No matter what species you're talking about, there are rules that hold true about inbreeding -- the main one being that inbreeding does not *cause* any genetic problems, what it does is allow any problems that are carried recessively in the parents to be expressed in the inbred offspring. Inbreeding can be a very valuable tool in establishing bloodlines or new breeds in that it also allows GOOD genetic traits to be expressed and eventually fixed in the inbred offspring. Inbred sires that are homozygous for desirable traits, and have had the undesirable traits bred out, will almost always throw quality offspring, even with average dams.
Personally I raise rabbits, and practice inbreeding and linebreeding extensively. Through inbreeding I've taken these fuzzbutts from a mediocre pair and a good doe, to herd of approximately 100 animals who consistently win on the show table and produce like a commercial herd instead of a show herd. Along the way, inbreeding has produced some of the very best animals -- and it has also produced some of the very worst. Culling becomes extremely important when inbreeding -- if offspring is kept, they *MUST* be of equal of better quality to the *BEST* parent, otherwise you won't see improvement over several generations. Inbreeding definitely has it's place in a well thought out breeding program, but you have to be willing to cull hard and eliminate animals when it's apparent that there is genetic weakness.
Ann B
> Could anyone let me know about in
> breeding? If we are desiring to
> keep heifers for breeding
> purposes, can they breed with
> their "father"? If so,
> can the third, fourth, generation
> etc stay with the same bull. I
> have received conflicting
> information. I have one cow who
> just recently lost her second
> calf. It was about 3 months old,
> nursed regularly, appeared
> healthy, and I found her dead. I
> have 10-15 other small animals and
> this is the only one that would be
> third generation. Bull is sire of
> cow.
> Thanks.