Mammals and Avians' Reproductive System

reproductive system

The primary function of this is to enable reproduction, ensuring the survival of the species through the production of offspring

• Produce gametes (eggs and sperm)

• Facilitate the meeting of gametes to produce a zygote (fertilized egg)

• Enable animals to create offspring

• Provide the mechanism for the recombination of genetic material that allows for change and adaptation

• Manipulate the system in breeding management programs to allow the rapid and dramatic alteration of the conformation and productivity of domestic animals

Other functions of the reproductive system

Fertility

the capacity to reproduce successfully (both male and female).

Infertility

refers to temporary loss of fertility, whereas sterility is permanent loss of fertility.

Hypothalamus

portion of the brain found in the floor of the ventricle that regulates reproduction, hunger, body temperature and other functions.

Anterior pituitary(AP) or adenohypophysis

part of the pituitary gland located at the base of the brain that produces several hormones ( including gonadotropins)

Corpus luteum

yellowish body in the mammalian ovary developed from follicular cells which secretes progesterone

Interstitial cells (Leydig cells)

cells between the seminiferous tubules of the testicle that produce testosterone

Gonad

one of the two testes of a male or ovaries of female; organ which produce sex cells

Gonadotropin-releasing hormone (GnRH)

hormone secreted by the hypothalamus that acts on the AP to release gonadotropins(LH and FSH).

Follicle –stimulating hormone (FSH)

gonadotrophic hormone produced and released by the AP That stimulates the production of estrogens, development of ovarian follicles (together with in female and spermatogenesis in male)

Testosterone

male sex hormone that stimulates the accessory sex glands, male sex drive, and development of male secondary sex characteristics

Estrogen

hormone (including estradiol, estriol and estrone) produced mainly in the ovary and placenta responsible for female to come physiologically into heat and to be receptive to the male; cyclic change of female tubular genital tract; secondary female sex characteristics.

Progesterone

hormone produced by the corpus luteum and also at the placenta mainly responsible for progestational proliferation in the uterus for implantation and pregnancy maintenance, mammary and uterine gland development.

Sexual maturity

time/age reached when the gametes become capable of fertilization. State of full reproductive capacity

Estrous cycle

rhythmic sexual behavior patterns develop in female animals during puberty.

Estrous cycle

Also known as the “heat cycle” or the time from one heat to the next.

Polyestrous

refers to animals which have several estrous cycles per year of breeding season

Ovulation

the rupture of ripe/matured follicle as a response to L:H surge, shedding or releasing the ovum.

Superovulation

the production and release of more ova (multiple ovulation) at a single estrus, as performed in embryo transfer

Copulation or coitus

the act of sexual intercourse where semen of the male is deposited in the reproductive tract of female during mating or breeding service

Libido

male sex drive.

Semen

a mixture of sperm and accessory gland fluids.

Flehmen

behavior of male animals associated with courtship and sexual activity. Ex. Dogs, Bulls and rams smelling the urine of female in heat, stallion curling its lip upwards.

Insemination

the deposition of semen in the female reproductive tract, it can be natural or artificial

Offspring (progeny)

animals born to a parent, descendants, either the first or a later generation

Neonate

refers to newborn animal or a youn

Fetus

refers to newborn animal or a young

Fetus

refers to prenatal stage after fetal membranes (placenta) become functional or beyond the embryo stage

sib or siblings

animals with same parents like a brother/sister

Castration

Removing the testicles of the male to prevent breeding

Colostrum

first milk

Gestation

time an animal is pregnant

Estrus

When a female is receptive to be bred

Lactation

Period of time that milk is secreted by the mammary glands

Parturition

act of giving birth

Ovary

site of gamete production

• 20000

• 400000

A bovine animal has _ potential eggs per ovary, while a human female has _ potential eggs per ovary.

Ova

are fully developed at puberty and are not continuously produced as in the male

• two

• hen

• left

All species contain _ functional ovaries except for the _ which has only a _ functioning ovary.

• Gamete production

• Secrete estrogen

• Form the corpus luteum

Three major functions of Ovaries

secrete estrogen (hormone)

Major function of ovary wherein there is absence of muscle development

secrete estrogen (hormone)

Major function of ovary wherein there is a development of mammary gland

Secrete estrogen (hormone)

Main function of ovary wherein there is development of reproductive systems and external genitalia

Secrete estrogen (hormone)

Main function of ovary wherein there is fat deposition on hips and stomach (source of energy)

Secrete estrogen (hormone)

main function of ovary wherein there is triggering of heat

Uterine horn

The anterior, divided end of the uterus in the cow, ewe, and mare.

• 2

• no

Sow has only _ alarms, no body, woman has _ horns, only body.

Uterus

Muscular sac connecting fallopian tubes and cervix

Uterus

Sustains the sperm and aids in its transport

Uterus

Supports embryo and fetus during gestation

Uterus

Expels fetus at parturition

Cervix

Area between the uterus and vagina

Cervix

Normally closed

Cervix

Opens at estrus and parturition

(2 -3 inches)

How long is the cervix?

Vagina

the female organ of copulation

Vagina

admits penis

Vagina

receives semen

Vagina

passageway for fetus at parturition

Bladder

storage organ for urine

Vulva

extended genitalia; opening for both urinary and genital tracts

1. Ovulation

2. Estrus

3. Gestation

4. Parturition

5. Lactation

Steps in the female reproductive process:

Ovulation

Produce gamete (ova or ovum)

Ovulation

Release of egg(s)

Ovulation

Infundibulum pushes the ovum into the fallopian tube

Estrus

Period of time when a female will accept a male in copulation

Estrus

The female must stand (standing heat) to be mounted before the reproductive process can begin

Gestation

Fertilization to parturition

Gestation

Develop embryo in uterus

Parturition

Expel fully developed young at birth

Lactation

Milk production

1 egg per estrus

Ovulation Rates of Cow

1 to 3 eggs per estrus

Ovulation rate of Ewe

10 to 20 eggs per estrus

Ovulation rate of sow

1 egg per estrus

Ovulation rate of Mare

Approx. 28 eggs per month

Ovulation rate of Hen

calving

Reproductive act of cows

calf

Offspring of cows

lambing

Reproductive act of ewes

lamb

Offspring of ewes

farrowing

Reproductive act of sows

pig

Offspring of sows

hatching

Reproductive act of hens

chick

offspring of hens

foaling

Reproductive act of mares

foal

offspring of mares

kidding

reproductive act of goats

kid

offspring of goats

275-285 days

Gestation period of cow

142-150 days

Gestation period of ewe

112-114 days

Gestation period of sow

330-345 days

Gestation period of mare

270 days

Gestation period of woman

310-320 days

Gestation period of caracow

150 days

Gestation period of doe

180-270 days

Lactation period of beef

• 305-365 days

• 60-120 days

• 21-42 days

• 90-150 days

• ? years

Lactation period of dairy

200-300 days

Lactation period of river

• 340 days

• 30-60 days

Lactation period of swamp