Breeding for colour

[BarbedWire]

I guess this is something that is already known.

 

https://www.abc.net.au/news/2018-10-23/chocolate-labradors-die-earlier-than-yellow-and-black/10418110

 

Chocolate labradors die earlier than yellow and black counterparts, study finds

Updated 23 minutes ago

PHOTO: The study looked at more than 33,000 labradors in the UK. (Supplied: Dogs 4 Independence)

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If you own a chocolate-coloured labrador, chances are it will not live as long as its yellow and black cousins, a new study has shown.

Key points:

• The median life expectancy for a chocolate labrador is 10.7 years, but 12.1 years for a non-chocolate lab
• Skin disease and ear infections are also more common in chocolate labradors
• Labradors of all colours are among the most obese breeds

 

Research led by the University of Sydney found the life expectancy of chocolate labradors was significantly lower than their black and yellow cousins.

It also found skin diseases and ear infections were more common.

The study — which was part of the university's VetCompass program — looked at more than 33,000 labradors in the United Kingdom to get a better insight into their health and life expectancy.

Data was extracted on death and disease from a random sample of 2,074 labradors, about 6.2 per cent of the dogs.

Lead author of the study Professor Paul McGreevy told ABC Radio Adelaide that the findings were surprising.

"The main reason we did the study was to find out what diseases they get … so that we can help breeders prioritise any breeding initiatives to get rid of inherited disorders," Professor McGreevy said.

"It was a surprise to find that these chocolate labs are dying 10 per cent earlier than the yellow and black [labradors]."

The study found that in the UK, the median longevity of non-chocolate labradors was 12.1 years, where as chocolate labradors was 10.7 years.

Labradors are one of the most popular breeds of dog in the UK, and Professor McGreevy said he could not confirm whether the longevity rate would be the same in Australia.

PHOTO: Labradors are one of the most popular breeds of dog. (ABC News: Mark Reddie)

 

Focus on colour, not on health

Professor McGreevy said researchers believed the difference in life expectancy was related to therecessive gene needed to breed chocolate labradors.

He said breeding from a smaller gene pool came with additional risks of health problems and disease for the popular pooch.

"We think it may be to do with their disease burden, they seem to have more skin and ear disease, in fact they get twice as many ear infections and four times as many skin infections," he said.

"The chocolate gene is a recessive gene, so years ago … they were actually used for hunting and for retrieving, they didn't actually use the chocolate [labradors] for some reason.

"This is a recessive gene that people have quite rightly found very appealing and obviously there has been a demand for it.

"But you have to breed from dogs that carry the gene, both parents have to carry the gene to have chocolate puppies.

"We may have taken our eye off some of the health [issues] and instead focused on colour."

Obesity remains a big problem

In 2016 it was found that labradors topped obesity charts in studies and surveys across the US, UK and in Australia.

PHOTO: The study found that obesity remained a big problem for labradors. (ABC News: Ian Cutmore)

 

Professor McGreevy said his study had found similar results.

He said that osteoarthritis was common in the breed which did not surprise him, as labradors could easily put on weight.

The personality of the breed was also mentioned, however Professor McGreevy said more research was needed to find out if coat colour had an impact.

He said he hoped researchers would one day join the dots and work out if behaviour was determined by the coat colour.

"We are very interested in the behaviour of dogs … [chocolate labradors] have got a different retina to the yellow and black labs, very few people appreciate that," he said.

"We don't know how that affects their behaviour but they are looking at the world through different eyes so we would expect some behavioural differences to be found."

[cannibalgoldfish]

Eye color affects behaviour? 

[RuralPug]

34 minutes ago, cannibalgoldfish said:

Eye color affects behaviour? 

To be fair they actually said the retina was different, not that it just was a different colour.
However I tend to agree with your point, I really don't see how a differently structured retina would affect behaviour either.

Now if their scenting ability was structured differently I WOULD expect that to affect their behaviour as that sense uses a much bigger portion of the dog brain than does sight.

[sandgrubber]

I have 3 chocolate Labs, aged 14 (probably won't make 15), 9 (acts middle aged) and 5 (acts like a puppy).   Grand dam, dam and pup. I don't dispute the findings, but it ain't necessarily so.  The problem is poor breeding, not colour per se. 

[RuralPug]

5 hours ago, sandgrubber said:

I have 3 chocolate Labs, aged 14 (probably won't make 15), 9 (acts middle aged) and 5 (acts like a puppy).   Grand dam, dam and pup. I don't dispute the findings, but it ain't necessarily so.  The problem is poor breeding, not colour per se. 

Agreed - in breeding FOR colour first and foremost, health problems in the breeding stock are overlooked in favour of colour. We see the same problem currently in blue SBTs and in other "fashionable" colours in other breeds.

It is not impossible to find a healthy specimen of "colour" but they are more likely to be healthy if one or both parents is a different colour - nothing to do with the actual colour, a lot to do with the focus of breeding.

[asal]

Kind of ignored the fact that cream is RECESSIVE to black?

Recessive does not mean diseased.

Blue eyes are Recessive to brown eyes, haven't heard of blue eyes being associated with disease yet , well so far.

Had chocolate chihuahua's for decades many long outlived their black and gold littermates?

Never had an obesity problem, (unless we're overfed) either. Applied to all colours, although pearl got fat looking at food, but she was copper gold?

Edited October 29, 2018 by asal

[YOLO]

Well yes, what the article mentions, but should emphasise is that it is the inbreeding causing the problems, not the colour itself.
Whilst always a problem when trying to breed specifically for colour, its compound with Labs, because breeders will usually only breed Chocolates with another chocolate or pure Black.    (Mixing Chocolate and Golden lines can produce Dudleys)

[asal]

Wonder what they make of weimariners?

The entire breed is blue with many both double blue AND double chocolate.

Inbreeding is the crossing of close relatives not the breeding of two unrelated blues or chocolate.

Yet I have never seen one with blue gene alopecia, why because to happen there has to be the faulty Elle present, the old breeders eliminated it without the aid of DNA testing

Edited October 30, 2018 by asal

[sandgrubber]

1 hour ago, Big D said:

Well yes, what the article mentions, but should emphasise is that it is the inbreeding causing the problems, not the colour itself.
Whilst always a problem when trying to breed specifically for colour, its compound with Labs, because breeders will usually only breed Chocolates with another chocolate or pure Black.    (Mixing Chocolate and Golden lines can produce Dudleys)

Can you provide any evidence of this? My first chocos was a surprise from a black x yellow mating.  When I bred her, I preferred (not strongly, but there's such a wide selection of Labs at stud, even a weak preference can be followed without sacrifice) black carrying both yellow and chocos... rainbow litters are the best if you aren't concerned about color and expect puppy buyers to have color in mind. Show oriented people don't want dudleys, but most lab pups go to pet homes, and the only thing wrong with a dudleys is some idiotic words in the breed standard that disqualifies them in the ring. 

[asal]

Inbreeding is the favourite excuse for when something went wrong, even if it's parents are completely unrelated.

Instead of the fact no matter how inbred the parents a faulty gene cannot be passed on if they don't carry it.

Likewise outcrossing will still express a fault if both carry it to pass on regardless of there being no inbreeding .

It's the favourite blame game word today.

Hestia was the result of four half siblings, all had the same sire, Shahzada, some Arabians have 27 and more crosses to him. Hestia did not carry SCIDS nor any of the inbred to Shahzada horses.

It took Sala, Razaz and later imports to introduce that lethal into Australia.

Two SCIDS genes the baby has no immunity, it's the same gene "the boy in the plastic bubble" had. Only a bone marrow transplant can save them.

Edited October 30, 2018 by asal

[asal]

Inbreeding did not create the HYPP gene in Impressive, he carried the first mutation.

 

[YOLO]

Simple fact is that breeding from an arbitrarily reduced gene-pool is BAD.  period.

Then if you are able to genetically screen, infinitely better to screen for genetic deficiencies rather than colour.
No dog is perfect, so chances are if you focus on colour it may be to the detriment of something else.

[sandgrubber]

On 11/2/2018 at 7:32 AM, Big D said:

Simple fact is that breeding from an arbitrarily reduced gene-pool is BAD.  period.

Then if you are able to genetically screen, infinitely better to screen for genetic deficiencies rather than colour.
No dog is perfect, so chances are if you focus on colour it may be to the detriment of something else.

I'd hesitate to make much of this in the case of Lab colors because 

1. All closed registries are arbitrarily reduced gene pools.  

2. Genetic exchange between chocolate Labs and yellow and black Labs is not highly, restricted... and for many breeds the total breed population is MUCH smaller than the population of chocolate Labs. 

[DogsAndTheMob]

I think the news report is misleading. The research report published in Canine Genetics and Epidemiology indicates that the longevity of 139 non-chocolate labs was compared with that of 34 chocolate labs. This is vastly different from a study of 33,000 dogs, or even the 2,074 dogs for whom “disorder and mortality data” was extracted!

https://cgejournal.biomedcentral.com/articles/10.1186/s40575-018-0064-x