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)