June 1, 2012

Inbreeding

By Rev. John Parks


Someone once said to me, "I'm afraid to try inbreeding, you never know what kind of monstrosity you might get. It's just not normal."
          To that person I was attempted to answer, "With your breeding stock, I'd be afraid to!" Because he had a rather motley -- looking, highstrung bunch of hounds, and inbreeding will simply intensify and concentrate what you've already got. However, if you're riding the crest of your kennel's existence with the best hounds you've ever owned, don't be afraid. Go ahead and make that mating of a little closer related individuals. Be prepared to select only the best to continue the line, however, and cull out all the rest.
          In almost twenty years of Beagling I have done my share of inbreeding, but I have never made a cross "back in" with really closely related individuals. It wasn't because I felt that there was some moral law against it though. It was mainly because I didn't think my stock was up to the standard that I was seeking yet, and so I kept seeking to improve it with more judicious linebreeding and a few outside crosses to get the traits I was seeking.
          And as to deformities, in all those years, and many litters of puppies, I only had one deformed puppy, and that came from an outcross of strictly unrelated individuals! The little female had her female tract and her bowel grown together into one channel, and I didn't think it could be easily fixed by a Vet so I had her put to sleep. Let me repeat though, that this was from an outcross, not inbreeding.
          There is little chance that you will have any problems if you start out with genetically superior individuals. Willet Randall bred the Patch hounds for well over fifty years with very few outcrosses. Somewhere in his writings he indicated that Beaglers would contact him wanting to buy an unrelated pair of hounds. He would answer them that this was impossible because all of his hounds were related. In fact, I would hasten to add that no well known strain or bloodline of Beagles has hounds that are totally unrelated. Mike Yates of Hazlehurst, MS got four hounds from Willet Randall in 1966 and he told me in a letter recently that he had made no outcrosses in twenty-two years!
          Now both of these examples are unusual to be sure, but I bet that even these hounds have had some "duds" culled out along the way. It is the percentage of good hounds that results from a breeding program that really counts. Willet Randall himself said that once a year he would "put to sleep" those that couldn't be kept in his breeding program. In his life story he told about the graveyard where he laid these "rejects." His skill at judging which were going to be the good hounds and his judicious culling was no doubt the secret of his continued success over the years. He didn't just breed any hound. It had to measure up to his rigorous standards.

 As to inbreeding not being "natural," let's look at nature. Among wild animals large or small, inbreeding coupled with the survival of the fittest (or natural culling out of the undesirables and weak ones), has prevailed since the beginning of time. As a result, there has been a pronounced similarity prevailing and continuing within the species. No signs of degeneracy traceable to such inbreeding can be found in most species of wild animals.
          Race horses are another example of pretty pure blood being passed on down generation after generation. Thos much more knowledgeable about horse pedigrees than I could supply interesting and valuable data. I am sure, but I shall not attempt it without a great deal more study. Just ask thoroughbred horse enthusiasts sometime if the winners have any linebreeding or inbreeding showing in their pedigrees. I bet they do.
          Lloyd Brackett tells about milk producing Jersey cattle in his bookPlanned Breeding (on page 24). He says:
"... a daughter of the bull Saturn and the cow Rhea was mated to her full brother, and the resulting heifer was mated to her sire; the daughter of this mating was mated to her full brother and again, the resulting heifer was mated to the same bull; their calf was put to the same bull and their calf yet again to the same sire.
"The result of this intensive and exaggerated inbreeding, by which the last calf had nine crosses of the same original parents (Saturn and Rhea) and no other blood, was Purist, a cow of exceptional vigor and robustness, and an amazing milk producer."
          Another example that Bracket gives is racing pigeons. He notes that British breeders of racing pigeons vie with one another in "wrapping up the blood" of their stock and preserving it in concentrated form. The result is a bird that can exhibit amazing physical endurance for prolonged flight.
Uses and Dangers of Inbreeding

  What are the actual consequences or effects of inbreeding? The primary effect of inbreeding to increase the probability that the offspring will inherit the same qualities from both the sire and the dam. It lowers the percentage of heterozygous (different) genes, and raises the percentage of heterozygous (similar) genes. By doing this, it may "bring to the surface" recessive genes which would otherwise remain hidden. Here is where the oddities sometimes come from, and so consequently, culling out undesirables is imperatives. NOTE: Culling out simply means to fix (neuter or spay) the animal so it is not used for breeding purposes or in very rare, extreme cases, it may mean putting the animal to sleep.
          The percentage of genes most likely to come from each ancestor are (this is Galton's Law): 1/4th from each parent, 1/16th from each grandparent, 1/64th from each great grandparent and so on, with each generation 14th less than the previous. Now do you see why the percentage of similar characteristics is raised with inbreeding?
          So then, some practical uses of inbreeding would be:
  1. To keep the bloodline "pure" and uniform.
  2. To help in sorting out undesirable recessive traits so that they can be eliminated.
  3. To test sires to see if they are good enough to keep using them. This is the severest test of hereditary worth.
  4. It is the surest way of "making the most" of superior animals.
          The most dangerous result of inbreeding is:
  1. It may bring out as many undesirable traits as it does desirable (among humans today there is enough of a probability of undesirable traits that cannot be "culled out" that is unlawful for first cousins or closer to marry).
          Claims that it causes lack of vigor, size, and fertility are largely overblown. Any characteristic can be bred up, or down, strengthened or weakened by inbreeding. It is a powerful tool in the hands of the breeder, so it must be used judiciously.
Summary
          To summarize, regarding inbreeding (and to a lesser degree with linebreeding): All characteristics both good and bad, exist in various degrees in Beagles. The breeder in his matings should attempt to secure and retain the desirable characteristics, and it has been demonstrated that this can be accomplished by judicious breeding, whether it be linebreeding or inbreeding. Results are entirely dependent upon rigorous selection and culling of the stock. Which ones if any, in the litter might carry the genes for the best characteristics can be determined only by testing them as breeder.



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