Animal Physiology and Reproduction Essential Standard 8.00 Understand animal reproduction Objective 8.01 Understand animal reproduction and parturition

Reproductive Management Terminology Castration Removing the testicles of male animals to prevent breeding Colostrum The first milk produced after a mammal gives birth that contains antibodies needed for immunity Estrus The time a female animal is receptive to be bred (also called heat) Estrus Cycle The length of a female’s cycle from one estrus to the next

Reproductive Management Terminology Gestation The time an animal is pregnant Puberty Age at which animals reach sexual maturity and begin coming into heat Lactation The period of time that milk is secreted by the mammary glands Parturition The act of giving birth by female mammals

Reproductive Management Terminology Ovulation The release of the egg cell from the ovary Fertilization The union of the sperm and the egg cells

Reproductive Traits Species Age Range of Puberty Average Length of Estrus Cycle Average Length of Estrus Average Length of Gestation Cow 6-8 months 21 days 16-18 hours 283 days Swine 4-7 months 3 days 114 days Sheep 4-8 months 22 days 30 hours 148 days Goat 1st autumn 2.5 days 151 days

Parts and Functions of the Female Livestock Reproductive System

Female Tract

Ovaries Function Produce ova called eggs Description Two oval shaped organs located near the end of the reproductive tract inside the body cavity

Female Reproductive System

Female Reproductive System The ovaries have three major functions: Gamete production Secrete estrogen (hormone) absence of muscle development development of mammary glands development of reproductive systems and external genitalia fat deposition on hips and stomach (source of energy) triggering of heat Form the corpus luteum

Oviducts Function Carry the eggs from the ovaries to the uterus Also called the fallopian tubes Description Small tubes that are near but not attached to ovaries Have small funnel-shaped end near the ovary

Female Reproductive System

Infundibulum Function Picks up eggs at ovulation and directs eggs into the oviduct Description Funnel-shaped end of each oviduct near the ovary

Uterus Function Womb Place where fetus grows and develops Description Organ with two branched horn-shaped attachments called uterine horns Will have a baby inside if animal is pregnant

Female Reproductive System

Cervix Function Description Serves as a passageway for sperm to travel from the vagina to the uterus Seats the uterus during pregnancy to prevent pathogens from affecting fetus Description Thick walled structure made up of folds and rings of muscular tissue Located at the neck of uterus Separates the uterus from the vagina

Cervix

Vagina Function Description Receives the male penis and sperm at breeding Serves as a passageway for the baby to pass through at birth Serves as a passageway for urine to be expelled Description Connects the vulva to the cervix

Vulva Function External opening to female reproductive and urinary systems Description External opening made up of folds of skin

Female Reproductive System

Reproductive Functions (Female)

Ovulation Rates Ovulation Rates by Species Cow- 1 egg per estrus Ewe- 1 to 3 eggs per estrus Sow- 10 to 20 eggs per estrus Mare- 1 egg per estrus Hen- Approx. 28 eggs per month

Reproductive Terminology Species Act Offspring Cows calving calf Ewes lambing lamb Sows farrowing pig Hens hatching chick Mares foaling foal Goats kidding kid

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Livestock and Poultry Male Reproductive Parts

Scrotum Function Holds and protects testicles Description Saclike part outside livestock that holds testicles

Testes (Testicles) Function Produce sperm and male sex hormone Description Two oval meaty structures inside scrotum in livestock and inside body cavity of poultry on each side of backbone.

Epididymis Function Stores sperm while they mature Description Long coiler tube connected to teach testicle

Vas Deferens Function Serves as a passageway for sperm to travel from the epididymis to the urethra Description Tube that connects the epididymis to urethra

Seminal Vesicles Function Produce a fluid that protects and transports sperm Description A gland that opens into urethra

Prostrate Gland Function Produces a fluid that is mixed with the seminal fluid Description Gland near the urethra and the bladder

Cowper’s Gland Function Produces a fluid that moves down the urethra ahead of the seminal fluid It cleans and neutralizes the urethra to protect the sperm Description A gland near the urethra

Penis Function Deposits semen in female animals Papila serves this function in poultry Description Rod like tissue covered by sheath

Sheath Function Protects penis from injury Description Skin that covers the penis

Reproduction in Poultry

Poultry Reproductive Systems Major difference: Embryo of livestock develop inside the female’s body while the embryo of poultry develops inside the egg. Papilla Organ in male poultry’s cloaca wall that puts the sperm in the hen’s reproductive tract. Chickens (domestic birds) only have the left ovary and oviduct functional when mature(producing eggs) The right ovary and oviduct do not function.

Other Key Points Egg-function is reproduction but it is eaten as food by humans and wild animals. Domestic chickens lay an egg every 24-48 hours regardless if sperm are not present. Commercially sold eggs are not fertilized. Incubation time for chicken eggs is 21 days. Turkeys and ducks eggs incubation is 28 days.

Parts and Functions of the Poultry Reproductive System

Ovary Poultry only have one functioning ovary as compared to livestock animals Function Produces ova and hormones The yolk of an egg is an ovum Description Attached cluster of yellow, round, egg yolks

Infundibulum Function The place where fertilization takes place Description Funnel shaped structure located just below the ovary It is the start of the oviducts

Reproduction in Poultry The poultry oviduct (tube-like structure) has five parts: 1) Vagina Holds the egg until laid 2) Uterus (shell gland) Secretes the thin, white shell and shell pigment 3) Isthmus Adds the two shell membranes 4) Magnum Secretes the albumen 5) Infundibulum Where fertilization takes place

Cloaca Function Location where the papilla of the male bird deposits semen Egg also passes through this part Description Located between the vent and base of oviduct

Vent Function Expel egg, liquid and solid waste Description Outside opening to the poultry reproductive tract

https://www.youtube.com/watch?v=G6j13-9Pexw

Parturition of Animals

Basic Facts If an ovum of the female animal is fertilized and the animal becomes pregnant, the embryo begins to grow and develop. After a period of embryological development, the developing animal is referred to as a fetus. During gestation, the fetus develops in the uterus. At the end of the gestation period, parturition begins.

Normal Presentation of the Fetus at Birth Front feet first with legs slightly offset from each other to allow for shoulders to pass through the birth canal Nose tucked between front legs Shoulders Body or middle of animal Hips Back legs and feet

Other Important Information Any presentation (at birth) that does not have the order provided is abnormal and could cause problems as severe as death of the newborn animal and/or animal.

https://www.youtube.com/watch?v=o1wqSZkPDo0

Parturition Process Begins when increased estrogen causes the uterus muscles to contract First water bag appears, enlarges, and breaks open Soon afterwards, the second water bag containing the fetus breaks open and the presentation of the calf begins Several hours later, the placenta and other members (afterbirth) are expelled If afterbirth is not expelled, the animal will become sick.

https://www.youtube.com/watch?v=XRT4to6frrU

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