory fluids • Include: ï seminal vesicles (vesicular glands) ü secrete fluids providing energy and buffers to sperm ï prostate gland ü secretes a thick, milky fluid high in inorganic ions ï bulbourethral glands (Cowper’s glands) ü secrete fluids before ejaculation to clean urethra

• 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 Supplied with blood vessels 10

• 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 11

Both the male and female poultry reproductive systems vary compared to other domestic animal species 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 12

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• Produce eggs • Produce female hormones ï estrogen ï progesterone maintains uterine lining during pregnancy stimulates the development of secondary sex organs and sexual receptivity keeps estrus from occurring 14 causes mammary system to develop

• Follicle ï blister-like mass on the surface of an ovary containing a developing ovum (egg) 15 follicle ovum

• Follicle ï functions ühold the growing ovum üproduce and store estrogen ï at ovulation, the follicle ruptures, expels the ovum, enters the infundibulum and awaits fertilization in the oviduct 16 secreted from follicle to signal the remainder of the reproductive tract to prepare for ovulation

• Corpus Luteum (CL) ï forms after ovum is released from the follicle ï function üproduce progesterone 17

• Transport eggs from ovary to uterus • Are site of fertilization • Pick eggs at ovulation and direct them into the body of the oviducts 18 process of discharging an ovum from the mature follicle of an ovary

• 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 19

• Is receptacle for the penis during copulation • Serves as birth canal at parturition • Is separated from uterus by the cervix major barrier and protection of the uterus and developing fetus • Is passageway for expelling liquid wastes 20

• Is external portion of the female reproductive tract • Serves to: ï protect internal system from infection ï initially receive the penis at copulation ï act as passageway for urine • Sensory erectile organ 21

Both the male and female poultry reproductive systems vary compared to other domestic animal species 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 parts 22 1. 2. 3. 4. 5. funnel: receives yolks from ovary and stores sperm cells magnum: secretes thick white of egg isthmus: adds two shell membranes uterus: adds thin white and outer shell vent: opening where egg is laid

• 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 long phase; period from ovulation to CL regression 23

• Is categorized by frequency of occurrence throughout the year ï seasonally polyestrus— cycles occur only during certain times of the year cycle when day length increases cycle when day length decreases 24

• Is categorized by frequency of occurrence throughout the year ï monoestrus— one cycle per year; estrus periods last for several days Example: dogs ï polyestrus— uniform, regularly occurring estrous cycles throughout the year Example: cattle and swine 25

• Proestrus ï begins after CL regression and ends at the onset of estrus, period of follicle growth • Estrus ï period of sexual receptivity; sometimes referred to as “heat” • Metestrus ï early postovulatory period; CL begins to develop • Diestrus 26 ï begins approximately four days after ovulation and ends with the regression of the CL

• Before ovulation ï egg cell is contained in follicle release of egg cell from ovary; occurs near the end of estrus period • During ovulation ï follicle breaks, releases the egg into the oviduct ï if sperm is present, egg may become fertilized • After ovulation ï CL forms on ovary and releases progesterone If egg is not fertilized, CL does not grow, allowing another follicle to grow and another estrus period to occur 27

• Functions of progesterone ï prepares uterus for implantation of the embryo ï stops other eggs from forming ï maintains pregnant condition ï develops mammary glands which produce milk to feed young after they are born 28

time in which female is pregnant • 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 29

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 30

COW Estrus 10 – 26 hrs. (18 hr avg. ) Estrous Cycle 18 – 24 days (21 day avg. ) Ovulation 4 – 16 hrs. post estrus Gestation 283 days EWE SOW Estrus 20 – 42 hrs. (30 hr avg. ) Estrous Cycle 15 – 18 days (17 day avg. ) Ovulation 12– 18 hrs. estrus onset Gestation 150 days 1 – 4 days (2 day avg. ) Estrous Cycle 16 – 25 days (21 day avg. ) Ovulation 31 Gestation 16 – 48 hrs. estrus onset 114 days (3 months, 3 weeks, 3 days)

GOAT Estrus 2 – 3 days (2. 5 day avg. ) Estrous Cycle 15 – 24 days (21 day avg. ) Ovulation Near end of estrus Gestation 151 days POULTRY Estrous Cycle 15 – 18 days (17 day avg. ) Ovulation 12– 18 hrs. estrus onset 150 days 4 – 9 days (5 day avg. ) Estrous Cycle 15 – 24 days (21 day avg. ) Ovulation 32 Gestation 20 – 42 hrs. (30 hr avg. ) Gestation MARE Estrus 1 – 2 days before end of estrus 336 days

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? 33

4. Which specie discussed has the longestation length? 5. Gonadotropins are produced by which gland? 6. What male hormone is responsible for the development of secondary sex characteristics? 34

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? 35

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? 36

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 G. W. Davis 37 Production Manager Geoff Scott ©MMIII, MMIV CEV Multimedia, Ltd.