lecture i ans 416
TRANSCRIPT
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LECTURE I
ANS 416
ANIMAL BIOTECHNOLOGY
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Course Outline
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ANS 416: Animal Biotechnology
Definition of biotechnology; use of biotechnology in reproduction;
artificial insemination, embryo transfer; cloning and its concepts;
transgenic animals and their value; conservation of genetic
materials; biotechnology in animal nutrition: Types of rumenmicroflora, modification of rumen microflora through nutrition and
biotechnology; probiotics and enzymes; metabolic modifiers:
types (e.g. somatotropins, bovine placental lactogen, conjugated
linoleic acid) and effect on animal performance and quality of
food products (e.g. designer eggs); chelation and utilization of
inorganic elements; biotechnology and animal health; vaccines;
oligosaccharides and competitive inhibition; safety and ethical
issues in animal biotechnology; patenting issues.
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Definition of Biotechnology
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While biotechnology has been defined in many forms in essence it
implies the use of microbial, animal or plant cells or enzymes tosynthesise, break down or transform materials.
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Biotechnology is MULTIDISPLINARY industry
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USE OF TECHNOLOGY IN
ANIMAL PRODUCTION
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Somatic
cell culture
Nuclear transfer
(cloning)
Vaccines
Hybridomas
ProbesMonoclonals
diagnostics
Artificialinsemination
Probiotics
Enzymes / hormones
Growth
promotion
Unlimitedasexual multiplication
QuickTim e a nda TIFF(Uncompressed) decompressor areneededt oseethispicture.
Limited
asexual multiplication
Altered
properties
Micro-injection
Transgenic embryo
Re
combinant
DNA
Animal Biotechnology
In vitro
fertilisation
Embryo transfer
SuperovulationOocytes
Deep freezing
Embryo splittingIn vitro embryo culture
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Artificial insemination?
Artificial insemination is the placing of semen inthe female reproductive tract by
artificial techniques.
The use of this technique has
increased over the past several years
due to advancements in
technology.
The process varies by species, but it typically
involves specialized equipment and a trained
technician.
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Steps involved in artificial insemination?
The technician deposits a prepared unit of semen
into the reproductive tract of the female at a
predetermined time.
The objective of artificial insemination is to deposit
the semen at the appropriate time to achievefertilization.
Timing varies by species of animal and should be
closely studied prior to implementing artificialinsemination.
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There are several different segments that support
the process of artificial insemination.
Some of the major segments include:
A. Semen CollectionArtificial insemination
requires that semen be collected from the male.
Semen may be collected via manual stimulation or
theuse of an artificial vagina.
The technique used depends on the species from whichthe semen is being collected.
A. Semen Collect ion
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B. Semen evaluationAfter semen is
collected from the male, it
is evaluated for quality.
Only the highest quality
semen is utilized for
artificial insemination.
The semen must be evaluated under amicroscope to verify that it contains an
appropriate number of living sperm cells.
If approved for use, the sperm is then
processed to increase utilization.
B. Semen evaluat ion
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C. Semen extension
Semen is extended during theprocessing phase, which allows for a singlecollection to be divided into many units.
Only one unit is required for artificial insemination; byextending it, the semen can be used for severalbreedings.
To extend semen, specialized compounds are added to
enhance the viability and storage of the sperm cells. Depending on the species, often nutrients are added to
expand the mass of each semen unit.
C. Semen extension
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D. Semen storage
Semen is stored in one of
two ways.
It is either frozen to extremely low temperatures or
maintained fresh until use.
How semen is stored depends on the species.
For example, cattle semen is slowly cooled and frozen
at a temperature of320F (196C).
Liquid nitrogen is used to obtain these extremetemperatures. Properly frozen and stored semen canremain viable and be used 30 to 40 years later.
The frozen semen is thawed prior to use in a 95 to
98F (33 to 34C) water bath.
D. Semen sto rage
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E. Sexing semen
X-chromosome-bearing bull sperm (which lead to females) have
about 4% more DNA than Y-chromosome-bearing ones (whichlead to males). By placing sperm in a solution of DNA-binding dye,
X-chromosome-bearing sperm become more brightly stained than
Y-chromosome-bearing sperm. By use of lasers plus a device
called a cell sorter, it is possible to separate the sperm into threetest tubes, male, female, and unsexable (the great majority).
Those in the sexed test tubes accumulate at about 1,000 sperm
per second, with an accuracy of just over 80%.
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+ -+-
LASER
900
X sortY sort
Sperm
Stained
With DNA
SensitiveFluorescent
Dye
Flow Cytometer Separation of X and Y Sperm
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Advantages of AI
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Disadvantages of AI
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EMBRYO TRANSFER
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Embryonic stages
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Early stages of mammalian embryo developmen
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What is embryotransfer?
Embryo Transfer This procedure is when an
embryo in its early development is
transferred from its own mother to a recipient
mother.
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Embryo Transfer
Genetic progress is achieved fairly quickly than with
artificial insemination.
AI limits progress to male side of genetic
contribution
Embryo transfer allows each a cow to produce many
offspring and offers more rapid genetic gain.
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How is embryo transfer done?
1. The process of cattle embryo transfer begins by selecting
a genetically outstanding, well-nourished, non-pregnantembryo donor (heifer or cow). At the same time, 10 to15 non-pregnant females (embryo recipients) areidentified.
2. Super ovulation
The donor cow is super ovulated byusing injectable hormones. An average donor cowproduces 6 transferable embryos. However 0-25embryos can be expected.
3. Insemination
Cattle that are super ovulated are heatdetected and inseminated at both 12 and 24 hours afterheat with two straws of semen.
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4. After 7 days, the embryos have developed into atransferable state.
5. When the 7 days are up, a special solution is pushed intothe reproductive tract of the donor and the embryos arewashed out of her.
6. The solution that comes out of the tract is taken into alaboratory and searched for embryos.
7. The embryos can be freshly transferred into another cow
that is in the same part of her cycle as the donor or, theycan be frozen.
How is embryo transfer done (2)
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Artificial
insemination
Embryo transfer : common practice
Donorfemale
Recipientfemale
Superovulation(PMSG and/or FSH)
Induction of oestrus(PGF2a)
Selection
Manipulation
Cryopreservation
Embryo placementEmbryo collection
- surgical (sheep)
- non-surgical (cattle)
Synchronized
1 x 100 x
PMSG: PregnantMare Serum
Gonadotropin
FSH: Follicle stimulating hormonePGF: Prostaglandin F
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ET -
Scheme
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Stimulating Follicular Development
Estrus
Estrus
eCG or
FSH
ProgesteroneFrom C.L.
First FollicularWave
10-12
Multiple
Ovulations
PGF2a
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Foley catheter
Straw (0.25 ml)
Embryo collection
Cryopreservation
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What are the benefits of embryo transfer?
To produce more offspring from a valuable dam.
Some infertility problems can be avoided.
Prevents disease transmission.
Reproduce some endangered species faster thannormally possible.
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What are the limitations of embryo transfer?
Decreases genetic diversity
Decreased diversity often leads to mutations
Expensive and time consuming procedure
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Embryo Transfer
Who is this practical for?
Seed stock producers
An animal of genetic superiority whose offspring is demanded
by the industry.
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Course Outline
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ANS 416: Animal Biotechnology
Definition of biotechnology; use of biotechnology in
reproduction; artificial insemination, embryo transfer;
cloning and its concepts; transgenic animals and their value;
conservation of genetic materials; biotechnology in animal
nutrition: Types of rumen microflora, modification of rumenmicroflora through nutrition and biotechnology; probiotics and
enzymes; metabolic modifiers: types (e.g. somatotropins, bovine
placental lactogen, conjugated linoleic acid) and effect on animal
performance and quality of food products (e.g. designer eggs);chelation and utilization of inorganic elements; biotechnology and
animal health; vaccines; oligosaccharides and competitive
inhibition; safety and ethical issues in animal biotechnology;
patenting issues.