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Our family has been inbreeding livestock and poultry for over a century
here in the U.S. We've had out share of ups and downs with it, but it
definitely has been our most successful program over the years. I've
been on my own since the 60's, but rely mostly on what I was taught and
observed at home. Regardless of what type of breeding program you
implement, you need to be come an excellent judge or observer of the
species you're working with, first. One must develop the ability to
quickly and accurately detect important differences between individuals.
A successful caretaker or herdsman knows his birds and animals well,
realizing that each possesses a physical individuality that sets it
apart from the rest of the group. These observations have come thru
constant thought as one habitually works with them daily. The practical
side of selection must be emphasized. Whenever a point ceases to be of
practical value, it ceases to have value in selection. One must keep
the practical, profitable, and useful type in mind. In other words,
regardless of species, they must reproduce with ease, grow efficiently,
and produce a desirable end product - - which for most of us is meat,
or a carcass of consumer acceptable composition (meat-bone-fat). The
foundation of any bird or animal is its skeleton. Literally debone a
complete carcass and see where and how the bones are located relative
to the live animal. If individuals are not structurally sound and
naturally functional, I have no time for them. Next, study how the
muscles are draped over that framework. Realize the paradox of optical
illusions and their effect on your observations. Most given muscles
have only a given number of fibres or bundles. They're like a rubber
band. Attached to a long leg bone, they appear very thin because they'r
e stretched out. Take exactly the same muscle mass and attach to a
shorter leg bone, it appears bulging.
Measure the difference in keel length of commercial vs. RHT turkeys.
There is more difference in appearance than in actual muscle mass. True
the BBW has more breast meat, but not in as great a proportion as to
what we shortened the keel. You need to continually evaluate various
types of individuals live, then slaughter them and note what muscle and
skeletal differences created the live variances. Be honest in your
search for facts and be able to recognize them when they exist. One
must have an open mind - prejudices and biased opinions limit competent
decisions. Yet, one must develop in one's mind an image of what those
"easy keeping" ideals look like.
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Actually, at our place it's more a matter of accepting and remembering
what those kind looked like as they occur. One must then wisely and
logically decide how to use all those observations. That's why breeding
remains as much an art as a science. The best computer in the world is
still the one between your ears.
You're wondering when I'm going to talk about inbreeding. Well, an easy
answer would be that it just happens. And, literally, most of the time,
that is precisely true. For generations our family's breeding policy
has simply been, if we need 2 sires, we keep the best young prospect
that we raised and we buy the best one we can find regardless of cost
- - that's part of the price of doing business. If we need 4, we keep
2 and buy 2; if we need 6, we keep 3, and buy 3; and so forth. Next
year we do the same, and so on for each following year. What sets us
apart from others is that each year we compare all the offspring from
each sire as a group and we select the best group as a whole and
discard (sell or slaughter) all the other groups. Then we go into that
group and keep all our replacement sires and dams for next year. Yes,
that's right, they're all half or full-sibs. For me, it's progeny test
ing at its best - - and it's served us well over the years. The only
"fudge factor" we give in to is that in the back of our minds we always
subconsciously factor in a subjective guess of the effect of heterosis
(hybrid vigour) on the outcross half. In our swineherds we're
at 24 generations of brother-sister matings in one breed (they were 1st
in a NASR/NBS/NPPC progeny test this year) and at the 12th on a second
breed (their progeny pen was 4th). It demands cutthroat culling. It's
the same system my Dad was using when land grant college and USDA
scientists were buying pigs from him in the mid-30's and trying to
duplicate his work with all kinds of inbred lines.
Knowing what to discard is the key. You simply mate the rest at random,
let the cards fall where they may, and save the most productive group
as a whole.
Selecting those super individuals is usually just an act of finding
heterozygous birds displaying a unique set of differing genes which
will not breed true, but rather segregate. You can go back and diagram
what you've done, but until you've done it you do not know which mating
group will be best. Of course the more groups mated, the greater
choice you have in selecting the best one and the greater your accuracy
(success) in the long run.
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