Transcript E- Reproduction and Genetics

Reproduction and Genetics
Reproductive Management Terms
Castration: removing the
testicles of male animals to
prevent breeding
Colostrum: the first milk
produced after a mammal
gives birth
Reproductive Management Terms
Estrus: the time a female
animal is receptive to be
bred, also called heat
Gestation: the time an
animal is pregnant
Reproductive Management Terms
Lactation: the period of time
that milk is secreted by the
mammary glands
Parturition: the act of giving
birth by female mammals
Types of breeding systems
Purebred breeding: a
registered purebred male
and female of the same
breed
Example: Angus x Angus
Types of breeding systems
Crossbreeding: mating a male
and female of different breeds
Examples: Angus x Hereford=
crossbred calf;
Crossbred x
Purebred=crossbred;
crossbred x crossbred=
crossbred
Types of breeding systems
Inbreeding: mating closely
related animals
Examples: brother x sister
Son x mother
Father x daughter
Types of breeding systems
Linebreeding: breeding more
distant relatives than
inbreeding, and can be
traced back to one common
ancestor
Example: cousin x cousin
Types of breeding systems
Grading up: mating purebred
males (sires) to grade or
unregistered or crossbred
females (dams) to improve the
herd
Example: Yorkshire boar x
Yorkshire-Hampshire sow
Types of breeding systems
Hybrid vigor: the superior
traits that come from
crossbreeding causing the
offspring to have traits
better than either parent
Parts of the female
reproductive system
http://mail.fkchs.sad27.k12.me.us
/fkchs/vpig/rep_fml.htm
Parts of the female
reproductive system
Ovaries: two organs located
near the end of the
reproductive tract inside
the body cavity
Produce ova called eggs
Parts of the female
reproductive system
Oviducts: two tubes that carry
the eggs from the ovaries to
the uterus and are also called
fallopian tubes
Tubes that are near but not
attached to ovaries
Parts of the female
reproductive system
Infundibulum: funnel-shaped
end of each oviduct near the
ovary
Picks up eggs at ovulation and
directs eggs into the oviduct
Parts of the female
reproductive system
Uterus: also called womb,
place where fetus grows
Organ with two branched
horn-shaped attachments, if
pregnant will have fetus
inside
Parts of the female
reproductive system
Cervix: neck of uterus, which
separates the uterus from the
vagina
Serves as a passageway for
sperm to travel from the vagina
to the uterus and also seals the
uterus during pregnancy
Thick walled made up of several
folds and rings of muscle tissue
Parts of the female
reproductive system
Vagina: connects the vulva to
the cervix
Receives the male penis and
sperm at copulation, serves as
a passageway for the fetus to
pass through at birth
Parts of the female
reproductive system
Vulva: external opening
Made up of folds of skin
Parts of the male
reproductive system
Scrotum: saclike part that
holds testicles
Protects testicles
Located externally
Parts of the male
reproductive system
Testes or testicles: two oval
structures inside scrotum in
livestock and inside body cavity
of poultry on each side of
backbone
Produce sperm and male sex
hormones (testosterone)
Parts of the male
reproductive system
Epididymis: long coiled tube
connected to each testicle
Stores sperm while they
mature
Parts of the male
reproductive system
Accessory glands: Seminal
vesicles, prostate gland,
Cowper’s gland
Produces fluids to protect and
carry sperm
Located between kidney and
urethra
Parts of the male
reproductive system
Seminal vesicles: open into
urethra
Prostate: near the urethra
and bladder
Cowper’s: near urethra
Parts of the male
reproductive system
Penis: covered by sheath, part
that penetrates female at
breeding
Deposits semen (papilla in
poultry)
Rod-like tissue inside sheath
Parts of the male
reproductive system
Sheath: protects the penis
from injury
Skin that covers the penis
Parts of the male
reproductive system
Testicles are removed by
castration to keep males
from breeding
Papilla is organ in poultry’s
cloaca that puts sperm in
female hen’s repro tract
Poultry reproductive system
The major difference from
mammals is the embryo
develops outside the body in
poultry.
Birds only have the left ovary
and oviduct at maturity
Poultry reproductive system
The ovary produces ova
(eggs) and hormones
Yolk-ovum
Oviduct has 5 parts-vagina,
uterus, isthmus, magnum,
and infundibulum
Poultry reproductive system
The vent is the outside
opening
Uterus and vagina are part
of the egg production and
egg laying process
Female poultry repro
Ovary- produces ova or yolks
and hormones
Part where yellow, round egg
yolks of different sizes are
attached
Female poultry repro
Infundibulum- the place
where fertilization takes
place
Funnel shaped end of
oviduct
Female poultry repro
Magnum- secretes the thick
egg white or albumen
Isthmus- adds the two shell
membranes
Uterus- secretes the thin
white, the shell and the shell
pigment
Female poultry repro
Vagina- holds the egg until it
is laid
Cloaca- egg passes through,
semen is deposited here
during breeding
Just inside the vent
Female poultry repro
http://ww
w.ahsc.ariz
ona.edu/ua
c/iacuc/po
ultry/speci
es.shtml
Female poultry repro
Vent- place where eggs pass
out of the hen’s body (outside
opening)
Egg- Function is repro but is
eaten as food
Incubation for chicken eggs is
21 days
Male poultry repro
Papilla- deposits semen
Cloaca- just inside the vent
Testes- two parts inside the
abdominal cavity with one on
each side of the backbone
Male poultry repro
http://www.ahsc.arizona.
edu/uac/iacuc/poultry/s
pecies.shtml
The Cell
Body is made up of millions of
tiny structural units called
cells
Cell Parts
Nucleus- gives cell ability to
grow, to digest food and to
divide, contains
chromosomes composed of
genes
Cell Parts
Cytoplasm- gives the cell
shape and contains
components necessary for
cell functions
Cell membrane- outside of
cell
The Cell
http://
www.enc
hantedl
earning.
com/su
bjects/
animals/
cell/
Cell Division
Mitosis- type of cell division
that increases the total
number of cells
Results in animal growth with
the chromosome pairs being
duplicated in each new cell
Mitosis
http://ww
w.enchant
edlearning
.com/subj
ects/anim
als/cell/m
itosis/lab
el/
Cell Division
Meiosis: type of cell division
that produces the sex cells
or gametes that have ½ the
number of chromosomes
that body cells have
Chromosomes
Rod shaped bodies (in pairs)
Cattle: 30 pairs
Hogs: 19 pairs
Chickens: 39 pairs
Chromosomes
http://ww
w.patholog
y.washingt
on.edu/gall
eries/Cyto
gallery/cy
togallery.h
tml
Genes
Located on chromosomes, control
characteristics that are inherited
from parents
Dominant- hides the effect of
recessive genes (covers recessive)
Recessive-covered but can show up
when heterozygous pairs combine
(Pp x Pp- calf with horns)
Heritability
Likelihood of a trait being
passed on from parent to
offspring
Low heritability –slow
High heritability-faster
Heritability
Estimates are usually higher in
beef cattle than in swine
Range from 0% to 70%
Low estimates- improve through
environment
High- selective breeding and
environmental improvements
THE END