Dog breeding question

[John Gryphon]

I see a great many litters bred for financial reasons rather than the betterment of the breeds. Very poor quality bitches that should never be bred from have born litters of poor quality pups. These breeders will not have had their bitches checked for hereditary diseases thats for sure.

Hear hear.
I will add that hereditary problems are like hens teeth in the cross breds.

 

[Keith Edmunds]

Hybrid vigor is more about growth and health rather than working ability.
So yes u could get the worst in both breeds but they should still grow quickier and be healthier long term

Thats why an awful lot of meat (beef, or lamb) will come from cross bred stock for that reason, but most UK farmers won't use the X breeds for breeding past the 2nd gen, unless they have formed theyre own 'mini breed', like blue grey cattle or scotch mule sheep, but even scoth mule sheep i can't think of many breeding off them.
And most will keep some pure lines for breeding the replacements breeding stock and X breed wot they sell for fattening/meat

As u have bred a cross breed u tend not to have any inherited diseases even if 1 of the parents carried that disease because the other parent will be guaranteed not to have it if a breed specific disease, but after the 2nd gen these diseases can sneak back in as usually at a basic level u would need the disease gene on both sides of the mating for the pups to be affected.
Breeding 2 different breeds the other side will never be a carrier, but when u get into 2nd gen+ some pups could be carrying genetic defects from both original breeds

In the old days i was told it was illegal to own a cross bred bull and the ministry would come round and kill it if u had 1, and even now u'd only have 1 for bull beef

I agree, Selective breeding and outcrossing are not always the same...but can be, it depends on the objectives of the people creating the breeding plan. Interesting info below......

When a population is small or inbred, it tends to lose genetic diversity. Inbreeding depression is the loss of fitness due to loss of genetic diversity. Inbred strains tend to be homozygous for recessive alleles that are mildly harmful (or produce a trait that is undesirable from the standpoint of the breeder). Heterosis or hybrid vigor, on the other hand, is the tendency of outbred strains to exceed both inbred parents in fitness.

Selective breeding of plants and animals, including hybridization, began long before there was an understanding of underlying scientific principles. In the early 20th century, after Mendel's laws came to be understood and accepted, geneticists undertook to explain the superior vigor of many plant hybrids. Two competing hypotheses, which are not mutually exclusive, were developed:[3]


Genetic basis of heterosis. Dominance hypothesis. Scenario A. Fewer genes are under-expressed in the homozygous individual. Gene expression in the offspring is equal to the expression of the fittest parent. Overdominance hypothesis. Scenario B. Over-expression of certain genes in the heterozygous offspring. (The size of the circle depicts the expression level of gene A)

• Dominance hypothesis. The dominance hypothesis attributes the superiority of hybrids to the suppression of undesirable recessive alleles from one parent by dominant alleles from the other. It attributes the poor performance of inbred strains to loss of genetic diversity, with the strains becoming purely homozygous at many loci. The dominance hypothesis was first expressed in 1908 by the geneticist Charles Davenport.[4] Under the dominance hypothesis, deleterious alleles are expected to be maintained in a random-mating population at a selection–mutation balance that would depend on the rate of mutation, the effect of the alleles and the degree to which alleles are expressed in heterozygotes.[5]
• Overdominance hypothesis. Certain combinations of alleles that can be obtained by crossing two inbred strains are advantageous in the heterozygote. The overdominance hypothesis attributes the heterozygote advantage to the survival of many alleles that are recessive and harmful in homozygotes. It attributes the poor performance of inbred strains to a high percentage of these harmful recessives. The overdominance hypothesis was developed independently by Edward M. East (1908)[6] and George Shull (1908).[7] Genetic variation at an overdominant locus is expected to be maintained by balancing selection. The high fitness of heterozygous genotypes favours the persistence of an allelic polymorphism in the population.[5

 

[John Gryphon]

There basically is nothing that is 'pure' originally (there cant be lol). Dogs descended from wolves which like bears descended from miacids..a zillion years ago,although dogs and bears are not compatible.
Dog breeds of today are hybrid culminations and bred to keep them 'pure' even KE`s long little fellows were originally hybrids. Some of the best sporting dogs forebears are of the Heinz varieties. There are some shocking breeds that in hindsight should never have been bred
As above a GSHP x GWHP can make an absolute cracker of a hunting dog but the breeders of both breeds don`t want to know about that of course.
I have had both breeds for companion hunting and the hybrid vigour when crossing them makes for crackers. The GSHP`s softer outlook is hardened by the GWHP`s toughness and then the GWHP`s hard headed prey drive characteristics are detuned somewhat by the GSHP blood to make for a dog that could very well end up being an new "breed"

 

[Keith Edmunds]

There basically is nothing that is 'pure' originally (there cant be lol). Dogs descended from wolves which like bears descended from miacids..a zillion years ago,although dogs and bears are not compatible.
Dog breeds of today are hybrid culminations and bred to keep them 'pure' even KE`s long little fellows were originally hybrids. Some of the best sporting dogs forebears are of the Heinz varieties. There are some shocking breeds that in hindsight should never have been bred
As above a GSHP x GWHP can make an absolute cracker of a hunting dog but the breeders of both breeds don`t want to know about that of course.
I have had both breeds for companion hunting and the hybrid vigour when crossing them makes for crackers. The GSHP`s softer outlook is hardened by the GWHP`s toughness and then the GWHP`s hard headed prey drive characteristics are detuned somewhat by the GSHP blood to make for a dog that could very well end up being an new "breed"

Absolutely....The smooth dachshund did not begin to breed true until the early of the 19th century. The translation 'badger-dog' is not as sacred as some might think as badger were hunted at night above ground, as well as below ground. Up until the late 19th century it is likely that dachshund and dachscbracke could come from the same litter - short-legged given the former name and the long-legged taking the later name. As late as the 1860's Wilhelm von Daake, of Osterode, was adding German bloodhound blood to his dachshund line to improve their trailing capability.

Later still, the wire-haired dachshund was formed from infusions from Scottish/Border Country 'type' terriers and German Pinschers. One wire-haired dachshund breeder of the late 19th century actually founded his kennel on a pair of Dandie Dinmonts that he thought to be wire-haired dachshunds.

It is quite likely that the original dachshund 'type' of the 16th - 18th century shared a lot of common blood with both small 'heeler' type cattle dogs and the 'Turnspits' of the big country houses.