Animal Science 3

Puberty

Approaching sexual maturity

Gametes

reproductive cells

egg/sperm

Cryptorchid

one or more testicles remain in the body cavity when they should be suspended

Castration

removal of the testicles

Ovulation

Eggs release from the follicle of the ovary

Estrous Cycle

from one ovulation to the next

17-21 days

Estrus

in heat and looking for a mate

lasts hours, not days

Gestation

the time from breeding to birth

pregnancy

Gestation length for cows

285 days

gestation length for Ewes

147 days

Swine gestation length

147 days

Gestation length of Horses

336 days

Vulva

The external part of the female reproductive tract

Labia

the two skin/muscle flaps that keep the vulva closed

Vagina

the female copulatory organ

birth canal during birthing process

Parturition

the process of giving birth

Cervix

tough, carligious structure that acts as a barrier in the female reproductive tract

what aids with sperm transport, and is lubricated by mucus in the female reproductive tract

Cervix

What are the two main parts of the Uterus

Uterine body

Uterine horns

Uterus

site of pregnancy development

site of contractions during pregnancy

Which part of the Uterus is responsible for hormone secretion

uterine horns

Oviducts

a tube connecting the uterine horns to the ovaries

transports the egg for fertilization

Infundibulum

catches the egg after ovulation

located between the oviducts and ovaries

ovaries

used for egg storage and hormone production

What are the female reproductive hormones

Estrogen

progesterone

What is the shape of the cervix in cows and ewes

has rings

makes AI difficult

What is the shape of the cervix in sows

padded that creates a corkscrew shape

What is the shape of the cervix in Mare’s

loose, with long folds

Uterus makeup of Mare’s

poorly developed horns

large uterine body

Uterus makeup of Cows and Ewes

moderately developed Uterine horns

Uterus makeup of Sows

very developed uterine horns

What makes certain livestock able to have large litters

large, developed uterine horns

What is developed in the ovaries

egg follicles

What are the smallest of the follicles

primordial

What types of follicles drop and become eggs

Graafian (preovulatory)

Where is Estrogen produced

in the Ovum

What are the Corpus Luteum (the yellow body)

the leftovers of ovulation

leaves a large scar tissue

what process produces progesterone

ovulation

Corpus Albican (white body)

The healing of the leteum

the ovary regenerates itself

What process produces Estrogen

follicle development

Hens have how many ovaries and oviducts

2 and 2

How long does it take for a Hen to ovulate and lay an egg

about 24 hours

What is the yolk of a hen egg similar too

Follicles

How long is the yolk in the infundibulum

about 15min

Where is the infundibulum located

In the oviduct

What happens in the Magnum of hens

the egg white is added to the yolk

the albumen

What is the purpose of the Isthmus in Hens

The shell membrane, water, and salt are added to the egg

Where is the shell added to the egg in Hens

in the Uterus

How long does it take to add the shell to a Hens egg

about 21 hours

What is the exit path for completed eggs

Vagina

Where are the testicles housed

in the scrotum

Where are sperm cells created

seminiferous tubules

What is the purpose of the Leydig Cells

secretion of testosterone

What is the purpose of the Epididymis

stores sperm and grows them for maturity

What is the purpose of the Scrotum

used for temperature control and basic protection of the testicles

What is the purpose of the spermatic cord

suspends the testicles within the scrotum

What is the purpose of the Vas Deferens

transports the sperm to the accessory gland

the sperms “van”

Cremaster Muscle

Raises and lowers the testicles when hot or cold

Pampiniform Plexus

a blood network that transfers heat away from the testicles

Boar taint

a strong odor in the meat caused from a boar having their testicles

What is the purpose of the accessory glands in the male reproductive tract

adds fluid, nutrients, and buffers to the semen

Urethra

canal that carries Urine and Semen

Glans Penis

the tip of the penis

Sigmoid flexure

present in ruminants

a curve in the penis that straightens when erect

What is special about the testicles of poultry

the testicles are inside the body cavity

How long can a Hen store sperm inside of her

up to 2 weeks

How can we evaluate semen quality

breeding soundness exam

What are the 3 sections of sperm that we observe during a breeding soundness exam

Head

Midpiece

Tail

What is the endocrine system

organs and glands that produce hormones

these regulate body temperature

How are hormones delivered to target tissues

directly through the bloodstream

Where is the Hypothalamus located

in the brain

What is the purpose of the Hypothalamus

hormone production

releases GnRH: Gonadotropin Releasing Hormone

Where is the Pituitary gland located

in the brain

What hormone is secreted from the pituitary gland

LH: Luteinizing hormone

FSH: follicule stimulation Hormone

What is the purpose of the Luteinizing hormone

causes the follicle to break away from the ovary

Estrogen

produced by the follicle on the ovary

reasonable for mating behavior

what is the Oxytocin hormone responsible

responsible for milk letdown in the mammary gland

uterine contractions during birth

What is the hormone Progesterone used for

maintains pregnancy

tells the animal she is pregnant

What produces progesterone

the corpus luteum on the ovary

What initiates sperm production

testosterone

Anestrus

a period when estrous cycles stop

Estrus

standing heat,

a period of sexual receptivity

Estrous

the reproduction cycle

from one ovulation to the next

Polyestrous

continuous estrous cycles throughout the year

Swine

Seasonal Polyestrous

estrous cycles only during curtain seasons

sheep, horses, goats, deer

Monstrous

One estrous cycle, only during certain seasons

dogs, wolves, foxes, bears

Follicular phase

time of dominant follicle growth

ovulation

only about 20% of the estrous cycle

Luteal Phase

Development and function of the corpus luteum

progesterone is released

about 80% of the estrous cycle

What Animal(s) have a 21 day estrous cycle

Cow

Sow

Goat

What animal(s) have a 17 day estrous cycle

Ewe (sheep)

What animal(s) have a 22 days estrous cycle

Mare

How do we manipulate the estrous cycle of cattle

inject hormones

How do we manipulate the estrous cycle of pigs

synchronize the weaning so they come into heat within 3-4 days

How do we manipulate a horses estrous cycle

regulate their lighting schedule

more light = more cycles

Poultry

Manipulate the amount of light they receive

Seedstock/ purebred breaders

use the same breed of livestock

Commercial producer breeding

Generally crossbreed to combine the best triats

What is Culling

taking animals out of the breeding heard

Embryo

sperm+oocyte

undergoes cell division to become a fetus

What is parturition

the birthing process