Flashcards Animal Science ~ Reproduction

Puberty

Approaching sexual maturity

Gametes

Reproductive cells, egg or sperm

Cryptorchid

Testicles remain in body when should be suspended

Castration

Removal of Testicles

Ovulation

Egg released from follicle of ovary

Estrous Cycle

From ovulation to ovulation, days

Estrus Cycle

In heat, mating activity, hours

Gestation

Time from breeding to birth, Pregnancy

Order of Female anatomy (outside in)

Vulva, Vagina, Cervix, Uterus, Oviducts, Ovaries

Vulva

External, 2 skin flaps that are kept closed to keep unwanted things out

Vagina

Female Copulatory organ, Birth canal during parturition

Parturition

Giving Birth

Cervix (Steel door)

Tough/Cartilaginous structure that acts as a barrier, secretes mucus, unique structure among species

What does mucus do from the cervix

Lubricates the vagina, helps sperm transport, creates cervical seal of pregnancy

Cow & Ewe Cervix structure

Has rings

Sow cervix structure

Pads that create a corkscrew shape - matches boar penis

Horse cervix structure

Loose, long folds

Uterine Body

Site of pregnancy development, contractions aid sperm transport, secretes hormone

Uterine Horns

Secretes hormones to regulate estrous, level of development varies

Mare Uterine development

Large body, poorly developed horns

Cow & ewe uterine development

Moderately developed uterine horns

Sow uterine development

Very developed uterine horns -> litter bearing species

Oviducts

Tube connecting ovary to uterus

Main function of Oviduct

transport egg to the site of fertilization, then to uterus

Infundibulum

Catches egg after ovulation

Ovary Functions

Secretes hormones & Develop female gametes

What 2 hormones does the ovary secrete

Estrogen & Progesterone

What is the site of follicle development

Ovary

What is the order of follicle development

Primordial -> Primary -> Secondary -> Tertiary -> Graafian

Corpus Luteum

Yellow body, left after follicle released from ovary

What hormone does the Corpus Luteum produce

Progesterone

What hormone do developing follicles produce

Estrogen

Why are Poultry females different

No heat or estrous cycle, no gestation or pregnancy

How often do female chicks lay an egg

Approximatly every 24 hours

Albumen

Egg White

What adds the albumen in eggs

Magnum

What adds the Shell membrane

Isthmus

What adds the egg shell

Uterus

Scrotum

Sack-like structure housing testicles

Scrotum Functions

Temperature control, Protection

Spermatic Cord

Suspends the testicles into the scrotum

Parts of the spermatic cord

Vas deferens, Cremaster muscle, Paniniform plexus

Vas deferens

Transports sperm to the accesory glands

Cremaster muscle

Raises and lowers testicles when hot/cold

Pampiniform plexus

Blood network for heat transfer away from testicles

Testicles

Suspend from body by spermatic cord, housed in scrotum

Testicles Function

Make sperm cells in seminiferous tubules, Secrete testosterone from Leydig cells

Castration

Removal of testicles - cut spermatic cord + excision of testicles from scrotum

Why do we castrate

Improve meat quality (boar taint), Prevent unwanted pregnancies, Animal docility -> safety

Epididymis

Storage and maturation of sperm

Vas Deferens

Transport tube for sperm from epididymis to accessory sex glands

Accessory Sex Gland function

Addition of fluid volume, nutrients, buffers to semen

Accessory sex glands

Ampulla, Vesticular glands, Prostate, Bulbourethral gland

Urethra

Canal carrying multiple fluids (Semen, Urine)

Semen

Fluid ejactulated, Sperm + Sex gland fluids

Penis

Copulatory organ, passageway for fluids and semen to exit the male tract

Glans penis

Tip of the penis with different shapes varying on species

Sigmoid Flexure

S shape that straightens when erect, present in ruminants

Male poultry reproductive tract

Testes in body cavity, vas deferens leads to papilllae

Sperm

Male gamete

How do we evaluate Semen quality

Breeding Soundness Exam (BSE)

3 Parts of a sperm

Head, Midpiece, Tail

Sperm abnormalities

Proximal droplet, bent tail, detached tail

Endocrine system

Organs and glands that secrete hormones to regulate body functions

Reproductive Endocrine Organs

Hypothalamus, Pituitary gland, ovary, testicles, placenta

Anestrus

A period when estrous cycles stop

Polyestrus

Estrous cycles throughout the year

Seasonal Estrous

Estrous cycles only during certain seasons

Monoestrus

One estrous cycle per year

Follicular Phase

20%, Time of dominant follicle growth

Luteal Phase

80%, Development & function of the corpus luteum, progesterone secreted

Estrous synchronization

Use of synthetic hormones to control the timing of the estrous cycle

Definitive signs of heat in cattle

Will stand to be mounted

Heat behavior in swine

Female seek male, stand/lock up, increased vocalization, erect ears, swollen, red vulva, discharge

Culling

Removing animals from the herd based on health, behavior, structure, udder, productivity

Reproduction Process

Breeding, Fertilization, Gestation, Parturition

Gestation

Process of a fetus developing inside the uterus

Placenta

Connects dam to fetus (temporary)

Placenta function

Grow fetus, eliminate waste, produce progesterone, stimulate mammary glands

Freemartin

Heifer + Bull twins, heifer calf infertile - placenta shared - blood flow shared - hormones shared

What is expelled from the body during parturition

Fetus + Placenta

Dystocia

Difficulty giving birth

Postpartum interval

From birth to next estrus cycle (ovulation)

What does colostrum provide

Passive immunity, antibodies, proteins

Alveoli/Alveolus

Secretory cells producing milk

Milk movement order (ducts)

Gland Cistern, Teat Cistern, Streak Canal

Somatic Cells

Body cells - undergoes mitosis

Gamete cell division

Single chromosome, meiosis

Genes

Unit of chromosome, carry genetic code to control life processes

Genome

Complete gentic material of a species

Inheritance

Transfer of genes from parent to offspring

Alleles

Alternative form of specific gene

Homozygous

Both alleles are the same (BB) (bb)

Heterozygous

Both alleles are different (Bb)

Dominance

1 gene overpowers info of its allelic pair (Bb)

Recessive

1 gene underpowered by pair

Phenotype

What an animal looks like

Genotype

The genetic makeup of an animal

Codominance

Both alleles expressed - Shorthorn (Roan)

Incomplete Dominance

No one gene has dominance - Intermediate - Smokey animal/gray