Various contentions have been put forward in the dog world by some, (eg those against mixed breeds), that 'hybrid vigor' is allegedly not possible (for example) when breeding Labradoodles (ie mixed breeding of Labradors and Poodles) as it is alleged that hybrid vigor is only possible with mixed breeding of unrelated animals (eg horse and donkey). However, that it not correct. For example, see http://www.ermanz.govt.nz/resources/publications/pdfs/ER-IS-03-01.pdf:
"What is a hybrid?
A hybrid is an organism resulting from a cross between genetically different parents. Hybrids can arise from crosses between closely related species (interspecific hybrids) or by crosses between different types (subspecies, varieties, cultivars) within a species (intraspecific hybrids).
Hybridisation occurs naturally, but it is also widely used in selective breeding programmes for both plants and animals. The mule is an interspecific hybrid between the horse and the donkey, bred to combine some of the favourable characteristics of each parent. Intraspecific hybrids often show 'hybrid vigour' (heterosis), growing more vigorously and yielding more than in-bredlines."
Hence, Labradoodles are 'intraspecific hybrids' (ie are within species breeding) and do show hybrid vigor.
Also, see http://www.country-wide.co.nz/article/449.html:
Another important but often forgotten principle is what happens when you interbreed the first cross (F1) progeny. In essence if you breed (F1) sires and dams together, there will be less hybrid vigour in the progeny. Like wise hybrid vigour also drops if you breed back to either of the parent breeds.
Our Labradoodle puppies are F1 generation (ie first cross between Labrador & Poodle), maximising hybrid vigor (or heterosis), and minimising inbreeding depression, etc. And have purebred parents with champion bloodlines/pedigrees.
The F1 (ie first generation) of Labradoodle puppies have more hybrid vigor than the second or so generation, are less likely to be more variable then some other generations, and also have the least inbreeding depression.
Another interesting scientific point to note about our F1 Labradoodles is that research has shown that these have increased longevity or rates of survival (eg research has shown up to 4 years longer), due to the absence of inbreeding (such as that occuring in purebred dogs). And the same research has shown that the higher the rate of inbreeding (eg in purebreds), the lower or shorter the longevity or survival rates. This relates to the term known as 'inbreeding depression', and which is described in more detail at inbreeding depression and inbreeding depression.
And this may be due to the benefits from hybrid vigour, especially compared to the negative effects known as 'inbreeding depression' present in purebreds.
Unlike some breeders, we can guarantee the genetics of the puppies are solely Labrador/Poodle, as the parents of our Labradoodle puppies are purebred, and with pedigree papers. And this also ensures that they are definitely F1 puppies.
The term 'hybrid vigor' is used in various fields, such as breeding livestock, rabbits, aquaculture, plants, cats, dogs, etc.
And rather than just us giving you our opinion etc re hybrid vigor, we thought you may like to read information from other sources. So that you can make an informed choice or decision.
So, below are some relevant extracts re hybrid vigor, and links to their sources (as at 3/11/05).
From MSN encarta online:
'hybrid vigor
improved traits resulting from crossbreeding: the increased growth, disease resistance, or fertility seen in hybrid species.'
From Encylopedia Brittanica online:
'Increase in such characteristics as size, growth rate, fertility, and yield of a hybrid organism over those of its parents.'
'Plant and animal breeders exploit heterosis by mating two different purebred lines that have desirable traits. The first-generation offspring generally show, in greater measure, the desired characteristics of both parents. Since this vigour may decrease if the hybrids are actually mated together, the parental lines must be maintained and crossed for each new crop or group desired.'
From Merriam-Webster Online Dictionary:
'heterosis
the marked vigor or capacity for growth often exhibited by crossbred animals or plants -- called also hybrid vigor'
From report by CSIRO:
"The benefits of hybrid vigor only appear in crossbred animals that have parents of completely different breeds."
From a transcript of the Senate:
"veterinarians recognize the concept of 'hybrid vigor', especially in first generation hybrids"
From United States Department of Agriculture, University of Arkansas, and County Governments Cooperating:
"The highest level of hybrid vigor is obtained from F1's, the first cross of unrelated populations."
"Hybrid Vigor - An increase in the performance of crossbred animals over that of purebreds, also known as heterosis."
So, there should be little (if any) doubt that the first generation (ie F1) Labradoodles have the maximum hybrid vigor and the least inbreeding depression compared to other generations etc.
