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![Page 1: Strategies to maintain genetic diversity in rare breeds of livestock Mark Knauer, PhD North Carolina State University Swine Extension Specialist ALBC 11-8-13.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649cf75503460f949c7521/html5/thumbnails/1.jpg)
Strategies to maintain genetic diversity in rare breeds of livestock
Mark Knauer, PhD
North Carolina State University Swine Extension Specialist
ALBC 11-8-13
![Page 2: Strategies to maintain genetic diversity in rare breeds of livestock Mark Knauer, PhD North Carolina State University Swine Extension Specialist ALBC 11-8-13.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649cf75503460f949c7521/html5/thumbnails/2.jpg)
Why is genetic diversity important?
Genetic diversity and inbreeding are inversely
related
Therefore, we work to keep inbreeding at a
minimum
– What is inbreeding? Mating together animals that are related by ancestry
![Page 3: Strategies to maintain genetic diversity in rare breeds of livestock Mark Knauer, PhD North Carolina State University Swine Extension Specialist ALBC 11-8-13.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649cf75503460f949c7521/html5/thumbnails/3.jpg)
Inbreeding is unfavorable
Impaired reproduction
7.58.08.59.09.5
10.010.5
0 10 20 30 40 50 60Inbreeding of dam, %
litter size
Adapted from Bereskin et al. (1968)
![Page 4: Strategies to maintain genetic diversity in rare breeds of livestock Mark Knauer, PhD North Carolina State University Swine Extension Specialist ALBC 11-8-13.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649cf75503460f949c7521/html5/thumbnails/4.jpg)
Inbreeding is unfavorable Impaired survival
Adapted from Bereskin et al. (1968)
7.58.08.59.09.5
10.010.5
0 10 20 30 40 50 60Inbreeding of litter, %
litter size - birth
litter size - market
![Page 5: Strategies to maintain genetic diversity in rare breeds of livestock Mark Knauer, PhD North Carolina State University Swine Extension Specialist ALBC 11-8-13.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649cf75503460f949c7521/html5/thumbnails/5.jpg)
Inbreeding is unfavorable
Impaired growth performance
Adapted from Bereskin et al. (1968)
232
234
236
238
240
242
0 10 20 30 40 50 60
lb.
Inbreeding of litter, %
weight at 180days of age
![Page 6: Strategies to maintain genetic diversity in rare breeds of livestock Mark Knauer, PhD North Carolina State University Swine Extension Specialist ALBC 11-8-13.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649cf75503460f949c7521/html5/thumbnails/6.jpg)
Inbreeding is unfavorable
Largest reproductive issue
– Getting females bred & continuing the
population
![Page 7: Strategies to maintain genetic diversity in rare breeds of livestock Mark Knauer, PhD North Carolina State University Swine Extension Specialist ALBC 11-8-13.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649cf75503460f949c7521/html5/thumbnails/7.jpg)
Inbreeding is unfavorable
Increased incidence of genetic defects
– hermaphrodites
![Page 9: Strategies to maintain genetic diversity in rare breeds of livestock Mark Knauer, PhD North Carolina State University Swine Extension Specialist ALBC 11-8-13.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649cf75503460f949c7521/html5/thumbnails/9.jpg)
Calculating inbreeding
Where
– t = generation and
– ∆F = 1/2Ne
Where Ne = the effective population size
Ft = 1 – (1 - ∆F)t
![Page 10: Strategies to maintain genetic diversity in rare breeds of livestock Mark Knauer, PhD North Carolina State University Swine Extension Specialist ALBC 11-8-13.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649cf75503460f949c7521/html5/thumbnails/10.jpg)
Maintaining genetic diversity
Reduce the rate of inbreeding
Ft = 1 – (1 - ∆F)t
![Page 11: Strategies to maintain genetic diversity in rare breeds of livestock Mark Knauer, PhD North Carolina State University Swine Extension Specialist ALBC 11-8-13.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649cf75503460f949c7521/html5/thumbnails/11.jpg)
Avoid mating close relatives
Avoid mating – in order of importance
– Parents and offspring
– Full siblings - brothers and sisters
– ½ siblings – ½ brothers and sisters
![Page 13: Strategies to maintain genetic diversity in rare breeds of livestock Mark Knauer, PhD North Carolina State University Swine Extension Specialist ALBC 11-8-13.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649cf75503460f949c7521/html5/thumbnails/13.jpg)
Increase the number of herd sires used
Important to use as many males as possible
Using a couple or several males, instead of
just 1, significantly reduces inbreeding
favorable unfavorable
![Page 14: Strategies to maintain genetic diversity in rare breeds of livestock Mark Knauer, PhD North Carolina State University Swine Extension Specialist ALBC 11-8-13.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649cf75503460f949c7521/html5/thumbnails/14.jpg)
Bring in outside genetics – live animals
![Page 15: Strategies to maintain genetic diversity in rare breeds of livestock Mark Knauer, PhD North Carolina State University Swine Extension Specialist ALBC 11-8-13.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649cf75503460f949c7521/html5/thumbnails/15.jpg)
If boar is too small
– Collect semen off of the sow in heat Inseminate sow with collected semen
– Use a breeding crate
If boar is too big
– Train to mount an AI dummy
– Use a breeding crate
What if your new boar is too large/too small for your females?
![Page 18: Strategies to maintain genetic diversity in rare breeds of livestock Mark Knauer, PhD North Carolina State University Swine Extension Specialist ALBC 11-8-13.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649cf75503460f949c7521/html5/thumbnails/18.jpg)
Bring in outside genetics – semen
![Page 19: Strategies to maintain genetic diversity in rare breeds of livestock Mark Knauer, PhD North Carolina State University Swine Extension Specialist ALBC 11-8-13.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649cf75503460f949c7521/html5/thumbnails/19.jpg)
Develop a grade up program
½ heritage
×
×3/4 heritage
×
×
7/8 heritage
![Page 20: Strategies to maintain genetic diversity in rare breeds of livestock Mark Knauer, PhD North Carolina State University Swine Extension Specialist ALBC 11-8-13.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649cf75503460f949c7521/html5/thumbnails/20.jpg)
Maintaining genetic diversity
Lengthen the generation interval
Ft = 1 – (1 - ∆F)t
![Page 21: Strategies to maintain genetic diversity in rare breeds of livestock Mark Knauer, PhD North Carolina State University Swine Extension Specialist ALBC 11-8-13.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649cf75503460f949c7521/html5/thumbnails/21.jpg)
Generation interval
Where L = generation interval
L = Lm + Lf
2______
__
![Page 22: Strategies to maintain genetic diversity in rare breeds of livestock Mark Knauer, PhD North Carolina State University Swine Extension Specialist ALBC 11-8-13.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649cf75503460f949c7521/html5/thumbnails/22.jpg)
Lengthen the generation interval
Do not keep offspring out of gilt litters
Keep offspring out of old boars and old
sows
![Page 23: Strategies to maintain genetic diversity in rare breeds of livestock Mark Knauer, PhD North Carolina State University Swine Extension Specialist ALBC 11-8-13.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649cf75503460f949c7521/html5/thumbnails/23.jpg)
Keep offspring out of older parents
Age of boar (yr) Age of sow (yr) Generation interval
Scenario 1 2 1 1.5
Scenario 2 5 4 4.5
Rate of inbreeding is 3 times less in scenario 2 vs. 1.
![Page 24: Strategies to maintain genetic diversity in rare breeds of livestock Mark Knauer, PhD North Carolina State University Swine Extension Specialist ALBC 11-8-13.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649cf75503460f949c7521/html5/thumbnails/24.jpg)
Strategies to maintain genetic diversity
Avoid mating close relatives
Increase your population size
Increase the number of males used for breeding
Bring in outside genetics
– Live animal introductions
– Semen
Develop a grade up program
Lengthen the generation interval
![Page 25: Strategies to maintain genetic diversity in rare breeds of livestock Mark Knauer, PhD North Carolina State University Swine Extension Specialist ALBC 11-8-13.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649cf75503460f949c7521/html5/thumbnails/25.jpg)
Thank you all for your hard work!
Maintaining heritage breeds can be
challenging
– Important to maintain the genetic diversity
associated with heritage breeds
![Page 27: Strategies to maintain genetic diversity in rare breeds of livestock Mark Knauer, PhD North Carolina State University Swine Extension Specialist ALBC 11-8-13.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649cf75503460f949c7521/html5/thumbnails/27.jpg)
![Page 28: Strategies to maintain genetic diversity in rare breeds of livestock Mark Knauer, PhD North Carolina State University Swine Extension Specialist ALBC 11-8-13.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649cf75503460f949c7521/html5/thumbnails/28.jpg)
Strategies to reduce inbreeding
Sample outside genetics
– At least once every 3 years
Lengthen your generation interval
– Retain old sows
Avoid mating
– Brothers and sisters
– ½ brothers and sisters
– Parents and siblings
![Page 29: Strategies to maintain genetic diversity in rare breeds of livestock Mark Knauer, PhD North Carolina State University Swine Extension Specialist ALBC 11-8-13.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649cf75503460f949c7521/html5/thumbnails/29.jpg)
Strategies to reduce inbreeding
Sample outside genetics
– At least once every 3 years
Lengthen your generation interval
– Retain old sows
Avoid mating
– Brothers and sisters
– ½ brothers and sisters
– Parents and siblings
![Page 30: Strategies to maintain genetic diversity in rare breeds of livestock Mark Knauer, PhD North Carolina State University Swine Extension Specialist ALBC 11-8-13.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649cf75503460f949c7521/html5/thumbnails/30.jpg)
Strategies to reduce inbreeding
Sample outside genetics
– At least once every 3 years
Lengthen your generation interval
– Retain old sows
Avoid mating
– Brothers and sisters
– ½ brothers and sisters
– Parents and siblings
![Page 31: Strategies to maintain genetic diversity in rare breeds of livestock Mark Knauer, PhD North Carolina State University Swine Extension Specialist ALBC 11-8-13.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649cf75503460f949c7521/html5/thumbnails/31.jpg)
Other benefits of using AI
Genetic improvement
– Only one “best” herd
Genetic cost - may be less expensive to use AI than
maintain a boar
– How many sows do you have?
Increase number of potential matings
– How many of you have had a boar that was too big or too
small to breed a desired female?
![Page 32: Strategies to maintain genetic diversity in rare breeds of livestock Mark Knauer, PhD North Carolina State University Swine Extension Specialist ALBC 11-8-13.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649cf75503460f949c7521/html5/thumbnails/32.jpg)
Other benefits of using AI
Genetic improvement
– Only one “best” herd
Genetic cost - may be less expensive to use AI than
maintain a boar
– How many sows do you have?
Increase number of potential matings
– How many of you have had a boar that was too big or too
small to breed a desired female?
![Page 33: Strategies to maintain genetic diversity in rare breeds of livestock Mark Knauer, PhD North Carolina State University Swine Extension Specialist ALBC 11-8-13.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649cf75503460f949c7521/html5/thumbnails/33.jpg)
Other benefits of using AI
Genetic improvement
– Only one “best” herd
Genetic cost - may be less expensive to use AI than
maintain a boar
– How many sows do you have?
Increase number of potential matings
– How many of you have had a boar that was too big or too
small to breed a desired female?
![Page 34: Strategies to maintain genetic diversity in rare breeds of livestock Mark Knauer, PhD North Carolina State University Swine Extension Specialist ALBC 11-8-13.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649cf75503460f949c7521/html5/thumbnails/34.jpg)
Summary
Multiple potential benefits to adopting AI
– Maintain genetic diversity!
– Genetic improvement
– Reduce genetic cost
– Increase boar usage
You are taking a positive step today towards
the benefits of AI technology
![Page 35: Strategies to maintain genetic diversity in rare breeds of livestock Mark Knauer, PhD North Carolina State University Swine Extension Specialist ALBC 11-8-13.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649cf75503460f949c7521/html5/thumbnails/35.jpg)
Why should you use AI?
1# reason – genetic diversity
Inbreeding causes inbreeding
depression which is characterized by
reduced fitness
![Page 36: Strategies to maintain genetic diversity in rare breeds of livestock Mark Knauer, PhD North Carolina State University Swine Extension Specialist ALBC 11-8-13.](https://reader036.fdocuments.in/reader036/viewer/2022062421/56649cf75503460f949c7521/html5/thumbnails/36.jpg)
Why should you use AI?
Inbreeding - the breeding or mating of
related individuals within a closed group
animals
When is the last time you introduced
outside genetics into your herd?