Animal Science: Chp. 10 - Reproduction

__________ _______ is a measure by the number of calves or lambs per 100 breeding females or the number of pigs per litter.

Reproductive efficiency

What is considered twice as important as economic returns of livestock production as growth or carcass performance?

reproduction

The two functions of ovaries (female) are the production of the _______(eggs) and the production of ________ (estrogen and progesterone).

oocytes; hormones

Each oocyte or egg in a female develops in a follicle. The _______ ________ grows larger and larger to eventually form a _____ _____. (or ovulating follicle.)

Primordial follicle; Graafian follicle

All of the eggs that females produce are found in their ovaries as _______ _______ before they are born. Therefore, a female is born with all the eggs she will ever produce.

primordial follicles

T/F Multiple follicles/oocytes at different stages can be found in an ovary at the same time.

true

After ovulation occurs (release of the egg/oocyte), tissue called the ____ ______ begins to form around the "wound" or hole at which the oocyte was released.

corpus luteum

What's the one function of the corpus luteum?

to produce progesterone (hormone of pregnancy)

After an oocyte is released from an ovary/follice, it travels into the ________. The ________ is the "baseball mitt" part which catches the released oocyte from the follicle ensuring that it doesn't fall into the body cavity.

oviduct; infundibulum

The two functions of the oviduct are it _______ the oocyte and sperm and functions as the site of ________ and early development.

transports; fertilization

List the four functions of the uterus

1. assits in sperm transport

2. regulation of the corpus luteum

3. site of attachment and pregnancy

4. expulsion of the fetus and fetal membranes

Livestock species uteri differ by the length of the _____ ______ and size of the ______ ______

uterine horns (2); uterine body

The cervix facilitates ________ ________ and prevent _____ ________. (physical barrier and secretion of mucus)

sperm transport; uterine contamination

T/F The cervix is a barrier to the external environment which helps prevent an infection in the uterus which would be bad because that is where the fetus is housed.

true

The vagina acts/functions are the ________ _________(used to engage in sexual intercourse) and the ______ _________.

copulatory organ and birth canal

List the 5 female reproductive organs

ovaries, oviducts, uterus, vagina, cervix

List the two functions of the testicles (2 testes)

produce sperm cells and testosterone

The testes are suspended from the body by the spermatic cord. This helps with _______ ________ because sperm do not like to be hot! - Need to be 4-6 degrees cooler than the body

temperature regulation

The testes are housed in the ________, a two-lobed sac that __________ and also helps _______ ________.

scrotum; protects; regulate temperature

The epididymis is a coiled tube inside the testes that function as the....

maturation and storage site for sperm

The vas deferens (aka ductus deferens) is the duct that functions in _____ _________: carries sperm from epididymis up into body and into the urethra when the animal is sexual excited.

sperm transport

T/F The urethra in a male transports urine, but the reproductive tubes or vas deferen joins it in the penis.

true

What are the main functions of the accessory sex glands?

add volume and nutrition to sperm-rich fluid (coming from epididymis)

Sperm + accessory gland fluid =

semen

These are the four ________ _________ ________: ampullae, seminal vesicles, prostrate, bulbourethral glands.

accessory sex glands

The penis functions as a copulatory organ which ____ ______ to the female tract.

delivers sperm

The two types of penises are:

- _________: spongy, erectile tissue that fills with blood during arousal, causing erection

- ________: sigmoid flexure (s-shaped) that extends straightens causing erection

vascular; fibroelastic

Which mammals have a vascular penis? (spongy, erectile tissue that fills with blood during arousal, causing erection)

stallion, dogs, cats, humans

Which mammals have a fibroeslatic penis? (sigmoid flexure (s-shaped) that extends straightens causing erection)

bull, boar, and ram

The _____ _______ is the tip of the penis, where most nerve endings are located.

glans penis

Which hormone initiates ovulation in the female causing corpus luteum formation and progesterone production?

luteinizing hormone (LH)

Which hormone initiates the development of the follicle in a female causing estrogen synthesis and (in the male) sperm production and testosterone synthesis?

follicle-stimulating hormone (FSH)

Which hormone is involved in gamete transport, uterine contraction (during birth in a female), and milk let down?

oxytocin

Which hormone is found mostly in females and initiates secondary sex characteristics, uterine growth (female), and mating behavior?

estrogen

Which hormones helps maintain pregnancy and initiates mammary development?

progesterone

Which hormone is found mostly in males and initiates anabolic growth (overall body/muscle growth), sperm production, and secondary sex characteristics?

testosterone

Which hormone is involved in partial control of seasonal reproductive patterns?

melatonin

Which hormone is released from the uterus and intimates the regression of the corpus luteum, uterine contraction, and ovulation? This hormone is produced when pregnancy doesn't not occur.

prostaglandin F2a

What is the hormone that drives everything in reproduction? It is released from the hypothalamus and initiates the release/inhibit of all the hormones needed for reproduction?

gonadotropin-releasing hormone

T/F In males, hormones are fairly simple, straightforward, and consistent whereas in females hormones are never simple, straightforward, or consistent.

true

The ______ _______ is the predictable pattern of events that allow for multiple opportunities for pregnancy.

estrous cycle

An animal that has more than one estrous or heat cycle per year is ________. (cattle, swine)

polyestrous

An animal that has repeated estrous cycles or heat cycles only during specific times or seasons throughout the year are ______ __________. (goats, sheep, horses)

seasonally polyestrous

An animal that has one or two cycles per year is _________. (dog)

monoestrus

The ______ _______ in males tells the Leydig cells in the testicles to produce testosterone.

anterior pituitary

The ________ in males send factors through the blood vessels that affect the anterior pituitary's production of FSH (follicle stimulating hormone) and LH (luteinizing hormone).

hypothalamus

The _______ ______ of the estrous cycle includes proestrus and estrus stages.

follicular phase

________ describes the time during the follicular phase of the estrous cycle where the follicles form to produce estrogen. This is what brings females into heat and behavior to receive a male.

Proestrus

_______ describes the time during the follicular phase of the estrous cycle when ovulation occurs.

Estrus

The _____ ________ of the estrous cycle includes the metestrus and diestrus phases.

luteal phase

__________ describes the time during the luteal phase of the estrous cycle where CL is formed and progesterone is secreted.

Metestrus

___________ describes the time during the luteal phase of the estrous cycle where there is a sustained release of progesterone.

Diestrus

If pregnancy doesn't occur, the uterus will release _________ which causes the regression of CL and progesterone.

PGF 2a

The average length of the estrous cycle in heifers/cows (cattle), gilts/sows (swine), does (goats), and heifers/cows (bison) is...

21 days

The average length of the estrous cycle for ewe's (sheep) is...

17 days

The average length of the estrous cycle for mare's (horse) is...

22 days

When sperm and oocyte UNITE = _________ = ________

fertilization; conception

The fertilized oocyte begins to divide as it moves down the ______ and into the ________. When it arrives and the fetal membranes form it is _________.

oviduct; uterus; conceptus

Because the progesterone from corpus luteum is essential, that structure must be _________ rather than regressing to start the cycle over.

maintained

T/F The process of "maternal recognition of pregnancy" keeps the corpus luteum functional.

true

The ________ is an organ that creates the metabolic connection between embryo/fetus and dam. It also produces hormones that maintain pregnancy, prepare mammary system, and enhance growth of fetus.

placenta

A ___________ placenta has an even distribution of chorionic vili and can be found in which 2 types of animals?

diffuse; sow and mare

A ____________ placenta has placentomes and can be found in which 3 types of animals?

cotyledonary; cows, ewes, does

A ________ placenta has a distinct zone where all exchange occurs and occurs in which 2 types of animals?

zonary; cats and dogs

A __________ placenta has disc-like structure where all exchange occurs and occurs in which 2 types of animals?

discoid; primates and rats

The functional unit of the fetal placenta is the _____ _______.

chorionic villous

Gestation length for a cow

285 days

Gestation length for a ewe

147 days

Gestation length for a mare

336

Gestation length for a sow

114 days

Gestation length for a doe

150 days

Parturition (labor/birth which includes the delivery of fetus and placenta) is initiated by the release of _________ (stress hormone) from the fetus.

cortisol

T/F Uterine contractions are necessary (takes a change in hormones) and in most species (except pigs) there is a "proper" birthday position.

true

T/F Ability of every female to give birth to live offspring is a key to successful reproduction

true

______ is the hormone of pregnancy and the _______ is the organ of pregnancy.

Progesterone; uterus