Biotech in Animal Reproduction

Terms

Artificial Insemination The deposition of spermatozoa in the female by

artificial meansSperm

The male sex cell, produced by the testesSemen

A fluid substance produced by the male reproductive system containing spermatozoa suspended in secretions of the accessory glands

Terms

Sire The male parent

Quarantine Process that requires animals to be kept in isolation

for a period of time to make sure they do not have a disease

Protectant Substance such as glycerin added to semen before it

is frozen

Terms

Estrus The period that a female animal is ready for mating

Artificial Vagina A rigid tube used to collect semen for artificial

inseminationEjaculation

The discharge of semen from the reproductive tract of the male

Terms

Conception The beginning of gestation; when a sperm fertilized an

ovumMotility

Active movement in artificial insemination of the sperm

Extender A substance, such a milk, egg yolk, glycerin, or/or

antibiotics, that is added to semen to dilute and protect it

Terms

Straw Small hollow tubes that contain frozen semen

Hormone A chemical substance produced by the body or

introduced into the body to produce a specific effectEstrus Cycle

The reproductive cycle in nonprimates

Terms

Follicle Stimulating Hormone (FSH) A hormone to induce estrus

Follicle A small blisterlike development on the surface of the

ovary that contains the developing ovumEmbryo Transfer

The process of removing an embryo from a superior female and implanting it into an inferior female.

Terms

Dam The female parent

Progeny Testing Test of the value of an individual's genotype by

looking at the progeny produced by different matingsDonor Cow

A cow that is of unusual value as a breeding animal, used for embryos

Terms

Recipient Cow A cow of ordinary value that will be implanted with a

superior female’s embryoSuperovulation

Process of injecting the donor animal with a follicle stimulating hormone which will cause the animal to release several eggs instead of just one

Prostaglandins Hormones that will make a recipient cow come into

estrus

Terms

Corpus Luteum Active tissue that produces progesterone if conception

occurs (Yellow Body)Sperm Sexing

Separating the female (X) cell from the male (Y) cell in order to produce only male or only female offspring

Cytometer Cell Sorter An instrument used to sort (X) sperm from (Y) sperm

according to the amount of light given off by the chromosome

An Overview

Every aspect of the

livestock industry is

dependent on animal

reproduction!!!!

In this chapter: Biotech in animal breeding Advantages of artificial

insemination Process of artificial insemination Semen processing, storage and

shipment Estrus synchronization Egg production Advantages of embryo transfer Process of embryo transfer Advantages of sexed semen Sperm sorting

Artificial Insemination

Artificial Insemination The deposition of spermatozoa in the female by

artificial meansSperm

The male sex cell, produced by the testiclesSemen

A fluid substance produced by the male reproductive system containing spermatozoa suspended in secretions of the accessory glands

Advantages

Use of the highest quality animal availableCost of semen vs whole animalAvailability of records# of offspring (potential for 40,000+ from one

male)Goals & selectability for herd needsFarm safety (No bull/aggressive male)Reduced transmission of disease (genetic &

sexual)No quarantine time on out of country stockReduced sire cost to producersIncreased uniformity

Sire The male parent

Progeny Testing Test of the value of an individual's genotype by

looking at the progeny produced by different matings

Development

As far back as the middle ages Collection of prized enemy stallions

First successful insemination: 1780 Lazarro Spallanzani Dog Little economic value at the time

1st large scale use Russians 1900

Horse repopulation Cattle & Sheep 1920/30s

How it works:

Problems?

Preserving live sperm 2-3 day life span

Freezing! Relatively few sperm survived

ALL HAIL THE 1950s!! Protectant: Substance such as glycerin added to

semen before it is frozen Temperature lowered at a specific rate until -320°F Will remain viable for years (30+!)

Any drawbacks?

Labor intensive! Monitor for estrus Singular restraint & insemination Requires skilled technician

Subject to potential abuse?Accentuate damage of poor sire?Additional capital & managementOthers?

Semen Collection & Processing

Artificial Vagina

A rigid tube used to collect semen for artificial insemination

Extender

A substance, such a milk, egg yolk, glycerin, and/or antibiotics, that is added to semen to dilute, nourish and protect it

Dummy animal & artificial vagina

Sperm examination Number (15,000,000+ = normal) Motility Shape

Add extenders

Volume of Semen and Conc. Per Insemination

*1 cc is the volume of semen contained in each straw of bull and ram semen

Species

Dilution Ratio

Volume/Service

# Sperm/Inseminatio

n

Bull 1:200 .5 cc 15,000,000

Stallion

---- 5-10 cc 250,000,000

Boar 1:8 50-100 cc

2,000,000

Ram 1:1 .5 cc 50,000,000

Semen Collection by Specie

Bull

Boar

Turkey

http://www.youtube.com/watch?v=y6IEk9RNvA4

http://www.youtube.com/watch?v=lzJhhfyoxY0

http://www.youtube.com/watch?v=qgf6h588v-I

Examined and packaged in straws

Stored at -320°F in liquid nitrogen

Thawed immediately before placed in female

Proper temp & speed

Straws:Small hollow tubes that contain frozen semen

Click icon to add picture

When to breed:

Heat Detection

Visible activity: Excitability, restlessness & noisy Attempt to ride other cows Stand to be ridden by other cows

But what if you’re not there? Ruffled hair on tale head High tail head appearance Genital mucus Swollen vulva

Tail chalk, kamars, heat detect systems

*In Cattle

Repro Cycle in Farm Animals

Species

Length of Estrus

Cycle (d)

Length of Estrus

Time of Ovulatio

n

Gestation Length

(d)

Age @ Puberty (m)

Avg. Range

Avg. Range Avg

Range

Mare 21 10-37

5-6 d 1-14 d 24-28 h before end of estrus

336

310-350

10-12

Cow 19-21

16-24

16-20 h

8-30h 10-14h after end of estrus

281

274-291

4-8

Ewe 16 14-20

30 h 20-42h 1 h before end of estrus

150

140-160

4-8

Sow 21 18-24

1-5d 1-5d 18-60h after estrus begins

112

111-115

5-7

Factors for Consideration

Highest conception rates = 60-90 days after calving

Breed from 9 hrs following heat to 24 hrs after heat

Sperm will live about 24 hrs in the female repro tract

True heat is when a cow will stand to be ridden

Fertilization will occur immediately if sperm is present when the egg is released

Think about It:

Discuss how AI might be of economic importance to a livestock producer.

What is the female hormone produced by the ovary that regulates the heat period?

What is parturition?What is semen extender?

Control of the Estrus Cycle

Estrus Cycle

The reproductive cycle in non-primates

Elimination of consistent monitoring

Big savings! Time Labor Costs

Hormone regulation!!

Hormones!!

FSH A hormone to induce estrus & stimulate ovum release

LH Triggers ovulation

Progesterone Produced by CL to maintain pregnancy

Prostaglandin Hormones that will make a recipient cow come into

estrusEstrogen

Released by the follicle; signals heat

In other words:

Organ/SiteHormone Released

Target Site Result

Pituitary Gland FSH OvaryEgg

Mature/Release

Follicle Estrogen Pituitary Gland Heat

Pituitary Gland LH Follicle Ovulation

Corpus Luteum Progesterone UterusMaintains Pregnancy

Follicle Prostaglandin Uterus If not pregnant

Blood Balanced FSH Pituitary Gland Cycle Over

FSH

Stimulates follicleBegin cycle at injectionSynch groups of animals

to ovulate at the same time

SAVES BIG! Resources at breeding Resources at

calving/farrowing Groups of same age animals

Embryo Transfer

http://www.youtube.com/watch?v=hRUJSMfFgfc

Benefits of Embryo Transfer

Advancement of genetics from the damProgeny testing of femalesImport and export without quarantineDual production system (milk & meat)TwinningConversion from grade to

registered/purebred

Disadvantages

Narrowed genetic baseLoss of diversity

Case and point: Guernsey cattle

Selection of donor and recipient cows

Donor depends on: Milking ability Ability to grow Reproductive capacity Show appeal

Recipient depends on: Health Ability to maintain pregnancy Ability to deliver a healthy calf

Donor

A cow that is of unusual value as a breeding animal, used for embryos

Recipient

A cow of ordinary value that will be implanted with a superior female’s embryo

Process of Embryo Transfer

Get them In Synch!

Donor Animals Recipient Animals

Superovulation 12-15 eggs

Inject FSH Several follicles to

shelter growing eggsProstaglandin

Causes estrusInseminationCollection

Grown for ~1 week

Prostaglandin Causes estrus

Monitor CLImplant embryos

In uterus

Not like that!

The Flush!

And not like this either!!!

Or this!!

The REAL Flush!

Long rubber catheter Passed through cervix to uterine horn

Inflatable bulb Seals entrance to the uterus

Solution injection Fill fallopian tubes and uterus

Drainage Solution and eggs drain into collection cylinder

~6 embryos per flush

And afterwards?The uterus is flushed again

with a solution that will kill any

remaining embryos to

prevent infection.

The numbers

Up to 30 embryos could be obtained in one flush (usually 6-7)

Survival to term: 50-70%Superovulated vs non

Non= 5 calves/year Super= 9-12 calves/yearRecovery = 50-90%*

Cattle = 50-80% Horses = 40-90%

*Nonsurgical methods

Think About It

What support technology & procedures are involved in ET?

What are the advantages to embryo transfer?What are the expected result rates of ET?What is superovulation and why is it used?Indicate expected recovery rates concerned

with ET?What is estrus synch?

Sperm Sexing

Why?Depends on industry

Dairy: Females = milk producers Swine: Boar meat = odorous & unacceptable Beef: Males = bull studs for breeding Poultry: Females = layers

Chromosomes

A refresher:

Females have 2 X chromosomes

Males have an X and a Y

When eggs are formed they all have an X

Sex determined by which sperm fertilized the egg

Sperm Sexing

Sperm Sexing:

Separating the female (X) cell from the male (Y) cell in

order to produce only male or only female

offspring

Cytometer Cell Sorter:

An instrument used to sort (X) sperm

from (Y) sperm according to the

amount of light given off by the

chromosome

1989: Method patentedFluorescent dye adheres to

sperm DNA Female chromosome has more

DNA More dye in the female

chromosome (by 2.8-7.5%)!!

And now?

And now?Guarantee

85-95% accuracy (cattle)