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WHEN IS COI TOO HIGH IN A KENNEL?

What Does the COI Number Tell You?

 

Understanding the Coefficient of Inbreeding

The coefficient of inbreeding is the probability of inheriting two copies of the same allele from an ancestor that occurs on both sides of the pedigree. These alleles are "identical by descent". The inbreeding coefficient is also the fraction of all of the genes of an animal that are homozygous (two copies of the same allele). So, for a mating that would result in offspring with an inbreeding coefficient of 10%, there is a one in 10 chance that any particular locus would have two copies of the same allele, and 10% of all of the genes in an animal will be homozygous.

 

Beuchat, C. PhD. (6/4/2015). COI FAQS: Understanding the Coefficient of Inbreeding. Retrieved on January 16/2017 @  http://www.instituteofcaninebiology.org/blog/coi-faqs-understanding-the-coefficient-of-inbreeding

 

The Results from One Havanese Kennel in Canada

 

The following two charts with statistics have been taken from data included in the CKC Havanese Studbooks from 2011-2015. Two exceptions are the first two litters from 2010; these were litters posted on Havanese Gallery and included in the data to indicate trends.

 

The cumulative 29 litters indicate the COI of all offspring from one Canadian Havanese Kennel registered with the CKC during the period under investigation.

 

Please note:

  • The first 2 litters from 2010, 4/4/2010 and 6/12/2010, were recorded on Havanese Gallery. These 2 litters were included to show trends that were occurring. (It is likely that both litters are recorded in the 2010 CKC Studbook which is not part of this study as yet.)

  • Two litters from 2010 registered in the 2011 CKC Studbook have also been included: 11/23/2010 and 11/28/2010.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Please note:

 

All COI have been calculated back to the Founder.

 

Calculating COI

...You need ALL of the ancestors of a dog to be in the pedigree database you use, and for purebred dogs this means a pedigree database that goes back to the first registered dogs in the breed - the founders. 

 

Beuchat, C. Ph.D.  (6/4/2015). COI FAQS: Understanding the Coefficient of Inbreeding. Retrieved on January 16/2017 @  http://www.instituteofcaninebiology.org/blog/coi-faqs-understanding-the-coefficient-of-inbreeding

 

What COI is “too high”

 

Understanding the Coefficient of Inbreeding

In terms of health, a COI less than 5% is definitely best. Above that, there are detrimental effects and risks, and the breeder needs to weigh these against whatever benefit is expected to gained. Inbreeding levels of 5-10% will have modest detrimental effects on the offspring. Inbreeding levels above 10% will have significant effects not just on the quality of the offspring, but there will also be detrimental effects on the breed.

 

For comparison, mating of first cousins produces a COI of 6.25%; in many societies this is considered incest and is forbidden by law). Mating of half-siblings produces a COI of 12.5%; mating of full siblings produces a COI of 25%

 

Beuchat, C. Ph.D.  (6/4/2015). COI FAQS: Understanding the Coefficient of Inbreeding. Retrieved on January 16/2017 @  http://www.instituteofcaninebiology.org/blog/coi-faqs-understanding-the-coefficient-of-inbreeding

 

  • The lowest COI is 16.95% found in the litter born on 1/26/2012.

  • The highest COI is 31.93% found in two litters born 10/20/2013 and 8/24/2014.

  • The average COI of the 82 offspring from this kennel is: 25.41%.

 

9 Litters for One Dam from 2011-2015

 

The following chart shows that 9 litters were registered to a single dam from this kennel during the period under investigation.

 

Please note:

  • 4/4/2010 litter came from Havanese Gallery.

  • 11/28/2010 litter was registered in the 2011 CKC Studbook.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Repeat Breedings

 

Of the 29 litters noted in this study from this kennel between 2011-2015:

  • 3 bitches were bred X 3 with the same sire

  • five others bitches were bred twice with the same sire.

 

Singletons and Doubletons

 

Of the 27 litters registered from this kennel with the CKC between 2011-2015 and the extended 2 litters from 2010 found on Havanese Gallery, 2 were Singletons and 7 were Doubletons. 

 

Please Note:

The count for the 27 litters in the CKC studbook, have been made according to their original CKC registrations, not the above charts, because sometimes not all pups were registered and/or a pup was registered under a different kennel name.

 

The following article speaks to the issue of COI and small litter sizes:

 

Understanding the Coefficient of Inbreeding

The deleterious effects of inbreeding begin to become evident at a COI of about 5%. At a COI of 10%, there is significant loss of vitality in the offspring as well as an increase in the expression of deleterious recessive mutations. The combined effects of these make 10% the threshold of the "extinction vortex" - the level of inbreeding at which smaller litters, higher mortality, and expression of genetic defects have a negative effect on the size of the population, and as the population gets smaller the rate of inbreeding goes up, resulting in a negative feedback loop that eventually drives a population to extinction.

 

Beuchat, C. Ph.D. (6/4/2015). COI FAQS: Understanding the Coefficient of Inbreeding. Retrieved on January 16/2017 @ http://www.instituteofcaninebiology.org/blog/coi-faqs-understanding-the-coefficient-of-inbreeding  

 

 

How One Kennel Has the Potential to Impact

the Genetic Diversity of the Havanese Breed

 

It is one thing to produce puppies with high COI who are not breeding animals who will become pets. It is quite another to sell puppies with a very high COI to other kennels, thus passing along the problem.

 

A quick investigation of the dogs from this kennel posted on Havanese Gallery indicate that 18 dogs either have been or are currently being bred. Four of those dogs are being bred by other breeders in the US, Canada and Poland.

 

The offspring of these 18 breeding dogs, (both from this kennel and the other three kennels now breeding their purchased offspring), have been sold in Canada, USA, Sweden, UK, France, Germany, Lithuania, Australia and Poland. Some of these breeding animals now also have offspring of their own who are breeding.

 

11 of the breeding dogs are males. 

 

One male from this kennel, with a COI of 25.76%, is firmly on his way to becoming a popular sire. This male has sired offspring that can now be found in Canada, France, Poland, USA, Sweden, UK, Germany, Australia and Lithuania. The offspring of this sire do not yet show their own offspring on Havanese Gallery; however, some of his offspring can be found in the KC database. It is possible that others are also producing because their sire was born in 2014.

 

 

What Makes a Popular Sire a Popular Sire? 

 

A sire does not have to sire many litters to be very influential and a male can have countless litters and not be influential at all. What makes a sire influential is how many of his offspring end up in breeding and where they end up breeding.

 

The Pox of the Popular Sire

The really unfortunate thing about the Popular Sire is that the negative genetic consquences of his popularity don't begin to manifest for generations, by which time the breed already has a really significant problem. The large number of breed-specific disorders known to be caused by a single recessive gene (175 as of this writing; OMIA) is testimony to the prevalence of the problem (indeed, some breeds now suffer from multiple recessive genetic disorders).

 

Beuchat, C. Ph.D. The Pox of the Popular Sire. Retrieved on January 16/2017 @  http://www.instituteofcaninebiology.org/the-pox-of-popular-sires.html

 

Breeders Buying Breeding Animals with Extremely High COI 

 

Another thing to consider, when breeders buy pups from such litters, they too are responsible for making the breeding pool of the Havanese shallower. As Senija Hodzic indicates, “We are all in it together.”

 

Carol Beuchat, PhD, would agree with that position:

 

Understanding the Coefficient of Inbreeding

Avoiding high levels of inbreeding in the first place is much easier than trying to fix things after inbreeding becomes a problem. Breeders should work together to monitor the inbreeding of their breed so they can all benefit from healthier puppies that meet their goals as breeders now and in the future.

 

Beuchat, C. Ph.D. (6/4/2015). COI FAQS: Understanding the Coefficient of Inbreeding. Retrieved on January 16/2017 @  http://www.instituteofcaninebiology.org/blog/coi-faqs-understanding-the-coefficient-of-inbreeding

 

Population Genetics in Practice:
Principles for the Breeder by J. Jeffrey Bragg (copyright 2009) forms the base for the following twenty key elements of a Successful Breeding Program.

 

The highlighted points below made by Bragg are of concern when looking at a quick analysis of the results of 5 years of offspring between 2011-2015 for this one Canadian Kennel taken from the CKC Studbooks and Havanese Gallery.

 

  • Maintain balance of sires and dams

  • Eschew incestuous matings

  • Understand and monitor coefficient of inbreeding

  • Pay attention to the trend in COI

  • Calculate number of unique ancestors

  • Know the genetic load but don't obsess about it

  • Use pedigree analysis

  • Conserve sire and dam-line diversity

  • Practise assortative mating

  • Maintain high generation time

  • Avoid repeat breedings

  • Ensure sibling contribution

  • Monitor fitness indicators

  • Attempt founder balancing

  • Consider outcross matings

  • Monitor population growth

  • Seek balanced traits

  • Avoid unfit breeding stock

  • Avoid reproductive technology

  • Restrict artificial selection

 

Beuchat, C. Ph.D. Taken from:  Population Genetics in Practice:
Principles for the Breeder by J. Jeffrey Bragg (copyright 2009). Retrieved on January 16/2017 @  http://www.instituteofcaninebiology.org/blog/twenty-key-elements-of-a-successful-breeding-program

 

 

References

 

Beuchat, C. Ph.D. (6/4/2015). COI FAQS: Understanding the Coefficient of Inbreeding. Retrieved on January 16/2017 @  http://www.instituteofcaninebiology.org/blog/coi-faqs-understanding-the-coefficient-of-inbreeding

 

Beuchat, C. Ph.D. Taken from:  Population Genetics in Practice:
Principles for the Breeder by J. Jeffrey Bragg (copyright 2009). Retrieved on January 16/2017 @  http://www.instituteofcaninebiology.org/blog/twenty-key-elements-of-a-successful-breeding-program

 

Beuchat, C. Ph.D. The Pox of the Popular Sire. Retrieved on January 16/2017 @  http://www.instituteofcaninebiology.org/the-pox-of-popular-sires.html

 

Canadian Kennel Club. (2012). Litter's registered in 2011. CKC: Etobicoke, ON, CA  

 

Canadian Kennel Club. (2013). Litter's registered in 2012. CKC: Etobicoke, ON, CA    

 

Canadian Kennel Club. (2014). Litter's registered in 2013. CKC: Etobicoke, ON, CA  

              

Canadian Kennel Club. (2015). Litter's registered in 2014. CKC: Etobicoke, ON, CA  

               

Canadian Kennel Club. (2016). Litter's registered in 2015. CKC: Etobicoke, ON, CA   

 

Havanese Gallery http://www.havanesegallery.hu/index_en.php

 

 

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